Legit Reviews

OK, I've got a couple questions concerning heatsink prep that I think I know the answers to but I'm still going to ask just to be certain.
I have a Big Typhoon VX on a AMD 5200+ but these Q&As should apply to all HSF & CPUs.

OK when I first got the system, I just slapped some AS5 on there and set it up cause at the time, I didn't have time to overclock but now I have a little more free time and I know I need to level the contact surfaces for better heat transfer.

• First, how should I go about getting the HSF off? It's 'stuck' on pretty good, can I just wiggle it off or should I try prying?
  In the ASUS Z71 Thermal Pad Removal To Reduce Temperatures topic,

  Apoptosis wrote:To remove the HSF simply un-screw the 4 philips head screws and gently lift off the heat sink. A very small amount of force might be required.

  Next, how high of grit should I go to flatten the surface and what about polishing compounds? I have up to 2000 grit, does 2500 really make much difference?
  In Dry Ice Cooling... Topic,

  Apoptosis wrote:Look at the surface that is going on the CPU...
  
  
  
  Time to take some 600 grit to 2000 grit sandpaper and do some wet sanding on this sucker....
  
  
  
  oh yes a mirror finish on the cap bottom and 600 grit on the tube just to give it some bling before it gets wrapped up.

  So 2000 grit looks like a good target.
  
  Should I give the processor a few laps as well or will this possibly kill the CPU? Also, how should I secure the processor for sanding without bending the pins?
  In the about lapping my P4 2.6C cpu topic,

  Apoptosis wrote:As far as lapping and holding the actual processor... I use an old socket that I have laying around. That way I don't damage the pins.

  • Anyone know any other good solutions? (for those of us that don't have extra sockets)
    Ok, looked on wikipedia, Polystyrene (basically styrofoam) has a electric conductance of 10^-16 S which translates to a resistance of 10,000,000 gigaohms/m. I'd est. the distance between CPU pins at 1mm so using polystyrene to hold the CPU will mean the resistance between pins is about 10,000 gigaohms. I'd say it appears pretty safe to use polystyrene to hold you chip while sanding. I'll try and find a more reliable source for the electric conductance though.
  Finally, how much AS5 is to much and how do I know if I have enough?
  In the How much AS5 is enough? topic,

  kenc51 wrote:put about as much as an uncooked grain of rice on it.
  
  You can try spread it out or just leave it, the pressure from the heatsick and the heat will make it spead out over the cpu naturally.

Ok, so I did some research and found some answers to the questions. I'll try to make it a little more definitive and as also comments/suggestions are very welcome.
Maybe a Sticky? (please )

I was wondering the same....I got a VX myself and I think the bottom of it is pretty badly machined, I wanted to know how to sand it evenly/what grit to use.

Sorry, whats the styrofoam for?

For a step by step search for "Lapping Guide" on google.

Dan

To hold your CPU while lapping the top...I actually just did this to both CPU and HSF and got a 5-6C drop. Worked like a charm.

I alwaya lap any heatsink I get. No sense on installing it since I will lap it anyhow.

Gamble wrote:I was wondering the same....I got a VX myself and I think the bottom of it is pretty badly machined, I wanted to know how to sand it evenly/what grit to use.

I use a peice of think glass and depending on how ravaged the base is, you would use different grits.

Yeah, my Typhoon was pretty bad too, I had to start with 400grit sandpaper to level it. Also, my CPU (started with 800) was slightly concave but relatively flat. Mirror finish on both now. Be aware that if you lap your CPU, it voids your warranty (in other words, don't do it until you sure that you have a good CPU).