HD5970 cooling

[cbn]

http://www.anandtech.com/weblog/showpost.aspx?i=657

According to this Blog the right sided VRMs are a bottleneck to Overclocking HD5970.

I am assuming this happens as a result of designing the video card to keep a manageable length.

Could a water block solve this problem? I have seen some advertised blocks claiming the VRMs can be cooled by water (but I know nothing about water cooling)

How about an aftermarket aircooler?

Overall this GPU seems like a much better value than HD5870 (Two full Cypress cores for only 50% more money). Unfortunately I think the cooling solution required to fix the problem may negate some of the price advantage.

 

[CitanUzuki]

thermalright has a solution for the 5870 and 4890. I have one for my 4890 and can tell you they work very, very well. My temps dropped 20 c when compared to stock at full load. this was the first thing i thought of when i read that article, if thermalright releases one that fits the 5970 it might solve the overclocking problem. Just curious though, what about the vrm's in the middle, are those not aversly affecting the overclock?

 

[cbn]

if thermalright releases one that fits the 5970 it might solve the overclocking problem.

Which thermalright sink are you talking about?

http://www.svc.com/fan-4870x2.html

This sink for the 4870x2 I found earlier. It looks like a similar design *might* work for hd5970 provided the cutouts for the VRMs are large enough.

 

[thilanliyan]

I have a Zalman RHS 90 VRM heatsink on my 4870 1GB with the waterblock and they barely break 60C now whereas before they could hit 90C easily.

Here's my mini review of it:
http://forums.anandtech.com/showthread.php?t=310039&highlight=zalman

 

[cbn]

I have a Zalman RHS 90 VRM heatsink on my 4870 1GB with the waterblock and they barely break 60C now whereas before they could hit 90C easily.

Is it possible to get a waterblock that can cool the VRMs also?

 

[thilanliyan]

Is it possible to get a waterblock that can cool the VRMs also?

It is possible to get one that will cool the VRMs but whether they are cooled by actual water channels inside the block is another story. Some blocks do however and you'll have to find which ones are like that.

 

[cbn]

It is possible to get one that will cool the VRMs but whether they are cooled by actual water channels inside the block is another story. Some blocks do however and you'll have to find which ones are like that.

Does internal complexity of the water block greatly factor into manufacturing costs?

The other day I saw a water block listed for hd5970 (that claimed to cool VRMs) but it was $149.

 

[thilanliyan]

Does internal complexity of the water block greatly factor into manufacturing costs?

The other day I saw a water block listed for hd5970 (that claimed to cool VRMs) but it was $149.

I'm not sure how much those kinds of things add to the cost as I've stuck to GPU only blocks since you can reuse them with newer cards (the 4870 is the 3rd card I've used my DD Maze4 acetal block on).

Taking a look at this:
http://www.techpowerup.com/109522/Koolance_Ready_with_Radeon_HD_5970_Water-Block.html
it's still difficult to tell from that pic alone whether there are channels there but in all honesty, it probably wouldn't make much of a difference. I'm sure the need for heat to conduct from where the VRMs are to where a water channel actually is wouldn't degrade performance greatly.

Looking at this:
http://www.ekwaterblocks.com/shop/b...r-blocks/fc-5970-series/ek-fc5970-nickel.html
I think the water actually passes over the VRM area.

 

[Schmide]

Once you remove the heat generated by the chips by the watercooling, the VRMs should be easily cooled by a light fan and a decent heat sink. Considering it's a DC to DC regulation, the efficiency should be near the single digits. 300w peak card, so VRM < 30w.

I'm sure they do a lot better without some 250w of heat passing over them.

 

[thilanliyan]

Once you remove the heat generated by the chips by the watercooling, the VRMs should be easily cooled by a light fan and a decent heat sink. Considering it's a DC to DC regulation, the efficiency should be near the single digits. 300w peak card, so VRM < 30w.

I'm sure they do a lot better without some 250w of heat passing over them.

I can tell you after I put my GPU only block on my 4870, I left the backplate on to test cool the VRMs and RAM and it still got pretty hot (albeit at about 40% fan with a custom shroud) which is sorta why I eventually got the Zalman VRM heatsink.

 

[cbn]

I can tell you after I put my GPU only block on my 4870, I left the backplate on to test cool the VRMs and RAM and it still got pretty hot (albeit at about 40% fan with a custom shroud) which is sorta why I eventually got the Zalman VRM heatsink.

How does the Zalman VRM heatsink do compared to what you had previously?

Are you still using the 40% fan with custom shroud?

 

[Schmide]

WC with a block 4870s here too. I just point an 80mm fan at them. I don't have digital regulators so I can't tell you the temp, but they're cool to touch, a bit warm under load.

 

[scooterlibby]

Wow I can't believe I missed that anand followup. It's weird, though, a lot of the other sites did not have this problem and got excellent overclocks. I think some of them, Tom's for sure, got cherry picked cards. That's kind of a bummer, and something I'll have to keep in mind while considering getting this card.

 

[cbn]

WC with a block 4870s here too. I just point an 80mm fan at them. I don't have digital regulators so I can't tell you the temp, but they're cool to touch, a bit warm under load.

You run two HD4870s in Crossfire?

How do you make enough room in between the cards for the 80mm fan? (I am assuming the fan for the top cards VRMs is sandwitched in between the PCI-E slots)

 

[thilanliyan]

WC with a block 4870s here too. I just point an 80mm fan at them. I don't have digital regulators so I can't tell you the temp, but they're cool to touch, a bit warm under load.

That's probably why...it's the digital ones that get very hot and all the reference cards have them.

 

[cbn]

Wow I can't believe I missed that anand followup. It's weird, though, a lot of the other sites did not have this problem and got excellent overclocks. I think some of them, Tom's for sure, got cherry picked cards. That's kind of a bummer, and something I'll have to keep in mind while considering getting this card.

http://www.guru3d.com/article/overclock-radeon-5970-guide/3

They got 935 Mhz on the core.

But with ASUS Voltage tweak HD5850/70s doing 1035-1050 Mhz I don't see why this card couldn't go higher provided Cooling and PSU were sufficient.

Speaking of PSU, one report said the best way to make the most out of the 6pin and 8-pin was to get a power supply with a single 12v rail. Is this true? Or would OCs over 1000 Mhz be limited by 6 and 8 pin power connectors?

 

[thilanliyan]

How does the Zalman VRM heatsink do compared to what you had previously?

Are you still using the 40% fan with custom shroud?

Check my 1st post in this thread...I linked to my mini-review of it. I got rid of the custom shroud and just have a 120mm fan pointed at the VRM heatsink.

 

[cbn]

Check my 1st post in this thread...I linked to my mini-review of it. I got rid of the custom shroud and just have a 120mm fan pointed at the VRM heatsink.

Thanks. I didn't see your edit earlier.

 

[Schmide]

That's probably why...it's the digital ones that get very hot and all the reference cards have them.

The digital ones are just the ones that self regulate and shut down, I can't imagine that they're any less efficient than the analog regulators, they're doing the same work.

 

[Schmide]

You run two HD4870s in Crossfire?

How do you make enough room in between the cards for the 80mm fan? (I am assuming the fan for the top cards VRMs is sandwitched in between the PCI-E slots)

My simple solution.

 

[thilanliyan]

The digital ones are just the ones that self regulate and shut down, I can't imagine that they're any less efficient than the analog regulators, they're doing the same work.

Do you run your VRMs without heatsinks and just point a fan at them? I'm pretty sure that would be impossible with the digital ones. They just put out too much power in such a small area that you have to sink them.

 

[mmnno]

Does internal complexity of the water block greatly factor into manufacturing costs?

The other day I saw a water block listed for hd5970 (that claimed to cool VRMs) but it was $149.

Internal complexity doesn't play too much into price. All full cover blocks are going to be in the $90-150 range. Here's a comparison of VRM coverage on all 5970 blocks - but note that the final version Dangerden block has been revised to run over the VRMs (no internal shots of the retail block yet) and those EK temps are probably not representative.

 

[Painman]

I have a 5850 (far cry from a 5970 VRM-wise, I know) but just for information, I cool it with an MCW60 plus stock baseplate, plus a series of 5 Enzotech low profile ramsinks placed over the VRM area of the stock baseplate, further spotcooled by a 60*10 mm Delta fan bolted to the card itself with some simple hardware store screws/nuts and fiber washers, and running @ 7 volts.

Works really well.

 

[thilanliyan]

I have a 5850 (far cry from a 5970 VRM-wise, I know) but just for information, I cool it with an MCW60 plus stock baseplate, plus a series of 5 Enzotech low profile ramsinks placed over the VRM area of the stock baseplate, further spotcooled by a 60*10 mm Delta fan bolted to the card itself with some simple hardware store screws/nuts and fiber washers, and running @ 7 volts.

Works really well.

What temp do the VRMs get to during gaming and furmark? Have you tried overvolting/overclocking at all and testing stability/temps? I'm curious to know as I will probably get a 5850 later on and do something similar to you.

 

[Schmide]

Do you run your VRMs without heatsinks and just point a fan at them? I'm pretty sure that would be impossible with the digital ones. They just put out too much power in such a small area that you have to sink them.

Just this dinky little thing.

If I don't run the fan and run OCCT they get super hot. With the fan, it's toasty but not extreme.