Need advice for what slot to use

[badoosh]

I am looking to buy a second MSI HD 6950 graphics card but if I use the second x16-x8 slot on the mobo I have no room for cooling. So my question is can I use the "dedicated physix" slot x4 for the second card with no issues or will I have performance issues?

I do not want to have to buy a new mobo to crossfire with better cooling, if I do I will be going back to Nvidia!

Here is a pic of the mobo

 

[Helltech]

Are you absolutely sure that last slot will be x4? I find that hard to believe.

If it really is x4, you don't want to put it in there no. The 6950 is a higher end card, the x4 bandwith will eat away at its performance.

 

[mdd1963]

Most folks claim there is no noticeable difference in using a dedicated PhysX card these days, in that any card in the GTX570/6950 class does well without one....

I'd abandon the idea as an unneeded expense....

 

[4745454b]

Whats wrong with using the normal slot? You state you'll go back to Nvidia if you have to buy a new board, so I doubt the problem is a cooling issue. Their cards run hotter then AMDs so whats the real reason? I don't think you want to use the 4x slot. 16x/4x on PCIe 2.0 is usable, but you tend to see lower scores throughout.

I'd get the second card and put it in the slot your supposed to. Make sure you have some good cooling/case fans going.

 

[badoosh]

The real reason is if I were to crossfire a second card there wouldnt be any space between the two cards for air intake on the first card. But I found out all the slots are x16 no no issues there.

 

[4745454b]

I was trying to point out that even if you went with Nvidia, you'd have the same problem but with hotter cards. Either way you have limited space between the cards, or you need a new board. Glad to see that third slot doesn't run at 4x.

 

[jockey]

If your case has a spot for a side fan, add one. Also, arrange your HDDs so that the front fan has clear air flow to the GPUs. The top card will be the hotter runner, so keep air on that one.

 

[badoosh]

I want to liquid cool my vid cards but don't want to spend $600 to do so. Thanks for the good answers! One last thing I have the Coolermaster HAF 932 case so air cooling is no issue but I want to mount a rad on the top but not sure it would fit. The rad is a Swiftech or EK 4x120mm, the reason for the large rad is I plan on OC'n my i7 950 to well over 4.5Ghz...can a single 4x120 fit or should I use just a single 3x120 or 200mm?

 

[jockey]

That is a big case, don't see where you would have an issue.

 

[badoosh]

I have heard you can't mount a 4x120 rad in the HAF 932 but however you can mount a 3x120!

I plan on modding and refabricating the front panel I/O for just power-reset with a flow meter since the usb's fail to work aswell as the audio.

I have already painted the case aswell as the acsents.

This is my case