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Stumped, high temps after lapping / Megashadow..

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February 19, 2010 2:23:02 AM

Ok, I've just about had it and not sure what else I can do to lower my temps. After lapping both my heatsink and cpu, I've gained minimal decrease in temps, perhaps 1-2 celcius at most. I have the Megashadow in a Sniper case with high airflow and I'm stilll getting horrible temps.

I've seen other heatsinks with MUCH better results and I'm not sure if it's the cooling problem anymore. What else can be the cause of these high temps? A bad cpu? A bad motherboard?

i7 920 @ 4ghz, 1.35 Vcore (only way to get stable)

prime95 for 10 hours = 82 82 76 76 max

I'm using Arctic Silver 5 and I've spent almost a whole tube applying and reapplying incase I've messed up it's application. I did the dot method, line method, spread method and none of them showed a significant decrease (spread being the worst one).

I know I can just lower my clock and leave it at that but I got into this hobby of overclocking and after spending money on sand paper, a glass sheet, high CFM fans and etc.. I want to be able to achieve what most people are getting.

Again, would having bad pins on the motherboard or a defective cpu be the culprit of high temps? While I was lapping my Cpu, I noticed a slight discoloration on the bottom. Part of it was slightly darker yellow/brown.
February 19, 2010 3:04:32 AM

What are you using for reading temps? Whats the orientations of the CPU in terms of airflow? Was there a thin layer of thermal paste (too much is bad, too little is bad)? Whats ur idle temps like? Whats ur motherboard for comparision?

There shouldnt be a whole lot of thermal paste applied if u lapped both parts.
a b K Overclocking
February 19, 2010 4:50:46 AM

A temperature decrease of about 2 degrees celsius is normal. That's what others are usually reporting. When I lapped a cpu and heatsink my temps dropped just a litlle bit less than 2C. It's normal

You mentioned using Artic Silver 5. I hope you realise that is an older thermal compound that requires 200 hours of operation and a lot of powering on and off in order for the compound to cure and and stabilize. it does not sound as if you have allowed the compound to cure.

Last time I checked there were over 80 thermal compounds available in a variety of categories. Everyone has their favorite. I used IC 7 Carat Diamond for the past two years. It works for me. No curing required. Just apply and run prime 95 at 100% load for an hour.

You also mentioned that you overclocked. Overclocking will raise temperatures. 4Ghz is pretty good considering the sweet spot is down around 3.6Ghz.



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February 19, 2010 9:43:09 AM

Thanks for the replies.

My motherboard is an ASUS P6T, I have a thin layer of TIM applied since I've done it several times now using different methods. I'm in Japan and it's winter here so with my heater turned on my ambient is around 20 - 25 celcius after a few hours of letting my room warm up. My heating unit is set on 25 celcius so it shouldn't get any warmer than that.

My idle temps after running prime95 (warmed up the cpu) is around 38-40 celcius. On load it goes all the way up to 82 max after 10 hours of prime.

I'm aware that using AS5 needs a lot of curing time but even then, the temperature shouldn't go above 80 celcius as I've been comparing to other people who also use AS5 w/ the Megashadow. I'm also aware that overclocking to 4ghz raises my temperature but that's the point of me doing all this extra work.

I'm just wondering if there are other defects that may cause the CPU to be run hotter than they should, whether it be a bad seal (the black rubber thing around the CPU IHS) or a bent/damaged pin on the motherboard. I also noticed that on my motherboard's socket, all the pins are straight except 2. They are somewhat in a slant and I'm not whether that's intentional or should all the pins be aligned the same way. Wish I could find a pic of what a regular ASUSP6T motherboard socket should look like for comparison. The manual doesn't show it.
a c 131 K Overclocking
February 19, 2010 10:46:57 AM

Oatmealz said:
Ok, I've just about had it and not sure what else I can do to lower my temps. After lapping both my heatsink and cpu, I've gained minimal decrease in temps, perhaps 1-2 celcius at most. I have the Megashadow in a Sniper case with high airflow and I'm stilll getting horrible temps.


While lapping might help a poorly machines product, a well engineered and finished product is damaged by lapping.

From the Prolimatech Home Page:

http://www.prolimatech.com/

Lapping Warning!
Prolimatech does not condone any type of lapping done to the CPU or to heatsink base. Every Prolimatech's heatsink base is designed on a pin-point scale of how the base is to be flat and/or curved where it's needed to be. We have programed our machines to machine the surface in a very calculated way. Any after-manufacture lapping or modding done to the base will alter the design, hence negating its performance factor as well as its warranty.

Your other problem is Artic Silver.

http://www.arcticsilver.com/as5.htm

Due to the unique shape and sizes of the particles in Arctic Silver 5's conductive matrix, it will take a up to 200 hours and several thermal cycles to achieve maximum particle to particle thermal conduction and for the heatsink to CPU interface to reach maximum conductivity. (This period will be longer in a system without a fan on the heatsink or with a low speed fan on the heatsink.) On systems measuring actual internal core temperatures via the CPU's internal diode, the measured temperature will often drop 2C to 5C over this "break-in" period. This break-in will occur during the normal use of the computer as long as the computer is turned off from time to time and the interface is allowed to cool to room temperature. Once the break-in is complete, the computer can be left on if desired.

http://benchmarkreviews.com/index.php?option=com_conten...

So by my estimation of this statement it would take almost a year of normal use to properly cure the AC5 compound, or almost nine days of continuous power cycles to meet their recommendation. Benchmark Reviews feels that this is a characteristically unreasonable requirement for any TIM product, and we do not support it. We want products that perform without the burden of sacrifice on our time, especially with some many competing products offering performance without this extra requirement.

I'm typing from a box w/ the Mega on a 920 w/ IC Diamond 7 Karat TIM. Temps under the various saved OC profiles are:

365/24 Profile: 58 54 55 54 @ 3.7 Ghz and CPU Voltage @ 1.125 volts all other BIOS settings default.
Gaming Profile Profile: 74 71 70 70 @ 4.2 Ghz and CPU Voltage @ 1.300 volts, HT Off, all other BIOS settings default.
Experimental Profile: 72 68 67 66, @ 4.4 Ghz and CPU Voltage @ 1.240 volts, HT On, many BIOS settings changed.

February 19, 2010 11:47:39 AM

Ok either my temp sensors are fubared or .. I dunno please shed some light. I left my computer on for about another 10 hours so that's about 20 hours total since the last time I've reapplied the thermal paste AGAIN. I went out to grab some dinner and saw that my temps went all the way down to 65 65 59 59!!

I didn't make any modifications since last night where it was at 82 82 75 75. It was low for about 5 minutes then it went back up as I'm typing this to 75 75 70 70. All this is with Prime95. On my AsusProbeII, the Cpu core itself is only 66 celcius.

Seriously, this has been a weird ordeal. Would this have to do with the way the thermal paste is expanding under the heatsink?
a c 86 K Overclocking
February 19, 2010 1:23:49 PM

Your using the MObo temps software? Aha! They are pretty much panned as crap. Most of us use HW Monitor, or Realtemp instead.

You also haven't mentioned what fans your using on the HS.

February 19, 2010 1:27:20 PM

Nah I'm using ASUSProbe to check the CPU temp and using Real temp to check the individual core temps. My TJMax is set at 100 for Real temp. As for the fans on the HS, I'm using 2 Ultra Kaze 2000s in push pull.

As I understand the Core temps are about ~5 celcius from the CPU Temp...
a c 86 K Overclocking
February 19, 2010 1:39:08 PM

Yep, about right. I can't see anything odd about your system. Won't be your mobo, thats for sure. You got the backplate on properly?

I use the bigger than a grain of rice, smaller than a small pea of paste and let the screws squish the paste. I use MX-2 paste, but don't think thats your problem.

You could have a sucky chip, thats all. I'd keep it under normal usage about 70C, max is 73C or so.

If you don't need HT on, turn it off, that helps a lot.

Maybe this will help?
http://www.overclockers.com/megashadow-lapped/
a b K Overclocking
February 19, 2010 2:21:00 PM

Conumdrum - I followed the link and read the article. It doesn't look like icebob lapped the cpu to match the lapped heatsink. Would not have made much of a difference anyway.
a c 86 K Overclocking
February 19, 2010 3:02:03 PM

Agreed. His temps before and after wasn't much diff. but they were lower. The ops setup looks fine, dunno why it's that much hotter.
February 19, 2010 3:08:32 PM

Ok, I'm gonna assume my CPU is a piece of crap and it's the worst lol. I'll just keep it as it is and if it breaks on me, it'll give me a reason to go out and buy a new cpu when it comes out =D. Thanks all.
a b K Overclocking
February 19, 2010 3:37:48 PM

Oatmealz - I would suggest simply letting the AS5 cure. Depending on how much you use the pc, it may take a while to run it for 200 hours. It also needs to power on and off too during the curing process.
a c 131 K Overclocking
February 21, 2010 3:27:16 PM

Oatmealz said:
Ok either my temp sensors are fubared or .. I dunno please shed some light. I left my computer on for about another 10 hours so that's about 20 hours total since the last time I've reapplied the thermal paste AGAIN. I went out to grab some dinner and saw that my temps went all the way down to 65 65 59 59!!

I didn't make any modifications since last night where it was at 82 82 75 75. It was low for about 5 minutes then it went back up as I'm typing this to 75 75 70 70. All this is with Prime95. On my AsusProbeII, the Cpu core itself is only 66 celcius.

Seriously, this has been a weird ordeal. Would this have to do with the way the thermal paste is expanding under the heatsink?


More likely has to do with the paste thinning and laying more evenly. Also make sure you don't load two temp monitoring software programs.....this has been known to cause false reporting especially w/ Asus probe.....Asus probe if left on in my box, beeps with 65 volt readings to my NB, SB, CPU and memory.....beeps for 2 seconds and goes away.....no other monitoring software does this so I think Probe is bonky.

I saw a substantial decrease when I drive temps to 78 for about 10 minutes.....when I reset the OC profile to what it was, I picked up a couple of degrees.
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