• Some users have recently had their accounts hijacked. It seems that the now defunct EVGA forums might have compromised your password there and seems many are using the same PW here. We would suggest you UPDATE YOUR PASSWORD and TURN ON 2FA for your account here to further secure it. None of the compromised accounts had 2FA turned on.
    Once you have enabled 2FA, your account will be updated soon to show a badge, letting other members know that you use 2FA to protect your account. This should be beneficial for everyone that uses FSFT.

Which runs hotter? GPU or CPU?

V

VX1

Limp Gawd
Joined
Mar 13, 2001
Messages
263
My water cooling setup is designed in a series. I decided not to do the whole Y fittings and extra tubing. I was not sure however which runs hotter, the GPU of an ATI 9700 Pro (stock speed) or the AMD XP CPU core running at 1.7v.

The diode from the mobo on this AT7-Max2 reads the CPU at 46 C. I have no idea how hot the GPU core runs though.

Which runs hotter? Reason being I would want the coolest running silicon in the series before the hottest running silicon.
 
I would say CPU only becuase the CPU is bound to draw more watts than the GPU, so it has to dissipate more (the only exception of recent note I think is the new 6800 ultra... that thing is insane). The temps you read on either isnt all the reliable since they both have a HSF on it, so it dissipates some of the heat already. not sure how well a series setup like that is gonna work though, cuz I have no experience with watercooling.
 
GPUs are probably the hottest running chips in your system. Anandtech showed numbers well into the 80s when they did a test on GPU temps.
 
The GPU is probably as hot or hotter when playing games, but the rest of the time the CPU will be hotter.
 
Well, CPUs can make upwards of 100 watts of heat, without overclocking, even.

GPUs are still in the 50s and 60s.
 
my 5900SE has a default setting to downclock once the core temperature breaks 110C... take that as you will.
 
The CPU uses more current, and overall dissapates more heat, but tempature wise, the GPU runs hotter, as it's dissapating the heat over a smaller area.
- anyway, GPU temps > CPU temps - but that also depends on what CPU and what GPU you are talking about too. Does a P4c get hotter than a TNT ? umm, yah. Does my 5700u get hotter than my 2500+, yah.

Peace,
Tim
 
Originally posted by somecallmeTim
The CPU uses more current, and overall dissapates more heat, but tempature wise, the GPU runs hotter, as it's dissapating the heat over a smaller area.
- anyway, GPU temps > CPU temps - but that also depends on what CPU and what GPU you are talking about too. Does a P4c get hotter than a TNT ? umm, yah. Does my 5700u get hotter than my 2500+, yah.

Peace,
Tim
Click to expand...

you are also not considering the cooling for each though. If you put the cooler on your 2500+ on your 5700u, the temps would be MUCH lower. If you put the cooler from your 5700u on your 2500+, it would die.
 
Yeah, if it's hotter due to running over a smaller area, then most likely that still means it's cooler since it's able to handle running over a smaller area, whereas you most certainly can't pull the little puny things like I've seen on video cards including the less than quarter thick heatsink I removed from mine with quite possibly the least effective (and smallest number of) fins I've ever seen and a tiny fan that probably pushes 3 cfm. d-: Put that on a P4 and underclock the heck out of it and you still probably couldn't get it to post, whereas you can pull off some passive cooling on a video card. This means the GPU is generating a LOT less heat with most video cards. (Of course, mine was made with a really small process and the only thing keeping it in production is it's extreme overclockability.)

Anyway, I assume the 9700 is cooler until proven otherwise.
 
it doesnt matter where it is in the loop


Thermal Equilibrium...


It is observed that a higher temperature object which is in contact with a lower temperature object will transfer heat to the lower temperature object. The objects will approach the same temperature, and in the absence of loss to other objects, they will then maintain a constant temperature. They are then said to be in thermal equilibrium.

-Zeroth Law of Thermodynamics


didnt type it it was cut and pasted but ya what ever
 
Yes, of course, but remember that first of all, this has moving water and, while that still applies to anything, because it's moving through that radiator and all that, it tends to get a little uneven. Also, if the material is a lower temperature, it will absorb more of that heat (put a dab of ice on you, then turn a compressed air can upside down and spray that and tell me which you notice more effect from -- I have a scar now, lol) at once, and we want to remove as much as fast as we can.
 
Assuming a flow rate of a gallon/minute (a pretty common rate) and a 100 watt heat load, the temperature of the water coming out of a waterblock will only be 0.4°C hotter than the water going in. Faster flow will give less difference, slow will give more; more heat, more difference, etc. etc.

Would you be able to notice if your CPU was 0.4°C hotter or cooler? Will 0.4°C limit your GPU's overclock? :) Use whatever order is easiest or looks best.
 
You must log in or register to reply here.
Back
Top