Hot GF4 4200

[SleepWalker]

Hi All.

I'm running some watercooling on my GeForce 4 4200 card (GPU overclocked to 310 mHz) and even though the copper waterblock (homemade) is nice and cool to the touch the temperature on the backside of the card is still about 50 degrees centigrade (45-48 idle, 50-51 load)

A nice graphic description of the setup:
_ _
--------- Metal bar
wwTww Cork pads and temp probe
------------------------------ Graphics card
|*****|
|*****| * copper head
|*****| | Screws
----------- Metal bar
- -

The block is screwed on nice and tight and the entire surface of the GPU is covered in a thin layer of ASII
When i take the block off i can see that the block has touched the entire GPU.

Now my question (sorry about the long windedness):
Am i doing something completely wrong to get that high a temp on the backside of the card, or is that just the nature of them damn chards? .. Is the anything i can do besides using a TEC?

regards

 

[error_911]

well actually you can always put a fan blowing away from the card on its underside, that'll cool it down... but your temps to start with aren't terrible, I mean its a lil hot but not that bad, especially for an overclocked GPU. Another solution I discovered a lil while ago is to pick up some of the paste that Innovatek uses when mounting their hard drive coolers.. you can always put some on the back of the vid card and then put the copper plate behind it - it will allow the heat to transfer unlike the cork... you can even put a bigger plate to dissipate more heat, or make a back-side waterblock ... anyways, this is the <A HREF="http://www.sharkacorp.com/cgi-bin/TLSstore.cgi?user_action=detail&catalogno=kl-wc-hdc2-a01" target="_new">paste</A>

<b>people are only idiots when they don't realize - when they do it just gets funnier, like a dog chasing its own tail, or like george bush's public address(es)</b>

 

[SleepWalker]

Ah, thanx for the advice. I think il'l stick with what i've got now, since i don't think il'l be able to overclock it much more anyway. And besides it's mostly the slow RAM that's hurting it now.
Perhaps when i get a faster card il'l go for some more extreme cooling.

 

[lhgpoobaa]

no... the backside of the card is allways hot as its very close to the GPU core... thats why some high powered graphics cards have a heatsink on the back as well.

Dont be worried though... GPU cores naturally run hot.

<b>When life hands you lemons, ask for a bottle of tequila and salt</b>
<A HREF="http://members.iinet.net.au/~lhgpoobaa/images" target="_new">My Images!</A>

 

[Teq]

Please don't take this as a criticism of your work, it's not meant that way...

The key words in your message might well be "home made".

Thermal design is a strange and confusing business. Designing a heatsink (in this case a waterblock) that does a really good job is not as simple as drilling a few holes in copper. Distribution of water to get even cooling across the entire cooled object is very important as is turbulance inside the waterblock itself. If the water is just running, nice and smooth through a tube (or drill hole) in the block it's likely it won't take off much heat at all. The water needs to distribute itself evenly over the entire surface of the cooled object (inside the block, of course) with some turbulance to make sure ALL the water going through gets into contact with the hot surface of the block. The block needs to have sufficent mass to absorbe all the heat from the cooled object. You also need enough turbulent waterflow to take that heat out of the block.

Tricky stuff.

One of my concerns if the block is nice and cool but the chip is still running hot, would be that the device isn't drawing enough heat from the cooled object. If the chip is hot or there is still a lot of heat in the area I'd be worried that I wasn't getting adequate cooling effect from my device. (And yes, I've scrapped a lot of self-designed stuff over the years...)

Can you measure the core temperature of the GPU itself?
Have you tested the thermal resistence of this waterblock you made?

Also, the other responders have a point... some GPUs run blistering hot and don't seem to mind. Heat isn't directional, unless you direct it, and the back of GPU cards do get hot.




--->It ain't better if it don't work<---

 

[SleepWalker]

Good points. I think that the heat produces by the GPU is well within what the block can remove. Since I know that the block in good contact with the GPU and the block isn't warm (no temperature difference can be felt between the block and the case sides) i was just wondering if perhaps the heat spreader on the GF 4200 is a far cry from optimal or something, hehe... I think that the sughestion with the non electrically cunductive thermal grease and another block on top would be good, though i don't know how much heat can actually be removed through the PCB. Will need to experiment some more (Experimenting and ruining stuff is a good excuise for upgrading )