D Tek Uni-Sink into Tri-Sink: How to improve your VRM temps/contact.

[Diverge]

I got tired of my 280 gtx's VRMS hitting such high temps (85-90 while gaming). So I decided to pull my videocard and see what I could do about it. I unscrewed the block from the card, leaving the water cooling system intact, and proceeded to take off the Un-Sink to see how those thermal pads were looking.

What I noticed was the one pad that covered the chip, was intended a lot. The memory chips pads were slightly intended. And the vrms pads had no intends, to very little... looking like they weren't making too good of contact.

So as I was looking at the heat sink, trying to think how I can make it have better contact I noticed how the screw holes were positioned; that I could cut the heatsink in 3 separate parts, one part for each section (that chip, the ram, and the vrms).

So I used a hacksaw to cut it nicely into 3 parts. The blade fit nicely between the prongs of the heat sink, making it very easy to cut perfectly straight lines.

I didn't take any pics, but this is basically how i cut the heatsink:


This allowed me to do away with the thermal pads, and use thermal paste instead; as the 3 different sections of the card (ram, that chip, and vrms) are at different heights... but with the heatsink in sections now, I was able to use paste since each section sat flush.

Since the vrm section is separate now; I did some further modding to the vrm section, putting paste on, pulling sink off, see how they made contacts. There's basicall 3 rows of vrms, 3, 3, 1. On my card, the 3 front, and 1 on the back made good contact, while the middle row wasn't too good. So I took out a nice flat file, and adjusted the 3 front, and 1 end, along with the built in stand offs until I got everything nice.

before, if i used the OCCT gpu test, my vrms would hit over 100 in like 45 seconds. Now it takes over 5 minutes to reach 100, and climbs there very slowing. And I can feel the vrm section of the sink, it's pretty damn hot!... but now that is is independent, it's not heating my ram chips to such high temps anymore

[millertime359]

You have any air circulation around your video card? I noticed my 260 got toasty when I didn't have a fan blowing on it.

[Diverge]

You have any air circulation around your video card? I noticed my 260 got toasty when I didn't have a fan blowing on it.

Yeah, i have 3 yate loon meduims set to full blast blowing on it.. but they are pulling air through my rad. But that air is a lot lower temp then the vrms, probably lower then the vrms idle at lol.

the card is overclocked a good amount though, and it runs at 1920 x 1200 when i game.

[Diverge]

Even though I lowered my vrm temps, I still had some problems.

Today while gaming, I noticed my vrms where over 100degC, and my game kept studdering badly... looking at the current draw in GPU-Z, it was drawing about 107 amps too.

So I thought it seemed like it was either unstable, cause of the heat, and current it was drawing, or maybe the voltage it was at was intermittently unstable at certain conditions. So for the hell of it I bumped my vcore from 1.18875V to 1.20V. Figuring it will either make it stable, if my card was unstable do to lack of volts, or it would make it run hotter, and draw even more current.

Now i'm gaming @ < 75deg C, and only drawing less the 74 amps max so far

[millertime359]

Seems there wasn't much of a reason to cut the uni-sink then?

[Diverge]

Seems there wasn't much of a reason to cut the uni-sink then?

well it lowered my temps, cause I did away with thermal pads. and the vrms aren't heating the whole heatsink up anymore, just the part connected to the vrms.

[millertime359]

well it lowered my temps, cause I did away with thermal pads. and the vrms aren't heating the whole heatsink up anymore, just the part connected to the vrms.

It just seemed part of the temp issue was coming for the voltage issue.

I see your point though.

[RoadconeTuning]

well if you cut it off then why not use some of those little enzotech copper heatsinks, i'd think they'd do fine w/ a little airflow