9800 pro water cooled???

hi just wondering about whether i have attatched my water cooling block correctly...i am using asetek vga cooling block on a ATI (manufacturer) 9800 pro ...whilst fitting the cooling block i looked at the core and it all seemed level with the surrounding shim...all put back together after a minor leak and all systems go....so far so good....HOWEVER ....on closer inspection of the standard heatsink the part in contact with the core is slightly raised do i need to remove the shim from the core????? i am a bit worried about overclocking it just yet until i know ....thanks in advance

The 9700 Pro had a "chewing gum" Tim to fill any gap which was a poor way to do it. The 9800 I have like yours has a core sized step in the centre of the heatsink to ensure good contact with the core using a thermal paste.

This will have "sorted" the previous tim/contact problem, but also renders the shim pretty pointless, and indicates to me that they, (ATI), still think shim height / use of the tim is a possible problem area or there would be no need for the raised core section on the sink base, (about 0.3mm). This also wont change the fact any flat bottomed block may not contact the core well, (or at all), if the shim is proud on some examples, due to mass production & quality control factors. On both of my cards, 9700/9800 the core was significantly lower than the shim.

You can of course remove the shim, some people will tell you it's easy, and it is, but there is a danger of killing the card, as some have done. I never recommend modifying 3D cards permanently if there are other ways around it, I milled a similar relief to the waterblock base.

thanks bladerunner i made sure i looked across the shim and core and both seemed level but have since found out there is a danger of damaging the resistors placed around the core so will leave it as i is...i lit the card up a bit yesterday but will wait until i get a heat sensor before i take it any higher...if anyone knows temps that are dangerous on these please post!! i raised the core to 432 mhz and memory 362.5 mhz both seemed fine on 3Dmark 01 & 03 i have noticed te core on these have been taken alot higher (near 500!) will be taking things so slow while i burn it in a bit i think