Cooling Not enough thermalpaste

Hey guys

Okay in most cases too little is better than too much right? Does this go for thermal grease also? How would a really good heat sink perform with not enough thermal grease?

 

well you only really need a pea sized amount on the CPU for it to be best effective
what do you mean by "not enough"? like none?

 

Even less than a pea's worth tbh Dave - a grain of rice for heatspreadered chips is about right.

 

Well I use this Zalman thermal compound and it has a brush like the nail polish women use, I just painted the whole area of the processor.

 

If you followed the instructions provided, then that'll be fine.

One funny I did spot in the specs... Why the hell do we need to know the Specific Gravity of a thermal compound?

 

HAAH! Thats so true I didnt even notice that, I guess they wanted to add as much info as they could?

 

depends how big your peas are ...

 

If you put too much on the heatsink will usually squeeze out some, just check the temps under load, if they look fine I would not worry.

 

the thing is when I'm running intelburntest my CPU would reach mid 80's, and I cannot lower my CPU voltages, CPU PLL voltages, FSB voltages...etc or my comput would get the blue screen. SO I'm guessing I put to much paste or I did something wrong. I have a Thermalright True 120 + Antec 900, Q6600 overclocked to 3.4GHz, Multiplier: 8.0 x FSB: 425.

 

I found the bottom of my TRUE wasn't flat, resulting in high temps. See this thread: http://forums.bit-tech.net/showthread.php?t=150005

Basically I lapped it and re-applied more thermal paste to make sure I filled the gap.

I was struggling with temps at 3Ghz though, you're at 3.4. Do you know what your ambient temps are, roughly?

 

IBT is the most demanding CPU test there is, you are likely to see temps that high or higher.

 

The temp in my house is probably 20*C (Wild guess). The bottom of my True was really flat all my temps are all or par with each other. My Idle temps are 38-36-35-35 the thing that worries me is my full-load temps, they reach 85-85-85-85!

 

I noticed, Prime95 maxes my temps to 75*C but IBT is just mean.

 

The IHS on my Q6600 was concave so i went one step better and lapped it all the way down to 1.5 micron (yes i have the technology! ahahahaha!)

But i dont know what my new temps are just yet as i am waiting on my new board to arrive.

 

Well if you can't lower voltages, and you probably have the best air-cooled solution available, I'd say the only option left available to you (to drop temps) is to simply lower the clock speed.

Alternatively, though it won't make much difference, add a second fan to the TRUE (in push/pull) so it draws more air through, and also get more case airflow (may require a new case).

But other than that, if you can't lower voltages just lower the clock speed, as it's a pretty huge overclock.

 

Your only suppose to haze the mating surfaces(cpu and heatsink).

Metal to metal is best. Metal to thermal compound is better. Metal to air is worst.

The paste is only meant to fill in all of the surface imperfections that the human eye cant even see. You want as much metal touching as possible. Thats the whole idea. You dont want the heatsink to float on the paste.

 

Lol okay I just opened up my case and ripped everything out got down to the CPU and cleaned the old thermal paste and added more, what I did was painted thermal paste on the CPU and on the bottom of the TRUE Black 120. To my suprise it dropped my Temp almost 10*C.

Now my goal is to look into lapping the CPU and the heat sink, I understand that I need sand paper? Is there a specific type I need to get?

 

there are alot of guides out there about lapping heatsinks, the same process can be used for your CPU.

Lapping a CPU is a little more difficult because the IHS is nickel plated copper and removing the plated surface takes so effort.

200, 400, 600, 800, 1000, 1500, 2000, 2500 grit papers are what are needed for a normal lapping and will provide a mirror finish in the end if done right.

I kicked the standard up as i have some special papers, well more of a cloth rated from 2500, 6000, 8000, 12000. I'll get some pics up tomorrow maybe.

 

Getting a flat base really only requires up to 800, anything past is just bling and doesn't increase performance.

 

I could only find up to 600 grit, seems to have worked fine, the thermal paste fills in the rest.

B+Q (big hardware store) only did up to 600, but automotive shops will often have finer grits if you struggle to find them elsewhere.

Some online computer hardware shops sell lapping kits. They include a sheet of glass to rub against so you can know you're getting a level base. I just used a spare bit of perspex.