VRAM heatsinks & good double stick thermal tape?

[EliteRetard]

Do you know of a good brand that will cool well and actually stay stuck without being permanent? I heard it said several times that VRAM doesn't get hot and doesn't need cooling...FLAT OUT LIE. Stock speeds this stuff is getting blisteringly hot (I know, I touched one). This system has the MOBO laying flat with the GPU sticking up out of it with VRAM on both sides. If the heatsinks fall off they will land on the MOBO and probably damage or short something out.

So what do you guys use?

 

[Cerb]

Do you know of a good brand that will cool well and actually stay stuck without being permanent? I heard it said several times that VRAM doesn't get hot and doesn't need cooling...FLAT OUT LIE.

It doesn't need need cooling on the back side. Most of the heat is going into the PCB. The RAM doesn't use much power, but can get hot (and normally, that's fine). Not that added cooling from the other side of the package will hurt, but it's not doing a ton of good.

"Blistering hot," could be as low as 140F.

There aren't non-permanent adhesive pads, however, unless you could needing to scrub with solvents later on, "not permanent."

So what do you guys use?

A few mm of air. It's all I have room for, anyway.

 

[Face2Face]

I've used this 3M tape. Works well on memory heatsinks.

http://www.frozencpu.com/products/1...onductive_Adhesive_Transfer_Tape_-_2_x_2.html

I've never used this exact heatsink, but they look fine.

http://www.frozencpu.com/products/2...15mm_-_Black_Anodized_Aluminum_-_10_Pack.html

 

[Cerb]

I've used the 8810 variant of that tape, and it's pretty good. After settling in, though, it comes off easy, with some wiggling, but does not come off clean.

 

[EliteRetard]

Comes off easy sounds good, but doesn't come off clean and needs scrubbing...what are we talking about here? Like an hour of careful scouring or a few minutes with a tissue and some IPA?

I wondered what the differences were between the variants, and found this PDF:
http://www.adafruit.com/datasheets/3m8810.PDF

The obvious difference is the thickness, but there's a bunch of other data there too, like thermal impedance...I'm guessing lower is better? It looks like thicker is stronger, but heat weakens them? I noticed they suggested 50PSI to mount two hard surfaces, that seems like a lot...any idea what that would be practically and if that would harm the VRAM/PCB?

Thanks for the input.

 

[EliteRetard]

*snip*

"Blistering hot," could be as low as 140F.

*snip*.

I felt like clarifying this.

I'm quite heat resistant and can handle a cast iron pan after frying stuff. I wash my hands in 130F water. So if I say blisteringly hot and it's enough to sear my flesh in a second it's pretty friggen hot. Unfortunately I don't have a means to measure the actual temperature, but I don't doubt its 90c/200F+.

I did a quick search and found others had done some measuring though:

They got temps upwards of 80c on the VRAM in open testbed. I have an ITX case with low airflow, its toastier for sure. Any bit of heatsink that can catch a whiff of air should help. Even if it's only 5c cooler I'll take it.

 

[Cerb]

The obvious difference is the thickness, but there's a bunch of other data there too, like thermal impedance...I'm guessing lower is better? It looks like thicker is stronger, but heat weakens them? I noticed they suggested 50PSI to mount two hard surfaces, that seems like a lot...any idea what that would be practically and if that would harm the VRAM/PCB?

Thicker is lower performance, but more fragile (easier to tear, when you meant to stop cutting, harder to apply evenly, etc.), and only the thinnest comes on a roll, IIRC . The stuff is strong enough to replace epoxy, so can be used in equipment that has to survive abusive testing, like drop tests, vibration tests, high-G impact tests, etc.. I don't think you have to worry that much.

 

[EliteRetard]

So the thicker stuff is "worse" all around (weaker and hotter)?

Epoxy is what I don't want, that's permanent.

Trying to decide if I should try the 8810 or 8815, still wondering how hard it is to remove/clean this stuff.