You have happened to come across one of my 4 favorite topics in which to rant.
You got me in a good mood, so here goes.
There are 3 ways to transfer heat.
Conduction. - A solid object absorbing the head from another solid object (This is the best way to transfer heat)
Convection - Vapor or a liquid carries away the heat. (Second to Conduction, )
Radiation - The heat radiates across a void. (for example the Sun, or Toaster coils) The least efficient way to transfer heat
Radiation is so bad, it is almost like insulation. When it comes to conduction, copper is one of the best.
Copper's ability to transfer heat is about 400W/mK, while Aluminum is only about 200W/mk
Thermal Pastes or Thermal pads can be in the range of 5 to 9W/mK
As you can see, Thermal pastes, and Thermal Pads don't do any where near as good as direct Metal to Metal contact.
However, the slow transfer of heat through TIM, or Pads is still far better than an insulating void that traps heat.
Application of Heatsinks to Chips is almost a lost art. People underestimate the amount of effort that should go into the application of said items. A jewelers precision is required.
The aim is metal to metal contact. Period. You get that and you win. Big time.
But it is Not as easy as it looks. People get two shiny pieces of metal and lie one on top of the other and say, oh that's good contact. How often they are fooled. You're telling me that you could pull a piece of paper out between Heatsink and the chip? That tells me you have a deadly, heat trapping void!
Internet users and even Manufacturers (who supply pre-applied paste) take the lazy way out. Manufacturers, when they sell you a heat sink, they supply Way too much Paste on it. Why? Because for them it is better to ensure that SOME contact is made rather than the best contact. Manufacturers can not take the chance that no contact is made.
The more paste that is applied, the greater the distance heat has to trudge thorough that 5W/mK paste. There is a YouTube video where this guy Linus has his two friends Steve and Jay try to find build errors in Like constructed PC's. Paste was missing in both PC's. Steve found the error and applied gobs of it. Jay didn't notice, and his build was completely void of paste. Jay though had better temps in the end than Steve. I laugh at this because Steve made a separate video on his channel, concluding that the application of paste barely matters. However on that video, when he used a "light application of paste", it was still way too much.
So: Here is what you need to do:
You must determine where contact is being made. Clean both surfaces. Then apply the smallest amount of paste to one. You don't want to layer it. It should have almost NO thickness. Think of a teenage girl, how much would she put on a pimple. She would not leave a layer of this. Now Apply (screw it down) the Heatsink to the chip(or board). Then remove it. You should see exactly where contact is made. This is where you have to sand (either 400 or 800 grit). Keep doing this until you get contact in the center. I rather sand the heat sink, it is cheaper. However, your results will indicate what you have to do. Do not worry that the surface is getting scratchy. A scratched surface with a minor amount of Tim, does so much better than a warped one with gobs of Tim between.
My dentist, when he worked on my teeth use to use carbon paper to test the contact between upper and lowers.
You have to test the contact. It's work, but experience has shown me that one can't trust one's eyes when it comes to such things. The results will amaze you. Like I said, it's a lost art.
I've enclosed some pictures from years ago, highlighting this topic.
If you do this right, you get a cooler system. You get a quieter system, and you get a faster system.
Good Luck.
You have happened to come across one of my 4 favorite topics in which to rant.
You got me in a good mood, so here goes.
There are 3 ways to transfer heat.
Conduction. - A solid object absorbing the head from another solid object (This is the best way to transfer heat)
Convection - Vapor or a liquid carries away the heat. (Second to Conduction, )
Radiation - The heat radiates across a void. (for example the Sun, or Toaster coils) The least efficient way to transfer heat
Radiation is so bad, it is almost like insulation. When it comes to conduction, copper is one of the best.
Copper's ability to transfer heat is about 400W/mK, while Aluminum is only about 200W/mk
Thermal Pastes or Thermal pads can be in the range of 5 to 9W/mK
As you can see, Thermal pastes, and Thermal Pads don't do any where near as good as direct Metal to Metal contact.
However, the slow transfer of heat through TIM, or Pads is still far better than an insulating void that traps heat.
Application of Heatsinks to Chips is almost a lost art. People underestimate the amount of effort that should go into the application of said items. A jewelers precision is required.
The aim is metal to metal contact. And use as little paste as possible. Period. You get that and you win. Big time.
But it is Not as easy as it looks. People get two shiny pieces of metal and lie one on top of the other and say, oh that's good contact. How often they are fooled. Your telling me that you could pull a piece of paper out between Heatsink and chip tells me you have a deadly void!
Internet users and even Manufacturers (who supply pre-applied paste) take the lazy way out. Manufacturers, when they sell you a heat sink, they supply Way too much Paste on it. Why? Because for them it is better to ensure that SOME contact is made rather than the best contact. Manufacturers can not take the chance that no contact is made.
The more paste that is applied, the greater the distance heat has to trudge thorough that 5W/mK paste.
So: Here is what you need to do:
You must determine where contact is being made. Clean both surfaces. Then apply the smallest amount of paste to one. You don't want to layer it. It should have almost NO thickness. Think of a teenage girl, how much would she put on a pimple. She would not leave a layer of this. Now Apply (screw it down) the Heatsink to the chip(or board). Then remove it. You should see exactly where contact is made. This is where you have to sand (either 400 or 800 grit). Keep doing this until you get contact in the center. I rather sand the heat sink, it is cheaper. However, your results will indicate what you have to do. Do not worry that the surface is getting scratchy. A scratched surface with a minor amount of Tim, does so much better than a warped one with gobs of Tim between.
My dentist, when he worked on my teeth use to use carbon paper to test the contact between upper and lowers.
You have to test the contact. It's work, but experience has shown me that one can't trust one's eyes when it comes to such things. The results will amaze you. Like I said, its a lost art.
I've enclosed some pictures from years ago, highlighting this topic.
If you do this correctly, you will have a quieter PC. You will have a cooler PC, and you will have a faster PC
Good Luck.
Hey, thanks for your reply.
The thing is that there does appear to be good contact, but it doesn't behave that way while running. I'm just posting this because I am somewhat reluctant to take sandpaper to my 900 dollar graphics card so I wanted to check with you first.
I opened it up after a couple of days after giving up and there seems to be decent contact all over, but I could be wrong. This is with the washer mod:
There you go. Did three tests with differing amounts of paste.
Also, I was not able to remove the paper when using the washer mod, which I also did here.
Thanks
Edit: Sorry bout the formatting, not sure what to do about that.
A washer mod is just placing nylon washers on the spring loaded screws so they create more tension and pressure on the die.
Here you are. I tried to spread it as thin as I could with an old card.
Could have been a little less... but now we are getting somewhere..
You can see by the Blue circles where the ridge is making contact first. These Blue area stop any red areas from getting contact..
There is a void in the red areas, and they can only rid themselves of the heat, by having it to transfer to another part of the heatsink.
Now let me say first, that this might not be the worst contact I've seen. I don't think it should have made the thermals as bad as they are, but they did contribute to them.
Before sanding the heatsink in the area of the blue (with 800 grit or finer). I'd clean the heatsink once again. Take another impression, and verify that your contact pattern is somewhat consistent. (That is, that it is not because of screws tightening.)
If you get a consistent pattern, I would sand down the area of high contact (The blue parts). I personally don't worry that the heatsink gets scratched. You would be looking for a more overall contact pattern for your final result.
But what you do is up to you.
