AIO temperatures are lying to you it's true but allow me to explain let's pretend a guy
named andy has been sporting a cooler master hyper 212 EVO for the past year he's satisfied
with this 4.7 gigahertz i7 700k temperatures but wants to push the overclock a bit higher
right now his core temperatures idle at around 30 c and things jump up to around 80 degrees celsius
immediately after starting ida 64. still not bad for a run-of-the-mill air cooler but things could
definitely be better andy realizes this hops online and decides to purchase an AIO like this
one here the deep cool captain 240ex just insert your AIO liquid cooler of choice these coolers
use liquid let's assume water with a few additives that's usually what it is as a medium of exchange
between cpus and the outside world the water isn't making direct contact with the cpu there's usually
nickel plated copper or an aluminum base of sorts sandwiched in between but nonetheless it's the
water that ultimately transfers heat away from the source and then comes the radiator these vary in
size and fin density but essentially reverse the process that occurs at the block instead of heat
being transferred from metal to water the radiator transfers heat from water to metal and relies on
installed fans to dissipate or radiate heat into the atmosphere but here's where the lie begins
andy removes his hyper 212 evo installs the aio let's assume a constant max pump speed
and a normal fan curve and immediately checks idle temperatures much lower right let's say
23-24 degrees celsius wouldn't make much sense for core temps to be lower than room temperatures andy
then runs itis-64 and notices that his immediate temperature jumps are much more controlled
whereas his core temperatures jumped to 80 degrees celsius before they're only jumping to around 55
degrees celsius now job well done right the aio was definitely worth it well let's see
if he's still saying that in about an hour or so in comes the misleading nature of aios and comes
specific heat it's defined as the amount of energy required to raise the temperature of a substance
by a single degree celsius or kelvin it is often listed as an intensive property with respect to
mass hence joules per gram kelvin or joules per kilogram kelvin if we assume a copper cooling
system and a perfect translation of energy from the cpu heat spreader to the cooler's base that's
what thermal glue seeks to do then the cooler in question would be able to absorb only 0.4 joules
of energy per gram of copper before increasing in temperature by a single degree celsius so in a
nutshell copper heats up very fast it's a thermal conductor and most metals behave in this way this
is why andy sees an immediate temperature jump with his air cooler when he first starts it 64.
copper is absorbing energy at the same rate that water would be in its place but copper has a
much lower heat capacity which means it heats up quicker it's absorbing a certain amount of
joules per second denoted as watts which is where tdp comes into play and is either passively or
actively radiating this heat water on the contrary has a very high specific heat capacity which means
that it can absorb a substantial amount of energy per unit mass before increasing in temperature by
a single degree its specific heat capacity is 4.2 joules per gram kelvin nearly 10 times that of
coppers as a relational example picture a stove with a pot of water if the pot is made of metal
usually a sort of stainless steel teflon combo the metal will heat up at a much quicker rate than the
water will not only because the metal is in direct contact with the stove but because its specific
heat capacity is much lower your cookware reaches water's boiling point long before the water itself
does even though it's in direct contact with the metal if both the water and alloy had the
same heat capacity they'd heat up at the same rate and reach water's boiling point at the same time
water's high heat capacity and low viscosity make it an excellent coolant in several applications
including pcs however ironic that may be but do not be fooled there are several misleading
claims on forums and even other youtube channels in regard to aios and their ultra cool yields
the first has to do with load testing when andy first started ida 64 the aio's temperature spike
was much more controlled if you recall 55 degrees celsius versus 80 degrees celsius but this isn't
the entire story the entire story would reveal the thermal property differences between water
and the metal in question usually copper or aluminum first off andy's initial temperature
spikes were lower because water requires nearly 10 times the energy to reach the same temperature as
the copper in the air cooler not only that but the entire loop requires a length of time to equalize
i demonstrated this with heisenberg's i7 6700k and the nzxt kraken x62 it took nearly 42 minutes for
the core temperatures to stabilize much longer than a typical air cooler whose respective core
temps would plateau much sooner you can verify this yourself if you have your own air cooler
in your pc doesn't matter what size it is your temperatures will peak within a few
minutes or so now this isn't to say that aios are unnecessary that's not the point of this video
of course this aio from deepcool will better cool your cpu than a hyper 212 evo hands down it does
a better job of dissipating heat plain and simple but not only thanks to the water involved also the
240 millimeter radiator further down the loop what i am trying to say is that aios are often
misunderstood because their testers are often too impatient to wait for temperatures to stabilize
at least those who are posting on forums all the time that their temperatures drop by 40 degrees
celsius which is usually not the case if you let those things run for a couple hours with ida 64
you'll find that that delta is much smaller i was watching a video from joker productions a few days
ago he built a sweet new pc and was discussing cpu temperatures after running ida 64 for just
over an hour he said on his 7700k captain 240 ex combo his core temperatures leveled off at around
75 degrees celsius that's what i want to hear he let the thing run for more than just a few minutes
one hundred percent necessary for liquid cooled systems the t delta can be much lower for air
cooled systems because metals heat up rapidly by contrast but in comes the other side effect
of aios the fact that they stay hotter for longer after prolonged burn-ins even if all andy does is
play video games for a few hours at a time they don't even have to be cpu intensive his core
temperatures will be higher for a much longer time after returning to an idle state because water
tends to retain heat much longer than most metals do thermal diffusivity is a variable at play here
of which specific heat is a function but without using numbers you can test this yourself as well
if you heat up an equivalent mass of both iron and water to the same temperature let's say 80 degrees
celsius and then set each aside to passively cool the iron will reach room temperature again much
faster than the water so while water requires more energy to reach a certain temperature
it also wants to hold on to that temperature for a longer amount of time which means that
your idle cpu temperatures could be in the 40s or 50s long after you've finished gaming
running benchmarks or rendering this isn't necessarily a bad thing it's just a side effect
of an aio you can't tweak fan curves to speed up this process by the way it is something to keep
in mind though as it's often overlooked by time users of closed and even custom loop assemblies
blue sky will also have this problem but not to any significant degree thanks to its two large
radiators you can't change the properties of the compounds but you can change the environments in
which the compounds react if you like this video be sure to give it a thumbs up thumbs down for the
opposite be sure to click the subscribe button if you haven't already i will catch you in the next
video waiting to finish good old blue sky this is salazar studio thanks for learning with us
you