Kilzon

Well I may have found the answer to my heat problems. I reinstalled the HS with a very thin layer of AS5... Idle temp was 59°C! Took everything back apart.. and BAM! I noticed that the AS5 hadn't even contacted the center of the heat spreader on my processor. I took my processor out, and checked the heat spreader with a straight-edge. The center of the heat-spreader on my processor is lower than the edges. My XP90-C HS isn't sitting flush (only the edges of the heat-spreader touch the heatsink directly. The only way I get decent temps is if I use a good amount of AS5 to 'fill in' the center.

Now I feel like i'm up a creek with a processor that I can't cool! Does anyone have any suggestions on what I can do here?

CrimsonMango

either try lapping the XP-90C (some have warped bases due to the heat used to solder the heatpipes)

or if you're more daring and don't mind voiding your warranty, you can lap the IHS on your CPU (i have a FAQ under my old name "Sneaky" that shows you how to go about lapping the IHS of a processor)

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Kilzon

The IHS is in bad need of lapping. I went out in the shop at work (I work at a sheet metal fab shop) and worked on it for a few. No doubt this will help, can't wait to try it tonight.

Awesome info & FAQ. Thanks a million!

Kilzon

Spent all night sanding the IHS and HS base.... Put all back together with thin layer of AS5... load temp is 62°C @ 3.825Ghz o/c, 1.475 Vcore. Still seems high, very annoying. I've installed & uninstalled this HS about 15 or more times now in the last two weeks, heh.

Have those babies sanded smooth too, dangit. Not sure what the deal is... Two weeks ago had a 45°C load temp on the old P5LD2 board o/c'd with two Primes running. Using P5WD2-Premium board now but shouldn't make a difference in cooling since they are very similar layout.

Let me ask another question...

How 'thin' should a 'thin layer of AS5' be? Should it be just thick enough to cover the IHS completely so I can't see any of the copper through it? Or is that too much?

Taeric

Unfortunately, smooth does not necessary equate to flat. A nice mirror finish can be achieved on a concave or convex surface. The gear at your shop might have made this point moot; it's more of a reminder to folks to lap by hand.

In theory, the AS5 should be applied only at the microscopic level. If you read their documentation, you're supposed to apply it and then wipe it off so it only fills in the microscopic nooks and crannies on the IHS and heatsink. Using that method, about all you see is a dirty or greasy residue where you applied the AS5. Of course, that only works if both surfaces are flat. The preferred method on here seems to be applying a small (smaller than a piece of rice) drop to the IHS, placing the HS on the IHS, twisting both directions to spread, and engaging the retention device on the HS. With this method, you'll get a little more than a greasy splotch, but it will still be a fairly small amount. As good as AS5 is, too much can hinder proper cooling.

I'm not sure what to suggest to you at this point, especially if the issue is in the IHS. There is a FAQ or two on here on how to remove the IHS, though I'm not sure I would attempt that on a LGA CPU.

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Kilzon

I just followed the lapping FAQ... I got some sandpaper and used a thick piece of new glass as a surface. Checked it with a straight-edge when I was done and it was flat.. at least as flat as I could tell with my eyes. Only other thing I can try is to polish it with finer grit sandpaper so that I get close to a mirror finish. I think the finest grit I used last night was 1000 grit, but the HS base felt smoother to the touch when I was done than it did out of the box.

Only dang thing I know of is to stick a Tornado on it, and to get higher CFM case fans. But I'd rather my rig not sound like a 747 taking off, lol...

Is it possible than the HS has been damaged? Maybe the heat pipes have separated from the HS base somehow. It seems in perfect condition though.

PaulB

yeah those temps are still way to high for stock settings... Do you maybe still have the stock HSF that came with the cpu? give it a try and see if there is any improvement. Course the stocker sux but should have you around 45 to 55C on load if not a good bit lower. Sure could be that the heat tubes have something wrong with them.

CrimsonMango

are you positive that the LGA775 adapter for your heatsink is mounted down securely? the LGA775 mounting can be a real PITA at times, so you might wanna check that its secured down properly


if idle temps went up along with load temps with your board switch, then it may actually just be the sensors, which have up to a +/- 10* accuracy range at times

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Kilzon

Ok. I re-installed the stock Intel cooler. I am overclocked to 3.8Ghz. Vcore is 1.4625. Highest load temp is about 64°C. Highest load temp with the XP90-C was 62°C.

Now this is really making me wonder. I'm going to reapply AS5 to the stock cooler tonight again and double-check the temp with the stock cooler.

On a brighter note... I installed my Zalman ZF700-Cu on my 6600GT today and checked it out. Man that thing is sweet, got a load temp of 53°C after running 3dMark2001 in 1600 x 1200, overclocked to 575/1150! It dropped my VGA temp by over 20° over the reference cooler on my PNY. Sweet.

That also makes me feel better that I am using AS5 correctly on my processor

Once I recheck temp with stock cooler tonight, gonna reinstall the XP90-C and just assume it's the sensor if temps are still a little high.

Kilzon

Thinking that it's the XP-90C thats causing the problem. I re-installed the stock HS... Temps are only about 3°C higher with the stock HS. Load temp is 64°C with the stock cooler, and 61°C with the XP-90C.

Got it from HeatsinkFactory.com... Gonna try to send it back and exchange it for another one, dunno if they will do it though.