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Megahalems not quite holding up to the hype?

faxon

Platinum Member
So, i have an unlapped Q9650 doing 4ghz @ 1.296v as measured from CPUz, but temps under OCCT top out at 68c 65c 63c 63c respectively, and under linpack they go even higher. i remounted my cooler with AS5 from the tuniq TX2 i was using before and my temps went up 2-3c across all cores (to what they are listed as here). given, the IHS of my Q9650 isnt actually machined right. around all 4 edges there is what i can only describe as a ramp leading up onto the IHS that goes about 2mm in at the center, and it goes away a few mm from the corners. so is my Q9650 just running hot, or is my buddies lapped TRUE on his i7 really that much better, with his cpu doing like 56c under linX @ 3.8ghz with more voltage.

specs:
Megahalems + 2 Low Speed yate loons.
Q9650 @ 4GHz 1.296vcore via CPUz (1.325 bios)
GA-EP45-UD3P
4x2GB DDR2-1066 G.Skill (that blue kit that everyone on newegg loves)
EVGA Vanilla 9800GTX 512


i do have a higher CFM fan lying around that i can try using as the push fan, but its to loud for my taste even at the lowest speed i can set it to on my fan controller. if it makes a significant difference i may need to look into ordering some high speed yates instead of the low speed ones im using now, since they seem to do better on acoustics when dialed down via a fan controller (buddy has one)
 
so, after doing some looking around, it looks like yea i was right in my conclusion that my temps are higher than they should be with this cooler on avg, but that lapping it DOES make a difference just like with the TRUE. I checked the surface, and it definitely isnt smooth, and due to the shape of my chips IHS, having a cooler that is convex sure doesnt help much with over all contact area when your CPU is convex as well. im still hesitant to lap the CPU though, since i havent quite figured out a good method to not risk damaging the contact side, and i got frys' extended 3 year warranty on the CPU and mobo, which will be useful since i have never had a mobo last me more than 2 years, and when it goes i could trade both in for whatever is current at the time free of charge. If i do decide to lap the Q9650, any ideas on how to protect the land grid on the back from damage? i figured i would see what types of nonconductive tape i have lying around, since my cpu didnt come with one of those black coverings on it like my e5200 did (came in a plastic clamshell).

would be awesome if i could knock my temps back a ton, since my CPU still has a fair bit of OC headroom on it that it would be nice to take advantage of at some point. im planning a water loop for the end of the summer (once i have money), but any improvement i can get now would be great
 
yea i did some more looking and it seems that folded over, the side of the clamshell that protected that side of the CPU can still be used much like that black plastic cover that they usually use. i dont know why they didnt send my Q9650 with one of the black covers like they used to send, but the box was unopened or tampered with when i got it new. Will post my results for any improvement gained from simply lapping the Megahalems after i do some more looking around to see if i can find any stories which back up prolimatech's warnings of possibly reducing cooler performance by mucking with the base they shipped the cooler with
 
yea i will see about doing that after i get done with class tomorrow. i did some testing tonight but i have to unmount it from my S-1283, remount a dif fan to it if i plan to use it, and then remount it onto my megahalems. then, if that works out, i gotta get a different higher CFM fan, since that fan was just a tester and the motor on it is actually a lot louder than on the medium and high speed yates. i will have to compare a high speed yate vs it at some point, which means going to a friends who has one just to test it out vs my fan, and then ordering one for myself if it indeed makes a difference. from some of the testing i did tonight im not even sure it will make much of a difference. to get much more out of this chip im probably going to need water cooling anyway, since i would have to back off the OC to where i got it to maximum in relation to where my temps are now to set it where i would have my 24/7 stable preference setting (1-200mhz bellow max OC on Core2 based chips). im probably going to remount again anyway with one of the other thermal compounds i have (testing them all) and find which one works the best, and i will do some fan swapping as well then to compare push/pull vs single push and single pull. the megahalems mounting mechanism makes doing testing like this so much easier than with other coolers i have used, either with HDT needing scrubbing between the pipe/mounting gap, or the backplate + spring screws taking forever to get mounted properly. with the megahalems it's just clear the area around the cooler (move the PSU and a fan + bracket), pop the fans off, and unscrew. definitely a tinkerers friend if anything, and it's still standing up well to what im throwing at it regardless of how hot my CPU may be regardless of cooler.


ed: if i cant get any extra cooling performance out of this setup in the range of extra OCing headroom, im going to put my complete water loop plan up for inspection. loop wont be built until i have $800 in the bank though (saving for future projects), cant warrant the loop just yet until i can move some of the other components in this rig around to another one, and i get myself the P-80 armorsuit from lian li i have been drooling over since about february
 
I'm running a q9550@4.25 with TRUE x2 1600 rpm fans, cpu and hsf lapped, getting about 68c-56c avg ~61c in occt. I think lapping your cpu and hsf, and using a good TIM like OCZ Freeze oughtta fix your problems. I'm using 1.392 volts though so I dunno..
 
yea im already using good TIMs. i have a tube of tuniq TX2, some old AS5 which im about to toss since i think its separating and its to thick for my liking, 2 tubes of thermalright chill factor that came with my IFX northbridge/southbridge coolers for another board, and a tube of CF2 that came with a buddies TRUE. I'm still hesitant to lap the CPU since i was kind of expecting it to die before my 3 year frys warranty is up, and if it does i could get a free sandy bridge + X78 mobo or whatever around that time, since they wouldnt have any replacement parts for my system in stock anymore by that time.
 
Originally posted by: faxon
yea im already using good TIMs. i have a tube of tuniq TX2, some old AS5 which im about to toss since i think its separating and its to thick for my liking, 2 tubes of thermalright chill factor that came with my IFX northbridge/southbridge coolers for another board, and a tube of CF2 that came with a buddies TRUE. I'm still hesitant to lap the CPU since i was kind of expecting it to die before my 3 year frys warranty is up, and if it does i could get a free sandy bridge + X78 mobo or whatever around that time, since they wouldnt have any replacement parts for my system in stock anymore by that time.

9650 @ 4ghz I think would last longer than 3 years 24/7... Either way though your call. Might not get much of a temp difference doing it anyhow, and it takes a lot of time and effort to do it right.

Good to see another Browncoat btw.
 
If the IHS is (as you describe) significantly unlevel, only lapping it would correct the problem.

If you choose to ignore the warranty, I can tell you that it shouldn't make any difference for the actual lifespan of the processor.

The IHS and the base of the Megahalem (like the TRUE) are plated with nickel.

Getting both surfaces flat and removing the nickel layer will significantly improve heat transfer. The nickel layer is just as important as the flatness of the two surfaces: it has a much higher thermal resistance (lower thermal conductivity) than copper. Most of the thickness of the IHS is copper, as is the heatsink base once you grind away the nickel.

If you DO lap it, use the black-plastic cap to cover the LGA, or find something that will cover it. Use only a couple drops of water with the sandpaper at any given time; wipe the wet residue off the processor cap regularly, and wash off the sandpaper.

Use 240 or 260-grit wet-or-dri to grind down the nickel plate and get the surfaces flat sooner. By then, the coarse grit will be more like 320. You can finish off with 400 wet-or-dry. It isn't important to get a mirror finish (although some boast and show pictures).

I also recommend diamond thermal paste (like IC Diamond) because it's worth about 2C degrees improvement with a 100W core such as yours. The lapping will get you between 5 and 10C improvement.

Just extrapolating from about three or four benchtest reviews of the Megahalem I've read in the last two weeks -- with the 95W C2Q you're using, I'm guessing that it is worth about 4C in temperature improvement over the TRUE. You DO need to have sufficient airflow, even so. Different people have different tolerance for noise. If it were me, I'd try to thermally control the fan and I'd pick a fan which allows for 1,800 to 2,300 in its mid-rpm range. But that' just me . . . .
 
yea i have grits from 120 to 1500 in my lapping kit right now. i remounted my cooler again last night with the TX2 and noticed that when i remounted it with AS5, the cooler was mounting slightly tilted, putting pressure more to one side of the processor and lifting it off the other, so i bottomed the bolts out and got my temps down to just about 70c under OCCT linpack. As for the info about the metals, i knew all that already, im just trying to find a way to get as much out of this setup as possible before i go to water cooling. and yes, im familiar with the whole boasting a pretty finish process. you must not remember this thread from a few weeks ago hehe: http://forums.anandtech.com/me...=y&keyword1=TRUE+vs+V8
 
Originally posted by: faxon
yea i have grits from 120 to 1500 in my lapping kit right now. i remounted my cooler again last night with the TX2 and noticed that when i remounted it with AS5, the cooler was mounting slightly tilted, putting pressure more to one side of the processor and lifting it off the other, so i bottomed the bolts out and got my temps down to just about 70c under OCCT linpack. As for the info about the metals, i knew all that already, im just trying to find a way to get as much out of this setup as possible before i go to water cooling. and yes, im familiar with the whole boasting a pretty finish process. you must not remember this thread from a few weeks ago hehe: http://forums.anandtech.com/me...=y&keyword1=TRUE+vs+V8

Yeah! Now I remember!
 
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