Can You Judge a CPU Cooler by its WEIGHT?
Linus Tech Tips
·Linus Tech Tips
·2018-05-06
·
1,058 words · ~5 min read
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so the conventional wisdom at least used to be that when you were shopping for a
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power supply you could basically judge the quality by the weight
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the heavier the power supply the better it probably was
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that is until some cheapo manufacturers started literally putting hunks of metal
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in them to make them seem better that got us thinking
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what about hunks of metal could you literally walk down the cooling aisle
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with a luggage scale and buy the heatsink with the best price to weight
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ratio to cool your CPU
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maybe
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g skills km780r mechanical keyboard features a brushed aluminum top plate on
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the fly macro recording and various cherry mx keyswitch configurations learn
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more at the link below we know
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more weight or mass if you want to be pedantic about it does not mean better
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cooling a two kilogram block of aluminum
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on top of a CPU would weigh a lot but
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wouldn't do a good job of cooling it down
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for long so what you're actually after
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when it comes to dissipating heat is
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surface area the more surface area that you have the more cooling will be
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available so then if we assume that most
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commercial CPU coolers are designed by mechanical engineers and not by
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chimpanzees and that most companies are
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interested in saving cost while optimizing performance then it would
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make sense that most heat sinks out there represent the manufacturer's best
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efforts to strike a balance between material cost and heat dissipation
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so assuming that everyone has done their homework equally the heavier the cooler
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the higher the performance should be but
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as we know so very well around here not
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all engineering is equal so we grabbed a
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bunch of coolers off the shelf and devised a test the weight of each cooler
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was recorded with the fan but without
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mounting hardware we kept the room at a consistent 24 degrees celsius and set
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the fan curve to full speed on our system for all of our tests the CPU we
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used was a core i7 7700k with the ida 64
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fpu test running for 30 minutes before the average package temp was taken for
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the next five and looking at the results there are actually some very interesting
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takeaways here first of all the nhd50 outperformance of
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every aio liquid cooler is a great testament to how well engineered it is
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and while we're praising strong products for
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their efficiency Corsair's dual 140
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millimeter aio outperforms the thermaltake triple 120
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aio which has worse case compatibility
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if i had to hazard a guess here though i'd say that this is down to the similar
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surface area of these two layouts and the design of the fans the most striking
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thing about these results though is that after a weight of about 400 grams the
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heat transfer to weight ratio
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plummets with the coolers that remove the most heat per gram being the
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lightest ones why is this
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well getting finally into the purpose of
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making this video to let alex nerd out for a bit it's actually because of a
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design concept called the infinite fin approximation basically for a fin of
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similar thickness material and airflow
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it can only get so long that is to say the distance from the
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heat source before adding more material is basically a waste this concept is
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illustrated using this graph where the y-axis represents heat flow
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one would be all of it and zero would be none
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so for an infinitely small fin you would dissipate zero heat that makes sense and
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for a mile long fin i mean by the tip of
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it practically all of the heat from the source would have been dissipated to the
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air before it could possibly be conducted there
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that is why in the early 2000s CPU
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coolers transitioned from thin or flower
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based designs to the heat pipe ones of the late 2000s and the liquid cooling
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designs that are common today so newer cpus generated more heat but
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they didn't get any bigger so there was no point in making the fins
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longer which means that these new high conductivity fluid based mediums
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heat pipes and water helped solve the challenge of moving the heat away to
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length optimized fins elsewhere
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is this something that we can show happening in real life
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actually yes the easiest way is by using this flear
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one thermal camera looking at the Noctua nhu12s
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the ends of the fins come in at about 38 degrees celsius
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14 degrees above the temperature of the room whereas on the massive
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nhd15 the fins are only about 31 degrees
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celsius and remember the lower the
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difference in temperature the slower the heat transfer
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so with a given heat load these longer fins
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are cooler and therefore are dissipating
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less heat per amount of material
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bringing us then finally back to our original question
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can you judge a cooler's performance by
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its weight well actually it turns out you kind of
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can surely there are some exceptions out
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there and some did better than others but everything we tested seems to have
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had some engineering thought put into it so that's good to know
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we are working with rosewill to give away nine that's right nine of their
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nebulous series gaming headphones they've got the gx10 gx30 and gx50
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models the gx10 features leatherette earcup cushions bright blue led
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backlighting around the earcups and compatibility with most devices not to
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mention a 25 price tag while the gx30
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and 50 both have detachable microphones as well as RGB lighting but the gx 50
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has 7.1 virtual surround so the gx30 is
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35 and the gx50 is 45 to purchase at the
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links below oh and also linked below is the link for the giveaway nine
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chances to win go check it out
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thanks for watching guys if this video sucked you know what to do but if it was
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awesome get subscribed hit that like button or check out the link to where to
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buy a cooler in the video description also down there is our merch store which
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has cool shirts like this one and our community forum which you should totally
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join