Direct-Contact Cooling solutions.

[Majestic]

Who or what actually drove the market towards these types of contact surfaces? They usually have a very coarse finish and rarely give all heatpipes proper contact to GPU's/CPU's. 

When I still had my 670, which was the ASUS DirectCU II model, you could clearly see it made poor contact with the block. If you put heavy load on the GPU (TIM was Liquid Ultra) it spiked 20/30deg in an instant. Much like my 4670K's behaviour before delidding, illustrating where the problem lies.

 

If you look at companies like Be Quiet and Noctua, one of the leading companies in terms of premium coolers, still using baseplates... it makes you wonder. Were they just another budget cut cloaked in marketing-BS to sell it to us? Because it seems to me they're not really any better than proper polished/finished baseplates. They're actually worse.

 

Especially in light of EVGA's ACX 2.0, the problem really surfaces...

 

http://www.bit-tech.net/hardware/graphics/2014/09/19/nvidia-geforce-gtx-970-review/3

[LukaP]

well, if we look at thermodynamics, there is less heat resistance between the heatpipe and the chip this way, but yes, sometimes not all heatpipes make contact like this. but in the case of ACX, it doesnt matter, since the card runs cool on those 2 alone

[Zeke]

Yeah, the chip doesn't touch the third heatpipe directly, but those are embedded into a single piece of aluminum (or whatever that is) so the third one also has some work to do.

[Guest Kloaked]

Was a new thread really needed for this?

[Majestic]

well, if we look at thermodynamics, there is less heat resistance between the heatpipe and the chip this way

 

But with that, you're implying the resistance is less on direct-contact and the solder used between the baseplate and the heatpipes being less than copper's w/mk. Which may not be the case, given their usual unpolished surface.

 

@Kloaked , well with more companies going towards this technique, asking the question is maybe useful..

[LukaP]

But with that, you're implying the resistance is less on direct-contact and the solder used between the baseplate and the heatpipes being less than copper's w/mk. Which may not be the case, given their usual unpolished surface. If you use

im not implying. it is. the gain of resistance you get from the rather bumpy plate is waay less than what you lose by getting rid of those 3-4mm of alu between them and the core

[Guest Kloaked]

But with that, you're implying the resistance is less on direct-contact and the solder used between the baseplate and the heatpipes being less than copper's w/mk. Which may not be the case, given their usual unpolished surface.

 

@Kloaked , well with more companies going towards this technique, asking the question is maybe useful..

 

Well everyone's basically discussing that on the news thread.

[Majestic]

im not implying. it is. the gain of resistance you get from the rather bumpy plate is waay less than what you lose by getting rid of those 3-4mm of alu between them and the core

 

Yeah, offcourse you use a copper baseplate. Like those old zalman units used to have.

http://www.frostytech.com/articleimages/200607/zalmanVF900Cu_clip2.jpg

[LukaP]

Yeah, offcourse you use a copper baseplate. Like those old zalman units used to have.

http://www.frostytech.com/articleimages/200607/zalmanVF900Cu_clip2.jpg

thats expensive you know...

[Majestic]

thats expensive you know...

 

Yeah I know, so it's a budget thing apparently? They used to sell it as an improvement over baseplates. Which is just wrong.

[Syntaxvgm]

I would actually think that there is, in some cases, benefit to base plates. The gaps caused by the roundness of the heat pipes are better compensated for if the base plate is made right. Basically more contact on the chip, and hopefully better transfer to the heat pipes give the base plate makes full contact with the heat pipes, and not just flat. 

However, I would argue on GPUs, where vertical space is a premium, there is benefit to not using base plates and trading that off for more heatsink surface area

Of course I'm just spewing bullshit, it's all opinion, I've never actually seen a test of any kind for this. 

[Briggsy]

Direct contact makes sense to me if the gpu/cpu has its own heat spreader. However, heatpipes touching the die itself has always given me the heebie-jeebies. I'm not sure whether its because of the slight exanding/contracting of the pipes potentially scraping the silicon, or its just the often rough surface of the pipes. I'm pretty sure companies that use direct contact heat pipes on the naked gpu surface know better than me, So I'm probably over-thinking it.

[Wauthar]

Isn't this also the issue with the Asus 290 DCU2 card? People were complaining that the cooler was inefficient.

(note that I have one of those...)