HD 4850 New Cooling = Crashes

Quikfeet

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Aug 14, 2008
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Hey all--

I just put on some new Arctic Cooling S1 Rev2's on my HD 4850's. The cooling is superb, but since installing, I find that occasionally in games the whole screen locks up, the sound seems to hang (repeats the last sound it was doing before crash), and the computer has to be restarted.

I heard that this may be caused by putting heatsinks on the Voltage Regulators? on the far side of the card, is this what's happening?
 

Quikfeet

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Aug 14, 2008
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The coolers didn't come with enough heatsinks, so about 1/2 of my voltage regulators are covered. I have heard people having problems if they are covered, but also people having problems if they aren't.
 

jennyh

Splendid


Well by covering half of them you've guaranteed a problem. :D

Have you overclocked the card?
 
1) Since you appear to have two cards you should run one at a time to isolate the problem card (though it may be both). i would have kept the stock cooling on one first

2) ensure you have two 120mm case fans. They can be low-flow but without knowing your setup it may be possible it's a heat buildup in this case. If I had an Antec 300 case I'd put super low-flow fan on the side panel and one at the top.

3) can you monitor your GPU temperature(s)

I can't figure you how you connected this in Crossfire. I guess you have both with just the passive heatsink and this may be your problem.

One solution for motherboard that support this (often Tri or Quad boards) is to use the 1st and 3rd slot so you can add the 120mm fan to each and use the Crossfire extension bridge.

If your cards run fine separtely it's almost certainly a heat buildup by having these two cards next to each other with not enough air flow. So you need to create air flow somehow.

(If you have the space, at least attach a 120mm fan to the bottom card)

Passive cooling sounds great but something (a fan) needs to move out that heat from the case. Try to visualize the air flow in your case for setting up fans but also remember that it's that REGION of heat buildup you need to address most.
 

Quikfeet

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1) I have isolated the problem to the bottom card. It seems to crash randomly, red light indicating either overheating(which i doubt), or a voltage error.

2) My case is frosty. My GPU's are frosty. My CPU is frosty. Heating isn't the problem. The GPU's run idle at about 40C, and highest I have seen them on the new cooler is 58C. The passive coolers on them have a 120mm fan on them as well.

3) Yep. Refer to the above.



To connect it in crossfire just required a little jury-rigging. Like I said, heating can't be the issue here as the case is extremely cool, and so are all the components inside them. The top card runs fine separately, it's the bottom card that is having the issue, and I swear it has something to do with the VRM cooling.

I moved the heatsinks off of the inductors to place on the VRM instead, which seemed to help the top one, but the bottom one still seems to be freaking out. I cant seem to justify removing the heatsinks, so I suppose I should try the old hacksaw method to get the old sinks on them?
 

Quikfeet

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Aug 14, 2008
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I did some more work today, and just found that the voltage regulators are getting too hot on that card, even with the heatsinks on them, so I am going to try the hacksaw method or order a seperate heatsink for them. Thanks for the help.