{"video_id":"rctaLgK5stA","title":"PCIe Lanes - PCIe 8x vs 16x in SLI","channel":"Linus Tech Tips","show":"Linus Tech Tips","published_at":"2015-05-07T14:53:29Z","duration_s":483,"segments":[{"start_s":0.08,"end_s":7.2,"text":"so the other day i was shopping for a state-of-the-art CPU for my gaming and","speaker":null,"is_sponsor":0},{"start_s":4.48,"end_s":13.759,"text":"productivity pc when i realized that Intel's latest 5820k and 5930k","speaker":null,"is_sponsor":0},{"start_s":11.44,"end_s":18.08,"text":"both have six processing cores with hyper threading both have 15 megs of","speaker":null,"is_sponsor":0},{"start_s":16.16,"end_s":25.76,"text":"cash they have a clock speed difference of only six percent and yet the","speaker":null,"is_sponsor":0},{"start_s":20.72,"end_s":25.76,"text":"difference in retail price is around 200","speaker":null,"is_sponsor":0},{"start_s":26.4,"end_s":34.96,"text":"oh there's the gotcha the 5820k only has 28","speaker":null,"is_sponsor":0},{"start_s":32.16,"end_s":39.44,"text":"pci express gen 3 lanes you know the electrical connections behind the slots","speaker":null,"is_sponsor":0},{"start_s":37.2,"end_s":45.84,"text":"that we use for graphics cards and other expansion cards compared to 40 on the","speaker":null,"is_sponsor":0},{"start_s":42.84,"end_s":48.719,"text":"5930k what a strange way for Intel to","speaker":null,"is_sponsor":0},{"start_s":45.84,"end_s":52.0,"text":"differentiate its mid-tier 2011 3 CPU from its entry-level one","speaker":null,"is_sponsor":0},{"start_s":57.28,"end_s":65.199,"text":"Corsair gaming RGB keyboards feature precision cherry mx RGB key switches for","speaker":null,"is_sponsor":0},{"start_s":62.44,"end_s":69.84,"text":"16.8 million color per key backlighting for virtually unlimited customization","speaker":null,"is_sponsor":0},{"start_s":67.68,"end_s":75.36,"text":"click now to learn more let's start with a brief explanation of what pci express","speaker":null,"is_sponsor":0},{"start_s":72.159,"end_s":78.159,"text":"or PCIe lanes are and what they're good","speaker":null,"is_sponsor":0},{"start_s":75.36,"end_s":85.2,"text":"for unlike previous expansion slots like agp and pci pci express has a physical","speaker":null,"is_sponsor":0},{"start_s":81.759,"end_s":87.6,"text":"size and an electrical operating mode","speaker":null,"is_sponsor":0},{"start_s":85.2,"end_s":91.28,"text":"that can be independent from each other power is provided by the pins near the","speaker":null,"is_sponsor":0},{"start_s":89.36,"end_s":97.119,"text":"key in the connector and the rest of the connector is used or not used to provide","speaker":null,"is_sponsor":0},{"start_s":94.479,"end_s":101.439,"text":"more or less bandwidth to the device that is plugged into it the more","speaker":null,"is_sponsor":0},{"start_s":98.96,"end_s":108.64,"text":"bandwidth the more lanes are said to be being used for communication the most","speaker":null,"is_sponsor":0},{"start_s":103.36,"end_s":110.96,"text":"common speeds are 1x 4x 8x and 16x so","speaker":null,"is_sponsor":0},{"start_s":108.64,"end_s":117.36,"text":"here's a cool fact the different bus width cards and slots are actually","speaker":null,"is_sponsor":0},{"start_s":114.799,"end_s":123.6,"text":"interoperable that means that installing a 1x card in a 16x slot is fine and you","speaker":null,"is_sponsor":0},{"start_s":121.2,"end_s":129.28,"text":"can even go the other way around in this video i cut out the back of a smaller","speaker":null,"is_sponsor":0},{"start_s":126.24,"end_s":131.76,"text":"slot and put a larger card into it all","speaker":null,"is_sponsor":0},{"start_s":129.28,"end_s":135.76,"text":"that happens is that both the slot and the card will now operate at the speed","speaker":null,"is_sponsor":0},{"start_s":133.68,"end_s":141.76,"text":"of the lowest link in the chain so that's what's going to happen if we","speaker":null,"is_sponsor":0},{"start_s":137.44,"end_s":145.04,"text":"plug our PCIe 16x graphics card into","speaker":null,"is_sponsor":0},{"start_s":141.76,"end_s":147.92,"text":"what appears to be a 16x slot but if the","speaker":null,"is_sponsor":0},{"start_s":145.04,"end_s":152.72,"text":"CPU in our system doesn't have enough pci express lanes to provide the full 16","speaker":null,"is_sponsor":0},{"start_s":150.56,"end_s":157.28,"text":"lanes your motherboard manual will give you more specifics with a slot by slot","speaker":null,"is_sponsor":0},{"start_s":155.36,"end_s":162.8,"text":"breakdown of how it's going to work but basically it'll simply interface with","speaker":null,"is_sponsor":0},{"start_s":159.44,"end_s":165.28,"text":"your pc at a lower speed usually 8x","speaker":null,"is_sponsor":0},{"start_s":162.8,"end_s":169.28,"text":"well that sounds horrible Linus won't cutting the link speed to my graphics","speaker":null,"is_sponsor":0},{"start_s":166.8,"end_s":173.76,"text":"card in half tank its performance not necessarily we're on the third","speaker":null,"is_sponsor":0},{"start_s":171.44,"end_s":177.92,"text":"generation of pci express with each new generation doubling the theoretical","speaker":null,"is_sponsor":0},{"start_s":176.0,"end_s":184.64,"text":"speed of the previous one that means a modern gen 3 PCIe 16x slot can","speaker":null,"is_sponsor":0},{"start_s":181.76,"end_s":189.76,"text":"communicate four times faster than an original gen 1 16x slot or another way","speaker":null,"is_sponsor":0},{"start_s":187.36,"end_s":195.84,"text":"of thinking about this is that a gen 3 4x slot is equivalent to a gen 2 8x or a","speaker":null,"is_sponsor":0},{"start_s":193.28,"end_s":199.2,"text":"gen 1 16x slot but while we already know that from","speaker":null,"is_sponsor":0},{"start_s":197.68,"end_s":204.239,"text":"countless articles that exist on the topic in the past that no previous","speaker":null,"is_sponsor":0},{"start_s":201.36,"end_s":208.879,"text":"generation of 8x slot has bottlenecked a then modern high-end graphics card with","speaker":null,"is_sponsor":0},{"start_s":206.64,"end_s":213.84,"text":"x99's positioning as the high-performance platform of choice for","speaker":null,"is_sponsor":0},{"start_s":210.959,"end_s":218.879,"text":"enthusiasts and for gamers i think it's fair to say that folks may be running","speaker":null,"is_sponsor":0},{"start_s":215.599,"end_s":221.28,"text":"not just one but two or even more","speaker":null,"is_sponsor":0},{"start_s":218.879,"end_s":226.879,"text":"graphics cards at a time and this is where concerns start to arise especially","speaker":null,"is_sponsor":0},{"start_s":223.92,"end_s":231.36,"text":"given that AMD and i suspect also NVIDIA is starting to do more inter-card","speaker":null,"is_sponsor":0},{"start_s":228.879,"end_s":236.48,"text":"communication over pci express when running in crossfire and again i suspect","speaker":null,"is_sponsor":0},{"start_s":233.599,"end_s":241.519,"text":"sli versus relying on those dedicated connectors on the top of the cards","speaker":null,"is_sponsor":0},{"start_s":238.879,"end_s":244.799,"text":"so let's introduce the test to eliminate the variable of the slightly different","speaker":null,"is_sponsor":0},{"start_s":243.04,"end_s":248.0,"text":"clock speed of the two cpus and since overclocking k-series chips is so easy","speaker":null,"is_sponsor":0},{"start_s":246.56,"end_s":251.76,"text":"these days we're gonna run both processors at four gigahertz a very","speaker":null,"is_sponsor":0},{"start_s":250.08,"end_s":255.12,"text":"conservative overclock that anyone should be able to attain for the rest of","speaker":null,"is_sponsor":0},{"start_s":253.599,"end_s":258.88,"text":"the bench we've got a Gigabyte x99 gaming five four-way sli compatible","speaker":null,"is_sponsor":0},{"start_s":256.72,"end_s":261.919,"text":"motherboard with 16 gigs of ddr4 2400 megahertz memory from adata thanks to","speaker":null,"is_sponsor":0},{"start_s":260.639,"end_s":268.479,"text":"both of them for providing the hardware for the test bench we're going to be using four NVIDIA GeForce gtx 980 4gb","speaker":null,"is_sponsor":0},{"start_s":266.639,"end_s":272.72,"text":"graphics cards and we're going to be running all this off of course our ax","speaker":null,"is_sponsor":0},{"start_s":270.08,"end_s":278.24,"text":"1500i power supply so that nothing melts during the benchmarking process and here","speaker":null,"is_sponsor":0},{"start_s":275.6,"end_s":281.68,"text":"are the numbers fraps was used to take average frame rates for each of our","speaker":null,"is_sponsor":0},{"start_s":279.919,"end_s":286.08,"text":"standard test runs and all games were run at 4k on pretty demanding settings","speaker":null,"is_sponsor":0},{"start_s":284.8,"end_s":291.199,"text":"to ensure that we were pushing the hardware as hard as possible as expected","speaker":null,"is_sponsor":0},{"start_s":289.44,"end_s":297.68,"text":"a single graphics card config is not affected in any way since it's running","speaker":null,"is_sponsor":0},{"start_s":293.28,"end_s":301.88,"text":"in 16x mode on either CPU but dual cards","speaker":null,"is_sponsor":0},{"start_s":297.68,"end_s":304.479,"text":"will be running at 8x8x on a 5820k and","speaker":null,"is_sponsor":0},{"start_s":301.88,"end_s":309.36,"text":"16x16x so an effective doubling on a 5930k so i guess as much as it might be","speaker":null,"is_sponsor":0},{"start_s":307.28,"end_s":314.72,"text":"a little bit more counterintuitive they both ran the same so there you go","speaker":null,"is_sponsor":0},{"start_s":311.759,"end_s":319.039,"text":"in three-way sli both cpus have to give up at least one 16x slot but again the","speaker":null,"is_sponsor":0},{"start_s":317.44,"end_s":323.6,"text":"results are not really affected in any way beyond sort of your standard","speaker":null,"is_sponsor":0},{"start_s":321.68,"end_s":329.039,"text":"variance from one run to another and then finally in four-way sli we see oh","speaker":null,"is_sponsor":0},{"start_s":326.88,"end_s":333.199,"text":"actually there's a difference here as you may or may not have noticed our 28","speaker":null,"is_sponsor":0},{"start_s":330.88,"end_s":339.039,"text":"lien CPU doesn't have any numbers for 4-way sli NVIDIA requires graphics cards","speaker":null,"is_sponsor":0},{"start_s":336.56,"end_s":345.039,"text":"to be plugged into an 8x slot at least for sli certification so only 40 lane","speaker":null,"is_sponsor":0},{"start_s":342.08,"end_s":348.8,"text":"cpus have support for this configuration however it should be noted that even at","speaker":null,"is_sponsor":0},{"start_s":346.96,"end_s":354.56,"text":"4k the benefit of a fourth card is fairly small and three-way remains our","speaker":null,"is_sponsor":0},{"start_s":351.759,"end_s":358.24,"text":"recommended max config even if you feel the need to spend over a thousand","speaker":null,"is_sponsor":0},{"start_s":356.16,"end_s":362.0,"text":"dollars on a bunch of graphics cards to put in your system it should be noted","speaker":null,"is_sponsor":0},{"start_s":360.24,"end_s":365.919,"text":"that AMD does not have the same limitation for crossfire so you could","speaker":null,"is_sponsor":0},{"start_s":363.759,"end_s":371.28,"text":"run four graphics cards if you really wanted to in that case but our","speaker":null,"is_sponsor":0},{"start_s":367.68,"end_s":373.36,"text":"recommendation remains the same anyhow","speaker":null,"is_sponsor":0},{"start_s":371.28,"end_s":377.919,"text":"so that's the story or at least most of it for gamers anyway compared to the","speaker":null,"is_sponsor":0},{"start_s":375.36,"end_s":382.639,"text":"mainstream z97 platform where it should be noted that even the highest end cpus","speaker":null,"is_sponsor":0},{"start_s":379.84,"end_s":389.759,"text":"have a mere 16 lanes Intel's enthusiast x99 platform in general and the core i7","speaker":null,"is_sponsor":0},{"start_s":386.08,"end_s":392.24,"text":"5820k CPU in particular is a great","speaker":null,"is_sponsor":0},{"start_s":389.759,"end_s":396.96,"text":"choice even for multi graphics card gamers if they want to reap the benefits","speaker":null,"is_sponsor":0},{"start_s":394.319,"end_s":401.28,"text":"of an extra two processing course ddr4 memory and higher overall memory","speaker":null,"is_sponsor":0},{"start_s":398.96,"end_s":404.72,"text":"capacity limits things do get a little bit dicey for","speaker":null,"is_sponsor":0},{"start_s":402.8,"end_s":408.4,"text":"non-gamers though when it comes to other pci expansions so make sure that you","speaker":null,"is_sponsor":0},{"start_s":406.8,"end_s":413.28,"text":"consult the manual of the motherboard you want before investing in this","speaker":null,"is_sponsor":0},{"start_s":410.639,"end_s":418.319,"text":"particular CPU because you may find that the m.2 high speed storage slots","speaker":null,"is_sponsor":0},{"start_s":416.24,"end_s":424.16,"text":"and in some cases even built on ports like SATA express and usb 3 headers","speaker":null,"is_sponsor":0},{"start_s":421.12,"end_s":427.039,"text":"might not work with too many pci express","speaker":null,"is_sponsor":0},{"start_s":424.16,"end_s":431.759,"text":"cards plugged in or even be available at all with a 28 lane CPU so if in doubt","speaker":null,"is_sponsor":0},{"start_s":430.16,"end_s":435.759,"text":"head over to the cpus and motherboard section of the Linus techtips.com forum","speaker":null,"is_sponsor":0},{"start_s":433.52,"end_s":438.88,"text":"where our helpful community will get you sorted out","speaker":null,"is_sponsor":0},{"start_s":437.199,"end_s":443.039,"text":"thanks for watching guys i hope this video put to rest some of the concerns","speaker":null,"is_sponsor":0},{"start_s":441.12,"end_s":447.28,"text":"about oh no the affordable one doesn't have enough pci express lanes i hope you","speaker":null,"is_sponsor":0},{"start_s":445.28,"end_s":450.56,"text":"all feel a little bit better like the video if you liked it dislike it if you","speaker":null,"is_sponsor":0},{"start_s":449.12,"end_s":453.919,"text":"disliked it leave a comment letting me know did you learn something today is","speaker":null,"is_sponsor":0},{"start_s":452.4,"end_s":456.8,"text":"this something you already knew was it nice to have it validated anyway also","speaker":null,"is_sponsor":0},{"start_s":455.84,"end_s":462.72,"text":"check out the link in the video description you can support us by buying a cool t-shirt like this one giving us a","speaker":null,"is_sponsor":0},{"start_s":460.16,"end_s":465.919,"text":"monthly contribution or that other thing right changing your amazon bookmarks one","speaker":null,"is_sponsor":0},{"start_s":464.4,"end_s":470.08,"text":"with our affiliate code so we get a small kickback whenever you buy cpus or","speaker":null,"is_sponsor":0},{"start_s":468.08,"end_s":474.38,"text":"graphics cards or whatever else thanks again for watching and as always don't","speaker":null,"is_sponsor":0},{"start_s":471.68,"end_s":482.8,"text":"forget to subscribe","speaker":null,"is_sponsor":0},{"start_s":482.8,"end_s":484.879,"text":"you","speaker":null,"is_sponsor":0}],"full_text":"so the other day i was shopping for a state-of-the-art CPU for my gaming and productivity pc when i realized that Intel's latest 5820k and 5930k both have six processing cores with hyper threading both have 15 megs of cash they have a clock speed difference of only six percent and yet the difference in retail price is around 200 oh there's the gotcha the 5820k only has 28 pci express gen 3 lanes you know the electrical connections behind the slots that we use for graphics cards and other expansion cards compared to 40 on the 5930k what a strange way for Intel to differentiate its mid-tier 2011 3 CPU from its entry-level one Corsair gaming RGB keyboards feature precision cherry mx RGB key switches for 16.8 million color per key backlighting for virtually unlimited customization click now to learn more let's start with a brief explanation of what pci express or PCIe lanes are and what they're good for unlike previous expansion slots like agp and pci pci express has a physical size and an electrical operating mode that can be independent from each other power is provided by the pins near the key in the connector and the rest of the connector is used or not used to provide more or less bandwidth to the device that is plugged into it the more bandwidth the more lanes are said to be being used for communication the most common speeds are 1x 4x 8x and 16x so here's a cool fact the different bus width cards and slots are actually interoperable that means that installing a 1x card in a 16x slot is fine and you can even go the other way around in this video i cut out the back of a smaller slot and put a larger card into it all that happens is that both the slot and the card will now operate at the speed of the lowest link in the chain so that's what's going to happen if we plug our PCIe 16x graphics card into what appears to be a 16x slot but if the CPU in our system doesn't have enough pci express lanes to provide the full 16 lanes your motherboard manual will give you more specifics with a slot by slot breakdown of how it's going to work but basically it'll simply interface with your pc at a lower speed usually 8x well that sounds horrible Linus won't cutting the link speed to my graphics card in half tank its performance not necessarily we're on the third generation of pci express with each new generation doubling the theoretical speed of the previous one that means a modern gen 3 PCIe 16x slot can communicate four times faster than an original gen 1 16x slot or another way of thinking about this is that a gen 3 4x slot is equivalent to a gen 2 8x or a gen 1 16x slot but while we already know that from countless articles that exist on the topic in the past that no previous generation of 8x slot has bottlenecked a then modern high-end graphics card with x99's positioning as the high-performance platform of choice for enthusiasts and for gamers i think it's fair to say that folks may be running not just one but two or even more graphics cards at a time and this is where concerns start to arise especially given that AMD and i suspect also NVIDIA is starting to do more inter-card communication over pci express when running in crossfire and again i suspect sli versus relying on those dedicated connectors on the top of the cards so let's introduce the test to eliminate the variable of the slightly different clock speed of the two cpus and since overclocking k-series chips is so easy these days we're gonna run both processors at four gigahertz a very conservative overclock that anyone should be able to attain for the rest of the bench we've got a Gigabyte x99 gaming five four-way sli compatible motherboard with 16 gigs of ddr4 2400 megahertz memory from adata thanks to both of them for providing the hardware for the test bench we're going to be using four NVIDIA GeForce gtx 980 4gb graphics cards and we're going to be running all this off of course our ax 1500i power supply so that nothing melts during the benchmarking process and here are the numbers fraps was used to take average frame rates for each of our standard test runs and all games were run at 4k on pretty demanding settings to ensure that we were pushing the hardware as hard as possible as expected a single graphics card config is not affected in any way since it's running in 16x mode on either CPU but dual cards will be running at 8x8x on a 5820k and 16x16x so an effective doubling on a 5930k so i guess as much as it might be a little bit more counterintuitive they both ran the same so there you go in three-way sli both cpus have to give up at least one 16x slot but again the results are not really affected in any way beyond sort of your standard variance from one run to another and then finally in four-way sli we see oh actually there's a difference here as you may or may not have noticed our 28 lien CPU doesn't have any numbers for 4-way sli NVIDIA requires graphics cards to be plugged into an 8x slot at least for sli certification so only 40 lane cpus have support for this configuration however it should be noted that even at 4k the benefit of a fourth card is fairly small and three-way remains our recommended max config even if you feel the need to spend over a thousand dollars on a bunch of graphics cards to put in your system it should be noted that AMD does not have the same limitation for crossfire so you could run four graphics cards if you really wanted to in that case but our recommendation remains the same anyhow so that's the story or at least most of it for gamers anyway compared to the mainstream z97 platform where it should be noted that even the highest end cpus have a mere 16 lanes Intel's enthusiast x99 platform in general and the core i7 5820k CPU in particular is a great choice even for multi graphics card gamers if they want to reap the benefits of an extra two processing course ddr4 memory and higher overall memory capacity limits things do get a little bit dicey for non-gamers though when it comes to other pci expansions so make sure that you consult the manual of the motherboard you want before investing in this particular CPU because you may find that the m.2 high speed storage slots and in some cases even built on ports like SATA express and usb 3 headers might not work with too many pci express cards plugged in or even be available at all with a 28 lane CPU so if in doubt head over to the cpus and motherboard section of the Linus techtips.com forum where our helpful community will get you sorted out thanks for watching guys i hope this video put to rest some of the concerns about oh no the affordable one doesn't have enough pci express lanes i hope you all feel a little bit better like the video if you liked it dislike it if you disliked it leave a comment letting me know did you learn something today is this something you already knew was it nice to have it validated anyway also check out the link in the video description you can support us by buying a cool t-shirt like this one giving us a monthly contribution or that other thing right changing your amazon bookmarks one with our affiliate code so we get a small kickback whenever you buy cpus or graphics cards or whatever else thanks again for watching and as always don't forget to subscribe you"}