SLI GTX285 cooling problems?

[alcoholbob]

http://www.cpu3d.com/media/ima...1/i/19151/IMG_3431.jpg

Now how do you suppose the top card is even getting cooled? The fan is practically dead on top.

So I guess you could skip a PCI-E slot for more ventilation, but is it worth the drop in performance? (I've got an EVGA X58 mobo, so moving down a slot would mean 8x instead of 16x pci-e bandwidth).

 

[chizow]

The design of the shround and angling of the fan were specifically engineered to allow cooling in SLI. You'll most likely get some drop in temps if you move the 2nd card down a PCIE slot, but you can see from most reviews, both cards are being adequately cooled in SLI:

Tech Report: Various Temps at the bottom

Where you run into problems are if you have dual slot coolers that don't exhaust heat or sit right on top of each other, like the 4870 Asus Dark Knight and 4850 after-market coolers. Temps are nearly double in CF, and TR goes into quite a bit of detail about it here.

Single GPUs in this range (GTX 260/4870 and GTX 280/285) do start showing some constraints from PCIE 2.0 8x, in some titles, its not much but I'd probably go with slightly higher temps in SLI over an 8x slot.

 

[alcoholbob]

Okay, I'll try it. I've got a Coolermaster Cosmos case on order, it's supposed to be sound-deadening but cooling may be dubious...I wonder if my demand for silence and performance will be the end of me.

We'll see if the GTX285 SSCs on order catch on fire...

 

[yh125d]

This is my main concern about ever going with dual card setups. Perhaps I'm too cautious

 

[Hauk]

I'll think you'll be surprised by the cooling and fan performance. As Chizow said, the fan design allows for plenty of air to be pulled in. I'm running 285 SLI, fans are silent at default speed, and are barely audible with an open side panel at 50%. I run mine at 60% and am still very pleased.

Curious what default SSC fan speed is set to. Check what GPU-Z reports and let us know? The cards will be fine.. but do pay attention to fan speeds at full load. Cards will easily hit 80c, but at 60% fan speed, mine run around 62c at full load. Performance, cooling, and still fairly quiet. You'll be impressed..

 

[alcoholbob]

Hmm right now I have an 8800GT and I can barely stand the noise of it...at 35% really sticks out (80mm fan so when it speeds up its very audible)...I keep it at stock which is 28%.

I had an 8800GTS for a short while and it was definitely dead quiet, even for my standards. The only thing I'm worried about is (asside from cooling) given the proximity of the top fan to the bottom card, noise level will increase (kind of like cupping your hand over your mouth).

I'll let you guys know though, what the stock fan speed is.

 

[Hauk]

You've been tortured for too long. Those whiney little 8800 GT fans are like nails on a chalkboard. Put it this way, two 285 fans at 40% will be like, well, your GT being off..

 

[alcoholbob]

Just one question Hauk, how long do you typically keep your computer on each day?

My current system is a AMD 4400+, 2GB of RAM, 8800GT, a couple of hard drives, Corsair 550 PSU, Sound Card, and about 6 USB devices.

My PC is hooked up to the TV. Typically the computer will be on for 5-6 hours a day, although on weekends I might leave it on for longer--say 8-12 hours, watching TV or playing console games while the PC is just idling in the back probably 50% of the time, the rest of the time will be mostly watching movies or surfing, occasional gaming. Room temperature in general will be about 70-75C range, placed near a wall next to some consoles and AV receiver/amps although plenty of breathing room.

How well would a system with Dual SLI 285s be for media center (as in, longevity) with above average hours? Vista X64 with aero on as well...not sure if this will throttle the GPU speeds. I want to retire my current computer because I prefer an all-in-one setup and my current one is struggling with current games on the settings I prefer.

This is the first time I've built a rig that might be thermally challenged, hah, so I'm just a little worried. Thanks Hauk.

For reference the setup that's coming in the mail:
i7 920 (gonna overclock lightly, maybe 3.4GHz) w/ Noctua socket 1366 heatsink/fans
6GB DDR3 1600 (won't overclock)
eVGA X58 motherboard
SLI GTX 285 (eVGA SSCs)
300GB Velociraptor
2 x 1 TB WD Green
850W Seventeam PSU (I liked the 135mm fan ^^)
(+ sound card, and 6 usb devices)
Coolermaster Cosmos 1000 Case (it's stuffed with acoustic foam apparently)

 

[Hauk]

I use mine for gaming only and power it off when not in use so I can't comment on longevity, but can say you should be fine. Must keep in mind that for all uses besides gaming, card will run in in 2D mode or lower power mode. Expect top card to idle and operate in 2D at under 50c, bottom card 40-45c.

This is at idle with 70F room temp. Idle clocks are 300 core, 602 shader, 100 memory. 2D clocks are 400 core, not sure on memory, but the point is, except for 3D apps, these cards run very smooth and cool. You can bump fan speed to 55-60 to enjoy even lower temps. Compared to competitive cards offering this kind of power, these temps are excellent.

In addition, the power layout on these cards is excellent; longevity is certainly taken into consideration. The power components are cooled by air coming in through the port on the card's edge. This design also allows for better acoustics I imagine. You mentioned cupping your hand over mouth and what effect it produces. A large percentage of air will be flowing in from the edge port which helps.

Best advice is to consider default fan speeds, do they provide sufficient cooling for your tastes. You'll find that 55% fan speeds are still very quiet so if you want more cooling, even at idle and 2D, you have the option to adjust using Precision. Other piece of advice is case airflow. I bought an Antec 1200 for its size and the fact that I can run all fans on low and still have excellent airflow.

Keep us updated!