Aftermarket cooling - cheating the numbers?

EvilBob

Member
Jun 25, 2008
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Here's a question for you: Do aftermarket coolers that only contact the GPU cheat in delivering "low" temps?

I have a 3850 agp - with the stock cooler, idle was usually high50-low60C, load high60s or so. I replaced the stock cooler with the accelero S1, new thermal paste, and the matching accelero dual fans on the heatsink. Idle dropped to low-30sC, load high30s-low40s - awesome results!

But here's the rub - the accelero only contacts the GPU. The memory chips now have their individual heatsinks, and my power converter gets nothing (some cards fit the heat spreader, but not mine).

Now, the massive copper plate that is the stock sink contacts the GPU, memory, and power converter. So the GPU thermal sensor, which is reporting all of these temp numbers, could see thermal bleed across the sink from the memory and power converter. With the aftermarket cooler, all of these heat loads are now disconnected, so the GPU sensor only sees GPU heat.

There's the root of my question - in getting excited with a 20-30C GPU temp drop with the aftermarket cooler, is my head in the sand to the fact that the memory and power converter heat load is still there, but just isn't observable?

TY! --EB

ps ya, I did post this first to the end of the 4850 temperature discussion - sorry, that was out of place.
 

Zap

Elite Member
Oct 13, 1999
22,377
2
81
Hello EvilBob, and welcome to the forums.

You pose an interesting thought which may affect quite a few aftermarket coolers. The thing is that aftermarket units are often made as somewhat "universal" meaning the manufacturers want to make a single product work with as many video cards as possible (for lower manufacturing and design costs). Of course this does cause some tradeoffs. Sure, the GPU itself may be running cooler, however other components may be running HOTTER than before. Of course your thought on other components not heating up the GPU is interesting, but I'm not sure how it can be measured.

In any case, I think the best solution will be one tailor-made for a particular card. For instance, BITD Arctic Cooling made probably over a dozen "Freezer" products for various Nvidia and ATI GPUs, and these would have a plate that contacts the RAM for cooling as well as the GPU. This kind of design is rare these days, so perhaps it may be better to look for video cards that come from the manufacturer with better-than-stock cooling, as those would be designed around a particular card.
 

BassBomb

Diamond Member
Nov 25, 2005
8,396
1
81
Typically temperature monitors for the chips are on die, so you won't see the actual increase that is occuring on the RAM/Mosfets

I wish they still had ambient monitor like on the 6800's
 

Zap

Elite Member
Oct 13, 1999
22,377
2
81
Originally posted by: BassBomb
I wish they still had ambient monitor like on the 6800's

I think the new GTX 260/280 cards have separate ambient monitors. I recall seeing them in Vista with the new Nvidia System Monitor tool, not the Ntune version but the new one that replaced it in the NVIDIA System Tools with ESA Support. Unfortunately I do not know where on the card this ambient temperature is measured. Perhaps I can find out from Nvidia.
 

Cutthroat

Golden Member
Apr 13, 2002
1,104
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Everest reports an ambient temp for my 8800GTX. I have no idea where it is measured, but it seems to be accurate.

I get 3 GPU temp readings from Everest:

GPU: 70
GPU Diode: 77
GPU Ambient: 58