R9 290x Crossfire VRM Cooling

[Maverickunna]

Preamble:
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I created a AMD R9 290x Crossfire rig with a stock watercooling system for each GPU. I used the "Arctic Accelero Hybrid II 120" to cool down the GPU. The first edition is out of stock now and I didn't get a classic Accelero Hybrid with active cooling fan.
The new GPU Coolers came with a massive passive heatsink placeable on the backside of the card. With this setting I am blocking 3 PCIe slots - one above the card and 2 downsides (Water tubing).

With this new setting I'm able to cool down the GPU to about 65°C on full load instead of 95°C @ 75% fanspeed with the Twin Frozer air-cooler.

Problem:
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BUT! The VRMs runs @ 76°C in 3DMark - relatively cool so I tried to use Furmark to get MAX temps out of each card and monitored it with "GPU-Z"

I was shocked to see the VRM temps reaching 120°C after a few minutes - this was when I stopped the test manual. I don't have other games tested yet but are those critical temps normal with Furmark? Or what can I do to lower it?

It would be a pity to plug another active cooler under the PCB it is a nice and silent setting so far. How can I see those temperatures in Furmark - are they just reachable in this Benchmark or could it be that I reach those limits in ordinary games too.

 

[RnRollie]

i wonder... it would be a LOT easier to flunk these Hybrid II on ebay and give more peace of mind by just getting these things:
http://www.swiftech.com/mcr-x20-drive-rev3.aspx
and
http://www.swiftech.com/KOMODO-R9-LE.aspx
OR
http://www.performance-pcs.com/cata...t_info&cPath=59_971_240_579&products_id=40683


Yes, compared to an accelero hybrid, the price is a bit steep... but... an accelero, an extra bracket, an extra fan, bits & bobs and still not sure if it can keep the VRMs heat at bay...

From what i've seen the Hybrid II is flawed... sure, it 'll work well on average cards, but for the top-end it feels like it falls short and brings up too many uncertainties... which is probably why its "very competitive priced". I wouldn't trust my hi-end card to it.. maybe if they did a Revision 2 to address some of the issues.
Meanwhile, a full-block + dedicate rad/pump/res combo solution like above would be a far better & safer solution.

Of course... you actually can mod something like a H100 to drive the GPU full coverblock only - easy enough to do... but why use inferior products?

PS: Furmark is incredible harsh, it is doubtfull that you ever get this strain in "real life". Then again you'ld need something that can monitor everything while running HEAVEN benchmark. Check out Guru3d, they might have some nifty software for that http://www.guru3d.com/

 

[Maverickunna]

It is a risen system you have to know. First I had just a GTX 780 (accelero hybrid classic cooled with active fan for VRM and memory) with an I7 3570K watercooled by H100i then I changed to I7 4770K - with R9 290x MSI edition with Twin Frozer and watercooled it later by the "Accelero Hybrid II 120" because the classic model is out of lifetime. I added a 120mm fan on the bottom of the card to cool the VRMs

after that I bought a 27" Monitor with 2560x1440 resolution and realized I had terrible framedrops and losses about 40% of performance. So I upgraded to Crossfire and got a XFX R9 290x CORE edition. I attached the Twin Frozer to this card but it reached 95°C within minutes in Crysis 3, it starts to clock down and speed up the fans to noisy 75% to reach safer 93°C.

So I bought another - better cooled tower - the ANTEC Lanboy Air and added 4 120mm silent fans controlled to 1000 rpm. With 9 fans inside I thought I would get enough cooler airflow inside while pushing the heat out of every hole.

But I only bought some more time in silence - so I added another Arctic Accelero Hybrid II to the second R9 - with success - GPUs are running @ 65°C (full load) very silent @ fixed 55% fan speed on the radiator.

I started Furmark then and was shocked by the VRM heat rising so high.

I bought the stock water-cooling sets because:

1. It was cheaper than custom cooling
2. It is maintenance free no water refill or change
3. It is better for transport
4. It should be a better cooling performance to cool down every card by its own radiator
5. Nearly no risk to get a water leak because it is a compact, closed system - (pre-build)
6. I already had a CPU watercooling block (H100i) and spent 100 bucks before.

Sorry if I sound strange - English is not my native language

In Crysis 3 the VRMs seems not to gain higher than 85°C - why pushes Furmark the VRMs to that dangerous limits?

 

[Supertrucker]

Dont use furmark, for anything. It is lousy as a stability test, and it pushes video cards so far beyond what they will see in any other scenario that it is a pointless metric.

On a stock 290x, that giant heatsink on the back looks like nothing more than a waste of space, to me. The backs of my cards are bare, with ek full cover blocks on the front, and my vrms dont ever hit 50c.

Do you have any kind of heatsink on the vrms at all? You need one if you dont. Doesnt matter if its a cut up old cpu sink, or something like http://www.newegg.com/Product/Product.aspx?Item=N82E16835708011 designed specifically for vrm cooling. it doesnt take much to keep vrms happy, but you need something.

 

[Maverickunna]

The gigantic passive heatsink was designed just to cool the PCB, memory and VRMs from the backside - it was the "innovative" change to the old active cooling from the former cooler-model. I had to put cooling-pads on the PCB-backside where Memory and VRMs are placed.

In addition I have some thermal adhesive (thermal glue) and some small aluminium heatsinks from the former cooler I can add on the top-side perhaps. But I don't know if it will be enough without an airflow that cools the heatsinks.

And I think I had to add, -

The R9 290x by MSI is clocked @ 1030 MHz on stock and was pushed a little to 1050 MHz by myself.
The R9 290x by XFX is clocked @ 1000 MHz on stock and was also pushed to 1050 MHz by myself.
Both was given a power-limit +50% and the radiators where cooled by the 120mm stock Arctic fan fixed at 55% speed.

GPU temps where at 64°C (upper card) and 58°C (newer, lower attached card) in full load in 3DMark 2013 instead of the 95°C
top temps where 72°C on the top card and 65°C in Crysis 3 maxed out in 2560x1440p

What I think is a very nice and cool temperature for this power-sucking and hot burning peace of hardware.

 

[Supertrucker]

Yeah that heatsink isnt gonna do jack for the vrms while on the backside of the card. Its about as innovative as putting the cpu cooler on the back side of the motherboard.

You dont need a lot of airflow to keep the vrms cool if they have heatsinks on them. Even just a single low speed quiet 120mm fan that you can hang at the end of the two cards will do wonders.