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View Full Version : Taming a Prescott for SETI


thecondor
02-23-04, 03:04 PM
There are plenty of reports about the heat producing properties of the Intel Prescott processor. Be that as it may, I wanted one to experiment with, especially SETI performance, and got one of the 2.8e’s from New Egg. When it arrived, I hurriedly slapped it in, booted up, started SETI and watched my temperature monitor soar to 82 deg. C. I quickly shutdown and gave the situation some thought. This has got to be manageable, and sure enough, it is….even on air.
The first thing I did was take off my SLK 900 U and replaced the tab clamps with the
screws and compressible springs. I then lapped both the heat sink and CPU surfaces to a good mirror finish, applied new Arctic Silver 5 and assembled everything back onto the Motherboard. This is a dual channel MSI 875 Neo2, which comes with heat sinks already on the power regulation MOSFET’s.
The second thing I did was to reconsider the 92 mm fan. I had always thought the center was too big and the overhang too much to be really effective, however it worked just fine on the 2.6c. What I did was really counterintuitive. I decided to use a YS Tech 70mm TMD type fan. The overhang is small and the flow is not masked by a large center motor.
Finally, I enlarged the side opening on my case to accept a 120mm Vantec Stealth. This fan puts out 53 cfm and is very quiet. I have no other case fans except what is on the Enermax dual fan power supply.
Here are my current results. From the original 61/82 deg idle/load, I now have a very manageable 40/57 deg. In addition, this is all on air and is just as quiet as it always has been. The temps may drop a little as the AS5 works in. The SETI performance is much as TC has described without the water-cooling hassle. I get 22 wu per day at 3290 mhz and 24 per day at 3500 mhz. The 3500 mhz is at 250 fsb and puts the Adata Vitesta PC4000 right on spec. The Vcore is 1.375, Vdimm 2.8. in both cases. I’m sure there is more to go, but this was just to show that the Prescott can be tamed when you rethink what you are doing and try some new things.

Steven4563
02-23-04, 03:23 PM
congrats on the nice rigs it was a nice read :)

thecondor
02-23-04, 04:14 PM
Thanks for the comments. One other thing I'm going to try is a duct similar to what voodoomelon has suggested on the "cooling" thread.
Will take a few days to make, but would like to try one with the 92mm fan.

sir_LOIN
02-23-04, 04:29 PM
From what I've been reading, it's not just the cpu that seems to heat up like crazy, but the motherboard too. How are your mobo temps? Check this out about the msi boards http://www.hardocp.com/article.html?art=NTg5

ozzlo
02-23-04, 05:17 PM
it sucks I had a coice between the prescott 2.8 and the p4 2.8 and I chose the p4 because of the whole cycle degredation and the high temps but the prescotts seem to be doing 8/day more than the p4's at the same speed which is totally amazing.

I had a choice and I went with the reliable stuff:(

of course once i get dual channel my setup might be a little faster but It's definatelly not going to do an extera 8/day:o

*edit*
oh my bad that's for a 3500 prescott:D... ok ok 6 a day sounds a little more reasonable now but still impressive
*edit*

thecondor
02-23-04, 05:49 PM
Well, the sensor labeled "sys temp" in MSI's Core Center reads 32deg C. I haven't had any funny smells or any weird stability problems or hang ups. I think the 120mm fan blowing on the MB helps a lot. The MOSFET heatsinks are slightly warm to the touch. The Northbridge came with a fan and heatsink. I can only say, so far so good!

Edit. The article at HardOCP seems to address boards where the Vcore
is bumped up pretty high, like 1.7 volts. I agree this would be suicide.
My goal was to first, get 24 wu a day. Then find the parameters that
would give the lowest manageable temperature. I'm only at 1.375 V set in the BIOS. I will also agree that when I'm monitoring Core Center, the Vcore does fluctuate more than I would expect. I see from 1.38 to 1.44 V.

Agent_Mull
02-23-04, 07:09 PM
You lapped the core?

thecondor
02-23-04, 08:16 PM
No. I just lapped the heat spreader on the cpu and the contact surface on the heat sink. I lapped the cpu heat spreader down to all copper then mirror finished it with crocus cloth.
MSI's MB monitoring program is called CoreCenter, similar to AsusProbe. Hope that wasn't confusing.

Agent_Mull
02-23-04, 09:21 PM
Oh ya, forgot intels have heat spreaders. Im an AMD guy as you can see by my sig.

TC
02-23-04, 10:14 PM
The prescotts really aren't that hard to cool, in fact I'd worry more about the mobo from what I've seen. Looks to me like none of the current mobo's are truly designed for the prescott from the ground up. I bet prescotts will start looking much better come late spring or early summer. By that time we should see a new stepping which should address the heat and speed concerns, and the first mobo's with solid prescott support should be showing up.

thecondor
02-24-04, 02:33 PM
Completely agree TC. Even though my board is running good and is so far stable, I see more fluctuation in the Voltages than I saw with the 2.6c. My 12V has even dipped to 11.2V on occasion. I think this is due to the voltage regulation on the board rather than the power supply.

Stratcat
02-24-04, 08:29 PM
Well done condor! :clap:

FWIW: I liked the case in my sig so much, I bought 2 of em so far, and will be purchasing another for my next build.

I like the big ol' 120mm's on front intake & rear exhaust.

I realize you've now got a 120mm side inlet.

Have you further considered an intake/exhaust flow-thru cooling path?

Happy crunching! :thup:

thecondor
02-25-04, 07:59 AM
Haven't really considered that yet. My Enermax has a 92mm and and 80mm so it's kinda flow thru. Temps today are 38/54 idle/load. AS5 must be doing it's thing. Pic may be attached. You can see the YS-Tech in the case and the PS fan just above. Everything is positioned pretty well to get the heat out.