Radeon 5970 Overclocking: The VRM Temperature Bottleneck @ AnandTech
 

AnandTech

So it seems that the 5970 can clock even higher if the VRM temperatures can be lowered. That thing must put out a ton of heat.

Doesn't help that each core in the 5970 doesn't come with "full" VRM banks making each individual phase work harder.

good thing ill just be gaming on mine then XD

Doin some testing on mine today and noticed Crysis studdering from time to time. I did a furmark test and sure enough, my GPU1 throttles back after a few minutes.

Looks like its time to watercool.

This could also be by Far Cry 2 shows somewhat lackluster performance results.

Oh, and its not only overclocking: people are being held back @ stock clocks / voltage as well.

Seems that the stock cooler isn't do its job very well, despite it having a vapour chamber in there. And here some thought the 5970 wasn't doing too well cus of crappy drivers.

The problem seems to be that the GPU1 VRMs aren't actually being cooled by the vapour chamber. The GPU2 VRMs are being cooled by it and have much lower temps.

The cooler does its job just fine, its the second set of VRM's that aren't even connected to the main heatsink assembly thats the issue.

Kind of a silly oversight in my mind.

Well I did a little testing and its only one card
GPU 1 and 2 5970
GPU 3 285GTX

Max temp on core with extreme burning mode was 80.5 C
Max temp on Vram was 99C extreme burning mode can do upto 120 before it effects anything.

Now this is my card and how it runs on extreme burning mode.
My advice turn up fan speed and for any gamer this will not be an issue.



Heres the screen shots.
http://img687.imageshack.us/img687/474/myth2.jpg


link to higher quality screen
http://img28.imageshack.us/img28/474/myth2.th.jpg

So many conflicting reports on the whole downclock/won't oc "well" thing =\ . Perhaps water is the way to go on these things.