Running Crossfire/SLI in x16/x4 mode?

[hdpcgamer]

A lot of the fan noise is the PSU, it's also creating lots of heat which is really not helping. The hot air coming from it was raising my CPU temperature by almost 10 degrees. I guess you learn to check your power requirements before you buy the hard way.

I basically have two options. Buy a decent 750W plus PSU, or sell both cards and get hold of a better single card with the money. I'd like to get the PSU but I suspect that's an expensive option.

I know two 460's beat one 480, which is why I wanted that setup in the first place.

Regarding the temperature of your CPU raising by 10 degrees, are you sure its not the increase in heat from your dual 460s circulating inside your case that's causing the raise in CPU temps - your PSU should be pumping hit air out of the case via it's exhaust fan?

If you're happy with the performance of your dual 460s but want to lower the noise and temps, then I'd look at either trying to improve airflow further by replacing your case fans or upgrading your PSU to a decent quiet 750w or possibly an 850w PSU if you think there is a slight chance that you may crossfire/SLI two higher-end and more power hungry gpus .

 

[kristmace]

Has anyone done any tests with newer gfx cards (58xx or 6xxx) cards with a x16/x4 crossfire setup. On PCIe 2.0 the articles I've read showed a very negligable performance hit, but they are older articles not on these new cards.

Is this question directly related to your current setup?

Although I haven't found any x16/x4 crossfire/SLI benchmarks, going purely by the techpowerup 5870 PCI-Express Scaling benchmark, if you decide to add another 5850 to your motherboard with your existing 5850 occupying the x16 PCI-E slot and the other using the x4 slot, you should only be losing around 5% vs a full x16/x16 configuration.

Thanks. That's what I suspected. I think there's very little chance of me going Crossfire, but it's always good to know

 

[Blue160]

Regarding the temperature of your CPU raising by 10 degrees, are you sure its not the increase in heat from your dual 460s circulating inside your case that's causing the raise in CPU temps - your PSU should be pumping hit air out of the case via it's exhaust fan?

The PSU got almost too hot to touch. Yes the exhaust was hot, but everything around the PSU was hot as well, including the outside of the case. I've since found out that two 460's require 320W on the 12v rail, and my OCZ only has 300.

What PSU's would be recommended for 460 SLI? (obviously I should have been asking that question last week )

 

[Blue160]

Just to update.

I've decided not to sell the cards just yet. I've ordered a Coolermaster Silent Pro 850W to see if that helps. I'm not giving up on SLI yet especially after buying an SLI compatible motherboard specifically to run twin GTX460's. Will report back when it arrives

 

[hdpcgamer]

Just to update.

I've decided not to sell the cards just yet. I've ordered a Coolermaster Silent Pro 850W to see if that helps. I'm not giving up on SLI yet especially after buying an SLI compatible motherboard specifically to run twin GTX460's. Will report back when it arrives

Its great that you have decided to keep you 460s as they work out to being one of the best-bang-for-the-buck options you can get - you now have a set-up which is on par with the most powerful single GPU on the planet, the gtx 580.

The Coolermaster Silent Pro 850W looks like a great choice and the Pro range are suppose to be great performers with low noise.

Hopefully this will run quiet in your set-up and last you for awhile, and should you choose to upgrade to more power hungry GPU in crossfire/SLI in 2-3 years time, your new 850W PSU should be able to handle them without any issues.

 

[Blue160]

Update time

Coolermaster Silent Pro 850W arrived today. Installed, and put second GTX 460 back in.

I've had to tweak the fan profiles to keep temperatures under control, but everything is now running smoothly. I'm getting over 60fps at default settings at 1080p on Heaven 2.1, and mid 40's on the Crysis GFX benchmark at 1080p with absolutely everything on full.

The noise must have been the PSU, as I can deal with the GFX cards even at 90% fan speed. Thanks to hdpcgamer for helping convince me to keep them

 

[mame]

I've never tried crossfire/SLi. I've got a 16x/4x board (asus P55P7D-LE) which was just the board I bought. Never intended to have 2 GPUs. Maybe if my next card is ATI, I might keep it in mind

 

[hdpcgamer]

Update time

Coolermaster Silent Pro 850W arrived today. Installed, and put second GTX 460 back in.

I've had to tweak the fan profiles to keep temperatures under control, but everything is now running smoothly. I'm getting over 60fps at default settings at 1080p on Heaven 2.1, and mid 40's on the Crysis GFX benchmark at 1080p with absolutely everything on full.

The noise must have been the PSU, as I can deal with the GFX cards even at 90% fan speed. Thanks to hdpcgamer for helping convince me to keep them

Thats great news!

Its nice to know that you were finally able to confirm where most of the noise was coming from and that the PSU was the culprit because it was being pushed too hard.

Is the temperature of your CPU back to normal now and how much did the Coolermaster Silent Pro 850W end up costing you?

 

[Blue160]

New PSU was just under £100. It will hopefully last for many rigs to come

The CPU temperature is still raised but only by a couple of degrees, rather than the 10 plus previously. This fits with it being heat soak from the previous PSU. I've still had to lose my soundcard, but that's no big problem.

 

[phatboy]

Crossfire is a weird beast. My 16x4x setup really benefits in some things and I have near enough matched p45/x38 based systems with same bits. But in others it just falls over. Certain games like just cause 2, dmc4 and resident evil 5 you get a huge boost still!

Not trying to say its not without its flaws but if you can get the card cheap you still reap the rewards