{"video_id":"vauAJl29xlw","title":"Is this even going to work…","channel":"Linus Tech Tips","show":"Linus Tech Tips","published_at":"2021-05-05T14:53:29Z","duration_s":790,"segments":[{"start_s":0.08,"end_s":6.56,"text":"we just can't convince you guys sometimes after our video debunking a","speaker":null,"is_sponsor":0},{"start_s":4.16,"end_s":12.16,"text":"Corsair rep's claim that stacking radiators is ineffective for improving","speaker":null,"is_sponsor":0},{"start_s":9.28,"end_s":15.12,"text":"cooling you guys told us just how inadequate you felt our test methodology","speaker":null,"is_sponsor":0},{"start_s":14.32,"end_s":21.359,"text":"was you know what okay fine you guys want science we're going to","speaker":null,"is_sponsor":0},{"start_s":18.8,"end_s":25.68,"text":"bring you the science colin here spent two bloody weeks making our own data","speaker":null,"is_sponsor":0},{"start_s":24.56,"end_s":32.48,"text":"logger from scratch and built this behemoth of","speaker":null,"is_sponsor":0},{"start_s":29.92,"end_s":38.079,"text":"a radiator stack along with this wind tunnel just peppered with","speaker":null,"is_sponsor":0},{"start_s":34.96,"end_s":41.44,"text":"sensors to find the definitive final","speaker":null,"is_sponsor":0},{"start_s":38.079,"end_s":42.96,"text":"answer to exactly what effect stacking","speaker":null,"is_sponsor":0},{"start_s":41.44,"end_s":47.76,"text":"radiators has on water temperature tang wants to help","speaker":null,"is_sponsor":0},{"start_s":45.76,"end_s":51.6,"text":"you save money by helping you pay for only the mobile data that you use stick","speaker":null,"is_sponsor":0},{"start_s":50.32,"end_s":57.079,"text":"around until the end of the video to hear about their giveaway or click the link in the video description","speaker":null,"is_sponsor":0},{"start_s":63.76,"end_s":71.68,"text":"for a quick recap back in the day Corsair called us out for the apparently","speaker":null,"is_sponsor":0},{"start_s":69.36,"end_s":77.04,"text":"ineffective way that we were recycling the hot air or stacking the radiators in","speaker":null,"is_sponsor":0},{"start_s":75.36,"end_s":81.84,"text":"our hacc pro now this individual went as far as to","speaker":null,"is_sponsor":0},{"start_s":79.36,"end_s":86.4,"text":"send us images of their flow simulation data to prove their point our logical","speaker":null,"is_sponsor":0},{"start_s":84.0,"end_s":91.759,"text":"answer then was to just build a similarly configured system to prove","speaker":null,"is_sponsor":0},{"start_s":88.799,"end_s":95.92,"text":"that more rads definitely equals more better so we did","speaker":null,"is_sponsor":0},{"start_s":94.159,"end_s":100.64,"text":"and it did but while some of your complaints can be","speaker":null,"is_sponsor":0},{"start_s":98.56,"end_s":104.72,"text":"chalked up to frankly not paying enough attention to the video i get it happens","speaker":null,"is_sponsor":0},{"start_s":103.6,"end_s":110.479,"text":"others seemed to have some merit you guys still","speaker":null,"is_sponsor":0},{"start_s":107.439,"end_s":113.2,"text":"weren't satisfied and so i greenlit a","speaker":null,"is_sponsor":0},{"start_s":110.479,"end_s":117.28,"text":"project to go full crazy on a test rig to isolate the variables that we had","speaker":null,"is_sponsor":0},{"start_s":114.96,"end_s":121.92,"text":"kind of hand waved away last time we started out by reaching out to our","speaker":null,"is_sponsor":0},{"start_s":118.799,"end_s":125.2,"text":"friends at alphacool for seven of their","speaker":null,"is_sponsor":0},{"start_s":121.92,"end_s":127.2,"text":"240 millimeter cross flow rads and","speaker":null,"is_sponsor":0},{"start_s":125.2,"end_s":131.44,"text":"thermistor type temperature probes performance pc also threw some low","speaker":null,"is_sponsor":0},{"start_s":129.44,"end_s":136.0,"text":"profile fittings our way for stacking them together like this so with a little","speaker":null,"is_sponsor":0},{"start_s":133.2,"end_s":140.64,"text":"bit of fabrication and some 3d printed end caps here a wind tunnel was slapped","speaker":null,"is_sponsor":0},{"start_s":138.56,"end_s":144.0,"text":"together from clear acrylic these cross flow rads were specifically chosen","speaker":null,"is_sponsor":0},{"start_s":142.4,"end_s":148.239,"text":"because they give us some really interesting flow options that we may","speaker":null,"is_sponsor":0},{"start_s":146.16,"end_s":152.319,"text":"explore down the line so get subscribed if you want to see more from this test","speaker":null,"is_sponsor":0},{"start_s":150.08,"end_s":157.68,"text":"rig here for this video though we're sticking to serial flow in one out and","speaker":null,"is_sponsor":0},{"start_s":155.44,"end_s":161.92,"text":"then into the next and so on and so forth because that's how most people","speaker":null,"is_sponsor":0},{"start_s":159.76,"end_s":167.519,"text":"would configure a water cooling system if they had multiple radiators at every","speaker":null,"is_sponsor":0},{"start_s":164.72,"end_s":172.0,"text":"single radiator inlet and outlet we've got temperature probes see these puppies","speaker":null,"is_sponsor":0},{"start_s":170.0,"end_s":177.44,"text":"right here these are going to tell us the difference in temperature or delta t","speaker":null,"is_sponsor":0},{"start_s":175.36,"end_s":181.04,"text":"from when the water enters the radiator to when it exits but","speaker":null,"is_sponsor":0},{"start_s":179.519,"end_s":186.08,"text":"we had a problem how do you go about calibrating and","speaker":null,"is_sponsor":0},{"start_s":183.44,"end_s":192.08,"text":"recording the data from all of these sensors colin never content to just take","speaker":null,"is_sponsor":0},{"start_s":188.64,"end_s":193.84,"text":"the easy path decided to create this","speaker":null,"is_sponsor":0},{"start_s":192.08,"end_s":198.959,"text":"this right here with a little bit of code and arduino due chosen for its","speaker":null,"is_sponsor":0},{"start_s":196.56,"end_s":203.84,"text":"large array of analog inputs gives us full control over our data stream oh","speaker":null,"is_sponsor":0},{"start_s":201.92,"end_s":208.08,"text":"yeah and don't forget the absolute beauty of a breadboard right","speaker":null,"is_sponsor":0},{"start_s":205.36,"end_s":212.48,"text":"here that's important the 32-bit atmel processor in here can actually sample","speaker":null,"is_sponsor":0},{"start_s":209.84,"end_s":217.84,"text":"data much faster than we need but we settled on pulling the sensors every 250","speaker":null,"is_sponsor":0},{"start_s":215.12,"end_s":222.4,"text":"milliseconds or four times per sensor long story short the arduino does a","speaker":null,"is_sponsor":0},{"start_s":220.4,"end_s":226.799,"text":"little bit of math and converts the resistance of the thermistor sensor","speaker":null,"is_sponsor":0},{"start_s":224.72,"end_s":229.84,"text":"embedded in each of these fittings into degrees celsius using the steinhart","speaker":null,"is_sponsor":0},{"start_s":228.48,"end_s":234.239,"text":"heart equation if you want to give this a shot yourself by the way we're going to have a link in the description to the","speaker":null,"is_sponsor":0},{"start_s":232.319,"end_s":239.2,"text":"arduino code that we used and a good starting place for some reading now","speaker":null,"is_sponsor":0},{"start_s":237.04,"end_s":243.12,"text":"due to the varying resistance of the sensors themselves","speaker":null,"is_sponsor":0},{"start_s":240.48,"end_s":246.959,"text":"as well as the actual wire connecting them even","speaker":null,"is_sponsor":0},{"start_s":244.64,"end_s":252.959,"text":"the raw output that the arduino sees isn't accurate enough for our purposes","speaker":null,"is_sponsor":0},{"start_s":249.36,"end_s":254.72,"text":"so we added these trim pots right here","speaker":null,"is_sponsor":0},{"start_s":252.959,"end_s":260.079,"text":"numbered zero to eight to allow us to calibrate each sensor to","speaker":null,"is_sponsor":0},{"start_s":257.28,"end_s":263.52,"text":"a known temperature using a water bath once all the sensors were reading within","speaker":null,"is_sponsor":0},{"start_s":261.759,"end_s":267.919,"text":"half a degree of each other the data is pushed out via a serial connection to","speaker":null,"is_sponsor":0},{"start_s":265.6,"end_s":271.6,"text":"this surface laptop running putty an open source serial monitor which can","speaker":null,"is_sponsor":0},{"start_s":269.68,"end_s":276.32,"text":"output all the data to a convenient text file for later processing a relatively","speaker":null,"is_sponsor":0},{"start_s":273.759,"end_s":279.12,"text":"convenient text file okay so now's a good time to take a break from line of","speaker":null,"is_sponsor":0},{"start_s":277.6,"end_s":284.08,"text":"science tips here and hydrate lttstore.com before we get into our heat","speaker":null,"is_sponsor":0},{"start_s":281.919,"end_s":290.479,"text":"source on this test bench right here we've paired a 32 core Threadripper","speaker":null,"is_sponsor":0},{"start_s":286.8,"end_s":292.72,"text":"3970x furnace of a CPU with an NVIDIA","speaker":null,"is_sponsor":0},{"start_s":290.479,"end_s":297.759,"text":"titan v which combined should dump about 500 watts of heat into","speaker":null,"is_sponsor":0},{"start_s":295.759,"end_s":302.72,"text":"our system on the water side of things it's a fairly simple affair with a d5","speaker":null,"is_sponsor":0},{"start_s":300.08,"end_s":307.36,"text":"pump with a custom top as well as a no-name reservoir","speaker":null,"is_sponsor":0},{"start_s":305.44,"end_s":313.28,"text":"so that's the setup let's dive into how everything performed","speaker":null,"is_sponsor":0},{"start_s":310.4,"end_s":318.88,"text":"for our first two tests each radiator was paired with Noctua nff12 fans and we","speaker":null,"is_sponsor":0},{"start_s":316.479,"end_s":323.039,"text":"used our full assembly of seven radiators stacked one after the other","speaker":null,"is_sponsor":0},{"start_s":321.039,"end_s":328.4,"text":"down our wind tunnel air flows over the rads from sensor 0 to sensor 7. kind of","speaker":null,"is_sponsor":0},{"start_s":326.24,"end_s":333.68,"text":"like if our stack was mounted as a front intake on a super weird case that's like","speaker":null,"is_sponsor":0},{"start_s":332.16,"end_s":338.88,"text":"really deep with water flowing from sensor 0 to sensor 7 the radiator with","speaker":null,"is_sponsor":0},{"start_s":336.639,"end_s":342.96,"text":"the hottest water inside it is the one at the very front of the case and off","speaker":null,"is_sponsor":0},{"start_s":341.12,"end_s":347.759,"text":"the hop we can see that most of the cooling happens in this first radiator","speaker":null,"is_sponsor":0},{"start_s":345.68,"end_s":353.44,"text":"represented by the red line this makes sense because it's getting","speaker":null,"is_sponsor":0},{"start_s":349.68,"end_s":355.6,"text":"both the coldest air and the hottest","speaker":null,"is_sponsor":0},{"start_s":353.44,"end_s":360.72,"text":"water coming straight off of our system here the second radiator is orange and then","speaker":null,"is_sponsor":0},{"start_s":358.639,"end_s":366.319,"text":"yellow and then so on with each successive rad doing less and less of","speaker":null,"is_sponsor":0},{"start_s":363.36,"end_s":371.759,"text":"the actual work we hit a point of basically negligible returns at about","speaker":null,"is_sponsor":0},{"start_s":368.88,"end_s":376.08,"text":"radiator six now if we focus in on the initial start of load the first two","speaker":null,"is_sponsor":0},{"start_s":373.759,"end_s":381.039,"text":"minutes we can see here that each radiator gets progressively hotter in","speaker":null,"is_sponsor":0},{"start_s":378.56,"end_s":386.16,"text":"sequence which is to be expected however if we look at just the section","speaker":null,"is_sponsor":0},{"start_s":383.919,"end_s":390.72,"text":"where the load is stopped the results get much more interesting","speaker":null,"is_sponsor":0},{"start_s":388.24,"end_s":396.319,"text":"check this out when firmark is closed the first radiator stays the hottest","speaker":null,"is_sponsor":0},{"start_s":393.44,"end_s":401.28,"text":"which we expect but see how these lines cross over subsequent radiators","speaker":null,"is_sponsor":0},{"start_s":398.88,"end_s":406.639,"text":"this is actually a really cool visual representation of heat soak","speaker":null,"is_sponsor":0},{"start_s":403.919,"end_s":411.84,"text":"so the preheated radiators farther down the line are actually reheating the","speaker":null,"is_sponsor":0},{"start_s":409.52,"end_s":416.8,"text":"water coming from that front rad which as you guys remember is doing most of","speaker":null,"is_sponsor":0},{"start_s":414.0,"end_s":420.72,"text":"the work as it passes through the dark blue line here is the exit water","speaker":null,"is_sponsor":0},{"start_s":418.8,"end_s":425.759,"text":"temperature and it actually comes out hotter than the other rads in the series","speaker":null,"is_sponsor":0},{"start_s":424.0,"end_s":430.72,"text":"zooming out a little bit more shows the middle radiators eventually equalize and","speaker":null,"is_sponsor":0},{"start_s":428.4,"end_s":433.84,"text":"fall into order once again so seeing heat soak right here in the data is","speaker":null,"is_sponsor":0},{"start_s":432.639,"end_s":440.08,"text":"super cool well more like 39.5 degrees not that cool but","speaker":null,"is_sponsor":0},{"start_s":437.68,"end_s":444.639,"text":"hey who's counting got him of course one way to counteract","speaker":null,"is_sponsor":0},{"start_s":442.4,"end_s":449.28,"text":"this reliance on the front radiator is to run the water the other way as many","speaker":null,"is_sponsor":0},{"start_s":447.36,"end_s":456.0,"text":"of our viewers recommended last time around that puts the freshest air into","speaker":null,"is_sponsor":0},{"start_s":453.36,"end_s":459.44,"text":"the last radiator for the water to flow through","speaker":null,"is_sponsor":0},{"start_s":456.88,"end_s":465.52,"text":"so the only variable between test one and test two is that we reversed the","speaker":null,"is_sponsor":0},{"start_s":462.16,"end_s":467.599,"text":"water flow direction in the loop this is","speaker":null,"is_sponsor":0},{"start_s":465.52,"end_s":472.88,"text":"generally considered to be the better way to stack and according to our","speaker":null,"is_sponsor":0},{"start_s":470.0,"end_s":477.36,"text":"testing that checks out by flipping the flow all the rads come up to temperature","speaker":null,"is_sponsor":0},{"start_s":475.44,"end_s":482.08,"text":"more slowly as the stack gets progressively hotter and if we overlay","speaker":null,"is_sponsor":0},{"start_s":479.52,"end_s":486.16,"text":"the two water exit temps and offset to account for the ambient slash idle","speaker":null,"is_sponsor":0},{"start_s":484.24,"end_s":490.639,"text":"temperature of the system the outlet temperature does show minor improvements","speaker":null,"is_sponsor":0},{"start_s":488.479,"end_s":496.08,"text":"versus test one's flow direction cool quick takeaways then it appears that for","speaker":null,"is_sponsor":0},{"start_s":492.96,"end_s":497.919,"text":"this combination of CPU and GPU at least","speaker":null,"is_sponsor":0},{"start_s":496.08,"end_s":502.0,"text":"by the time the water reaches the six radiator we've imparted as much heat","speaker":null,"is_sponsor":0},{"start_s":499.919,"end_s":505.84,"text":"into the air as we're going to at the highest water temp we were seeing a","speaker":null,"is_sponsor":0},{"start_s":503.36,"end_s":510.08,"text":"delta t of about four degrees from the first rad to the sixth the last one that","speaker":null,"is_sponsor":0},{"start_s":508.24,"end_s":513.839,"text":"was actually making a difference give or take a half a degree","speaker":null,"is_sponsor":0},{"start_s":511.52,"end_s":519.2,"text":"and we also see that the majority of the work is being done by the first radiator","speaker":null,"is_sponsor":0},{"start_s":516.8,"end_s":524.64,"text":"so our Corsair representatives point about the small gains from stacking","speaker":null,"is_sponsor":0},{"start_s":521.68,"end_s":528.399,"text":"being offset by the reduction in airflow that comes from adding more restriction","speaker":null,"is_sponsor":0},{"start_s":526.56,"end_s":533.12,"text":"and more fins does seem to be fair","speaker":null,"is_sponsor":0},{"start_s":530.64,"end_s":538.88,"text":"but it's also true that there is still performance to be gained so","speaker":null,"is_sponsor":0},{"start_s":536.32,"end_s":543.839,"text":"for our third scenario we moved on to a more sensible setup right here you're","speaker":null,"is_sponsor":0},{"start_s":541.12,"end_s":546.88,"text":"looking at one bank of fans and two radiators and","speaker":null,"is_sponsor":0},{"start_s":545.76,"end_s":551.519,"text":"here there's definitely less volume in the","speaker":null,"is_sponsor":0},{"start_s":548.88,"end_s":555.92,"text":"loop so we see the temperatures rise much quicker overall we hit a peak temp","speaker":null,"is_sponsor":0},{"start_s":554.08,"end_s":559.68,"text":"of 38 and a half degrees after 10 minutes of load","speaker":null,"is_sponsor":0},{"start_s":557.279,"end_s":566.0,"text":"but when we ran the same test with a single radiator we also hit","speaker":null,"is_sponsor":0},{"start_s":563.08,"end_s":571.04,"text":"38.5 degrees here's where it gets really interesting","speaker":null,"is_sponsor":0},{"start_s":568.0,"end_s":573.12,"text":"for a sanity check we charted the change","speaker":null,"is_sponsor":0},{"start_s":571.04,"end_s":578.399,"text":"in temperature from the inlet to outlet side of both the single and the dual","speaker":null,"is_sponsor":0},{"start_s":575.04,"end_s":580.88,"text":"tests so a higher delta t on one system","speaker":null,"is_sponsor":0},{"start_s":578.399,"end_s":584.72,"text":"would mean that that particular one is more effective now the data is a bit","speaker":null,"is_sponsor":0},{"start_s":582.72,"end_s":588.56,"text":"noisy for one of the tests but regardless they look pretty well aligned","speaker":null,"is_sponsor":0},{"start_s":587.839,"end_s":594.24,"text":"so in my eyes that's pretty definitive when","speaker":null,"is_sponsor":0},{"start_s":591.44,"end_s":598.72,"text":"it comes to one rad versus two assuming you've only got one set of fans","speaker":null,"is_sponsor":0},{"start_s":596.32,"end_s":603.519,"text":"a second radiator isn't really going to do anything for you besides add some","speaker":null,"is_sponsor":0},{"start_s":600.88,"end_s":608.399,"text":"thermal capacity in the form of metal and water mass so i can't believe i'm","speaker":null,"is_sponsor":0},{"start_s":606.56,"end_s":612.24,"text":"saying it but i was wrong i've been saying that a lot","speaker":null,"is_sponsor":0},{"start_s":611.04,"end_s":617.36,"text":"lately at least i was wrong for this test now","speaker":null,"is_sponsor":0},{"start_s":615.36,"end_s":622.32,"text":"as i alluded to earlier a lot of you missed this but the minecraft server did","speaker":null,"is_sponsor":0},{"start_s":620.079,"end_s":626.72,"text":"perform better with three versus two radiators under full load and for that","speaker":null,"is_sponsor":0},{"start_s":624.399,"end_s":631.279,"text":"matter so did the hack pro we believe this comes down to either having enough","speaker":null,"is_sponsor":0},{"start_s":629.2,"end_s":636.959,"text":"airflow to utilize the extra surface area or having a mix of preheated air","speaker":null,"is_sponsor":0},{"start_s":634.8,"end_s":641.6,"text":"and ambient air mixed in because a typical computer case is not actually a","speaker":null,"is_sponsor":0},{"start_s":639.6,"end_s":646.32,"text":"sealed system but we still learned a lot here first is that more rads does not","speaker":null,"is_sponsor":0},{"start_s":644.64,"end_s":650.56,"text":"always mean more better in the case of our one rad versus two in the wind","speaker":null,"is_sponsor":0},{"start_s":648.0,"end_s":654.64,"text":"tunnel it appears that Corsair is right in that adding a second radiator doesn't","speaker":null,"is_sponsor":0},{"start_s":652.16,"end_s":658.16,"text":"do anything the data we gathered proves this and this is with a bank of static","speaker":null,"is_sponsor":0},{"start_s":656.56,"end_s":662.48,"text":"pressure optimized fans these are not like pinner crappy fans second some of","speaker":null,"is_sponsor":0},{"start_s":660.8,"end_s":667.04,"text":"the perceived gains from radiator stacking could simply come down to","speaker":null,"is_sponsor":0},{"start_s":664.399,"end_s":670.959,"text":"flawed tests where the system is not allowed to reach equilibrium making it","speaker":null,"is_sponsor":0},{"start_s":669.36,"end_s":674.88,"text":"seem like it's running cooler but if they had just left it for longer that","speaker":null,"is_sponsor":0},{"start_s":672.8,"end_s":678.24,"text":"water would have eventually heated up that's an easy mistake to make because","speaker":null,"is_sponsor":0},{"start_s":676.8,"end_s":682.0,"text":"the increase in thermal mass of the radiators themselves as well as their","speaker":null,"is_sponsor":0},{"start_s":680.0,"end_s":685.2,"text":"water capacity can make this kind of testing take a really","speaker":null,"is_sponsor":0},{"start_s":684.24,"end_s":691.44,"text":"long time third and finally you can still get","speaker":null,"is_sponsor":0},{"start_s":688.48,"end_s":696.24,"text":"a benefit from stacking but only with a correctly configured system that moves","speaker":null,"is_sponsor":0},{"start_s":693.76,"end_s":701.04,"text":"the air fast enough to maintain a meaningful difference in temperature","speaker":null,"is_sponsor":0},{"start_s":698.24,"end_s":705.519,"text":"between the air and the water in the last radiator in the stack","speaker":null,"is_sponsor":0},{"start_s":703.839,"end_s":711.04,"text":"so i really wanted to come out and say boom headshot","speaker":null,"is_sponsor":0},{"start_s":707.36,"end_s":713.12,"text":"gotcha Corsair but when we isolated","speaker":null,"is_sponsor":0},{"start_s":711.04,"end_s":717.92,"text":"everything down like this the results didn't quite match up with","speaker":null,"is_sponsor":0},{"start_s":715.44,"end_s":723.44,"text":"that this is not what i expected but in a way that's kind of great too and i","speaker":null,"is_sponsor":0},{"start_s":720.8,"end_s":728.079,"text":"learned something today kind of great like our sponsor ting does","speaker":null,"is_sponsor":0},{"start_s":726.24,"end_s":732.399,"text":"mobile phone service differently there's no contracts overage fees or any other","speaker":null,"is_sponsor":0},{"start_s":730.24,"end_s":736.56,"text":"carrier tricks you just pay a fair price for the talk text and data that you use","speaker":null,"is_sponsor":0},{"start_s":734.48,"end_s":740.8,"text":"each month and it's especially great if you're stuck at home using wi-fi instead","speaker":null,"is_sponsor":0},{"start_s":738.639,"end_s":744.32,"text":"of mobile data with ting you've got complete control over your cell phone","speaker":null,"is_sponsor":0},{"start_s":742.399,"end_s":748.56,"text":"account so you can set alerts and caps for every device and they've got","speaker":null,"is_sponsor":0},{"start_s":746.399,"end_s":753.92,"text":"nationwide lte coverage using t-mobile sprint and verizon that means great","speaker":null,"is_sponsor":0},{"start_s":751.44,"end_s":756.959,"text":"coverage from coast to coast almost any phone will work with ting from an","speaker":null,"is_sponsor":0},{"start_s":755.279,"end_s":762.56,"text":"ancient motorola razer sitting in your basement to the latest iphone 11 series","speaker":null,"is_sponsor":0},{"start_s":759.76,"end_s":765.68,"text":"and there's a giveaway over at ting.com if you guys head over there right now","speaker":null,"is_sponsor":0},{"start_s":763.68,"end_s":770.839,"text":"you've got a chance to win 20 ting swag bags or their ultimate giveaway a galaxy","speaker":null,"is_sponsor":0},{"start_s":768.399,"end_s":774.88,"text":"note 10 plus just enter at mobile.ting.com Linus giveaway or at the","speaker":null,"is_sponsor":0},{"start_s":773.36,"end_s":777.76,"text":"link in the video description you'll find the full details and when it ends","speaker":null,"is_sponsor":0},{"start_s":776.639,"end_s":782.88,"text":"down below so thanks for watching guys i want to throw you guys over to the hack pro","speaker":null,"is_sponsor":0},{"start_s":781.2,"end_s":786.88,"text":"series which actually inspired this whole experiment you can check out how","speaker":null,"is_sponsor":0},{"start_s":785.12,"end_s":791.6,"text":"difficult it was to jam water cooling into that case however effective or","speaker":null,"is_sponsor":0},{"start_s":788.48,"end_s":791.6,"text":"ineffective it ended up being","speaker":null,"is_sponsor":0}],"full_text":"we just can't convince you guys sometimes after our video debunking a Corsair rep's claim that stacking radiators is ineffective for improving cooling you guys told us just how inadequate you felt our test methodology was you know what okay fine you guys want science we're going to bring you the science colin here spent two bloody weeks making our own data logger from scratch and built this behemoth of a radiator stack along with this wind tunnel just peppered with sensors to find the definitive final answer to exactly what effect stacking radiators has on water temperature tang wants to help you save money by helping you pay for only the mobile data that you use stick around until the end of the video to hear about their giveaway or click the link in the video description for a quick recap back in the day Corsair called us out for the apparently ineffective way that we were recycling the hot air or stacking the radiators in our hacc pro now this individual went as far as to send us images of their flow simulation data to prove their point our logical answer then was to just build a similarly configured system to prove that more rads definitely equals more better so we did and it did but while some of your complaints can be chalked up to frankly not paying enough attention to the video i get it happens others seemed to have some merit you guys still weren't satisfied and so i greenlit a project to go full crazy on a test rig to isolate the variables that we had kind of hand waved away last time we started out by reaching out to our friends at alphacool for seven of their 240 millimeter cross flow rads and thermistor type temperature probes performance pc also threw some low profile fittings our way for stacking them together like this so with a little bit of fabrication and some 3d printed end caps here a wind tunnel was slapped together from clear acrylic these cross flow rads were specifically chosen because they give us some really interesting flow options that we may explore down the line so get subscribed if you want to see more from this test rig here for this video though we're sticking to serial flow in one out and then into the next and so on and so forth because that's how most people would configure a water cooling system if they had multiple radiators at every single radiator inlet and outlet we've got temperature probes see these puppies right here these are going to tell us the difference in temperature or delta t from when the water enters the radiator to when it exits but we had a problem how do you go about calibrating and recording the data from all of these sensors colin never content to just take the easy path decided to create this this right here with a little bit of code and arduino due chosen for its large array of analog inputs gives us full control over our data stream oh yeah and don't forget the absolute beauty of a breadboard right here that's important the 32-bit atmel processor in here can actually sample data much faster than we need but we settled on pulling the sensors every 250 milliseconds or four times per sensor long story short the arduino does a little bit of math and converts the resistance of the thermistor sensor embedded in each of these fittings into degrees celsius using the steinhart heart equation if you want to give this a shot yourself by the way we're going to have a link in the description to the arduino code that we used and a good starting place for some reading now due to the varying resistance of the sensors themselves as well as the actual wire connecting them even the raw output that the arduino sees isn't accurate enough for our purposes so we added these trim pots right here numbered zero to eight to allow us to calibrate each sensor to a known temperature using a water bath once all the sensors were reading within half a degree of each other the data is pushed out via a serial connection to this surface laptop running putty an open source serial monitor which can output all the data to a convenient text file for later processing a relatively convenient text file okay so now's a good time to take a break from line of science tips here and hydrate lttstore.com before we get into our heat source on this test bench right here we've paired a 32 core Threadripper 3970x furnace of a CPU with an NVIDIA titan v which combined should dump about 500 watts of heat into our system on the water side of things it's a fairly simple affair with a d5 pump with a custom top as well as a no-name reservoir so that's the setup let's dive into how everything performed for our first two tests each radiator was paired with Noctua nff12 fans and we used our full assembly of seven radiators stacked one after the other down our wind tunnel air flows over the rads from sensor 0 to sensor 7. kind of like if our stack was mounted as a front intake on a super weird case that's like really deep with water flowing from sensor 0 to sensor 7 the radiator with the hottest water inside it is the one at the very front of the case and off the hop we can see that most of the cooling happens in this first radiator represented by the red line this makes sense because it's getting both the coldest air and the hottest water coming straight off of our system here the second radiator is orange and then yellow and then so on with each successive rad doing less and less of the actual work we hit a point of basically negligible returns at about radiator six now if we focus in on the initial start of load the first two minutes we can see here that each radiator gets progressively hotter in sequence which is to be expected however if we look at just the section where the load is stopped the results get much more interesting check this out when firmark is closed the first radiator stays the hottest which we expect but see how these lines cross over subsequent radiators this is actually a really cool visual representation of heat soak so the preheated radiators farther down the line are actually reheating the water coming from that front rad which as you guys remember is doing most of the work as it passes through the dark blue line here is the exit water temperature and it actually comes out hotter than the other rads in the series zooming out a little bit more shows the middle radiators eventually equalize and fall into order once again so seeing heat soak right here in the data is super cool well more like 39.5 degrees not that cool but hey who's counting got him of course one way to counteract this reliance on the front radiator is to run the water the other way as many of our viewers recommended last time around that puts the freshest air into the last radiator for the water to flow through so the only variable between test one and test two is that we reversed the water flow direction in the loop this is generally considered to be the better way to stack and according to our testing that checks out by flipping the flow all the rads come up to temperature more slowly as the stack gets progressively hotter and if we overlay the two water exit temps and offset to account for the ambient slash idle temperature of the system the outlet temperature does show minor improvements versus test one's flow direction cool quick takeaways then it appears that for this combination of CPU and GPU at least by the time the water reaches the six radiator we've imparted as much heat into the air as we're going to at the highest water temp we were seeing a delta t of about four degrees from the first rad to the sixth the last one that was actually making a difference give or take a half a degree and we also see that the majority of the work is being done by the first radiator so our Corsair representatives point about the small gains from stacking being offset by the reduction in airflow that comes from adding more restriction and more fins does seem to be fair but it's also true that there is still performance to be gained so for our third scenario we moved on to a more sensible setup right here you're looking at one bank of fans and two radiators and here there's definitely less volume in the loop so we see the temperatures rise much quicker overall we hit a peak temp of 38 and a half degrees after 10 minutes of load but when we ran the same test with a single radiator we also hit 38.5 degrees here's where it gets really interesting for a sanity check we charted the change in temperature from the inlet to outlet side of both the single and the dual tests so a higher delta t on one system would mean that that particular one is more effective now the data is a bit noisy for one of the tests but regardless they look pretty well aligned so in my eyes that's pretty definitive when it comes to one rad versus two assuming you've only got one set of fans a second radiator isn't really going to do anything for you besides add some thermal capacity in the form of metal and water mass so i can't believe i'm saying it but i was wrong i've been saying that a lot lately at least i was wrong for this test now as i alluded to earlier a lot of you missed this but the minecraft server did perform better with three versus two radiators under full load and for that matter so did the hack pro we believe this comes down to either having enough airflow to utilize the extra surface area or having a mix of preheated air and ambient air mixed in because a typical computer case is not actually a sealed system but we still learned a lot here first is that more rads does not always mean more better in the case of our one rad versus two in the wind tunnel it appears that Corsair is right in that adding a second radiator doesn't do anything the data we gathered proves this and this is with a bank of static pressure optimized fans these are not like pinner crappy fans second some of the perceived gains from radiator stacking could simply come down to flawed tests where the system is not allowed to reach equilibrium making it seem like it's running cooler but if they had just left it for longer that water would have eventually heated up that's an easy mistake to make because the increase in thermal mass of the radiators themselves as well as their water capacity can make this kind of testing take a really long time third and finally you can still get a benefit from stacking but only with a correctly configured system that moves the air fast enough to maintain a meaningful difference in temperature between the air and the water in the last radiator in the stack so i really wanted to come out and say boom headshot gotcha Corsair but when we isolated everything down like this the results didn't quite match up with that this is not what i expected but in a way that's kind of great too and i learned something today kind of great like our sponsor ting does mobile phone service differently there's no contracts overage fees or any other carrier tricks you just pay a fair price for the talk text and data that you use each month and it's especially great if you're stuck at home using wi-fi instead of mobile data with ting you've got complete control over your cell phone account so you can set alerts and caps for every device and they've got nationwide lte coverage using t-mobile sprint and verizon that means great coverage from coast to coast almost any phone will work with ting from an ancient motorola razer sitting in your basement to the latest iphone 11 series and there's a giveaway over at ting.com if you guys head over there right now you've got a chance to win 20 ting swag bags or their ultimate giveaway a galaxy note 10 plus just enter at mobile.ting.com Linus giveaway or at the link in the video description you'll find the full details and when it ends down below so thanks for watching guys i want to throw you guys over to the hack pro series which actually inspired this whole experiment you can check out how difficult it was to jam water cooling into that case however effective or ineffective it ended up being"}