Thermal Pads for GPU HSF - Help wanted

I am looking at getting my hands on some thermal pads for a couple of GPUs but was hoping to get some advice/experience.

On my 1950pro there is a thin grey non sticky sheet thats about 0.5mm thick. The PCB has slightly warped away at the back of the card causeing a slight gap between where the hsf should touch the VRMs conducting through the thermal pad.
I have added a small piece of copper sheet and thermal compound (on each side of the copper sheet) to help insulate but in doing so have probably insulated the vrm as there are now 5 material interfaces!
The VRMs are overheating as soon as the card hits load; its fine in 2D and worked when the VRM area has clamped shut.

Would people use the sticky sheets or just pads?

My second is for a 8800gtx. do they sell replacement pads and what type are present origionally.

Hope that makes sense and look forward to your responses.

most use toms shop (chilled pc)

http://www.chilledpc.co.uk/shop/inde...faf9a0c38ddae8

uses 1st class post so the price is excellent with postage :)

you can get a few sizes to see what the best fit is

generally speaking, if the heatsink is mounted using screws or bolts then you should use non-sticky thermal pads, as you have noticed the PCB may warp after prolonged use. Usually the bowing starts at the GPU core area and bow again at the VRM area depending on how hot your card is.

Anyway, you will want as little interface as possible, just heatsink|TIM|heatsource. Might get tricky in your situation, thermal pads come in different thickness, generally aim for 1mm thicker than you need, it'll squash a little bit to fit.

also +1 for chilledPCs for good retailer that I've used several times in the past

When i removed and replaced the cooler on my ol 7900GTX i used the Akasa Thermal Pad sheet that you can get in Maplin - http://www.maplin.co.uk/Module.aspx?ModuleNo=221326

Not used ChilledPc before, but Maplin might come in handy if you cant wait for ChilledPC to Deliver.

The Akasa stuff is also availible from scan, ebuyer and most other e-tailers
The thermal pads Chilledpc sell, have the advantage of coming in different thicknesses so you can get the correct thickness.

The gaps between the HSF is about 1mm on the 1950pro.

Chilled PC is not bad value at all. 17cm2 for three pounds is better than I can find on ebay which is about £2 for 9cm2 from a nice man in HK.

I'll avoid the sticky stuff which is a bit on the thin side.

Lucky, Is the 1mm rule from experience, is there a good guide somewhere? I know the size of the gaps and would like to get this 'right first time'.

Thanks again! If anyone has anything to add; please post.

thicker than needed is better as it does compress very well

the 1mm stuff under my water blocks compresses to less than .5mm when the blocks bolted onto it.

Thermal pads from 3m either have a silicon or crylic based center. the acrylic one are only really rated upto 100C and the silicon upto 150C from what I remember seeing on the specs sheet.

The VRMs on my x1950pro are running at 124-125C and crash as soon as its stressed. I need the silicon based ones I reckon.

I've emailed ChilledPC to see if they'll give me the part number, will see what they say.

There is suprisingly little information out there.