I think I need to run my second GTX 460 in the x8 pci-e slot. **Solved**

[Serradifalco]

Ok so here is the Readers Digest version. I installed the second MSI GTX 460 1GB card in my computer last night. I have 2 - x16 slots on my mb. Being dual slot designs, the cards are almost on top of each other. The temps on the upper card, because the fan is boxed in, are much higher than the lower card. I have the cards oc'd to 800Mhz. The lower card maxes out in the mid 50's under load. The upper card maxed out at 81c under load! My idea is to run the second card in the 3rd pci-e slot which runs at 8x. This will give the upper card some breathing room and greatly reduce temps. Will I lose much performance from the second card as a result? Thanks.

Solved:

I ordered a new, longer SLI bridge and separated the cards. Wow, what a difference! I now have them overclocked to 850Mhz with a slight voltage bump. The top card now maxes out at 70c and the lower one at 65c. This was with pretty warm ambient temps as well. Real world, when gaming, you definitely won't notice the difference between the x8 slot and x16 slot. You guys were absolutely right. If anyone needs a longer SLI bridge, EVGA has one on their website for $9.99 with free shipping. It is the flexible model as well, so you can use it to span different distances. Thanks.
I will shoot for 900Mhz before this is all over!

 

[TheUnk]

You won't lose any real performance..

Are you sure the position is the issue though? Have you tried placing the top card in the bottom and checking temps?

I have two 480s and the top one does not get any hotter than the bottom except by a few degrees. Then again they both run at 90s under load =p

 

[Serradifalco]

You won't lose any real performance..

Are you sure the position is the issue though? Have you tried placing the top card in the bottom and checking temps?

I have two 480s and the top one does not get any hotter than the bottom except by a few degrees. Then again they both run at 90s under load =p

The top card was the original card in the computer and it was running cool until I put the second one below it. I know it is definitely the position. The top card can't possibly cool properly as the air flow is being restricted by the one below it. Thanks.

 

[dug777]

81'C under load should be no worries I would have thought, unless it's making the fan ramp up and annoying the hell out of you

In most of AT's testing the Fermi chips seem to load up quite warm and nvidia seems fine with that

 

[Serradifalco]

81'C under load should be no worries I would have thought, unless it's making the fan ramp up and annoying the hell out of you

In most of AT's testing the Fermi chips seem to load up quite warm and nvidia seems fine with that

I don't know. It just bugs me that the temps are over 20c higher than they could be. It is just extra, unnecessary heat. Thanks.

 

[Termie]

I don't know. It just bugs me that the temps are over 20c higher than they could be. It is just extra, unnecessary heat. Thanks.

This article will put you at ease about using that x8 slot. In short, it doesn't make a difference:

http://www.hardocp.com/article/2010/08/16/sli_cfx_pcie_bandwidth_perf_x16x16_vs_x16x8/

 

[dug777]

I don't know. It just bugs me that the temps are over 20c higher than they could be. It is just extra, unnecessary heat. Thanks.

My bad, nvidia recommends keeping a slot clear, according to AT:

http://www.anandtech.com/show/3836/msis-geforce-n470gtx-gtx-470-sli/6

Still, your temps shouldn't harm anything, but if you wanted to sort it could you ghetto-setup an 80mm case fan to rectify the airflow issue?

With my 4850 the non-reference hsf didn't have VRM cooling, which was fine for stock but no good for 800Mhz core, so I stuck dinky little RAMsinks on the VRMs then used monfilament fishing line to strap an 80mm Noctua to the PCB. Worked a treat and since my case was closed, who was ever to know?

EDIT: As has been said, the x8 slot won't hurt your performance any, so that's your easiest solution

EDIT2:

These lines scared the hell out of me:

With the partially obstructed GTX 470 card exceeding 90% of its top fan speed, the SLI combination is second only to the GTX 480 SLI.

Zomg, if the fans on those are anything like the one on my reference 5850 (whoch I have never seen over around 41% left on auto), that's one freakin' noisy leafblower!

 

[Serradifalco]

This article will put you at east about using that x8 slot. In short, it doesn't make a difference:

http://www.hardocp.com/article/2010/08/16/sli_cfx_pcie_bandwidth_perf_x16x16_vs_x16x8/

Good stuff Termie. That is just what I was looking for. Plus, I can oc my cards even higher if they are running cooler. That is the other issue, the heat limits my oc headroom. Cool. Now I just have to find a new SLI bridge. Preferably a longer, flexible one. Any ideas?

 

[Grooveriding]

It's a minimal difference, I've benched it on my system and I lose about 3fps putting the second card in the x8 slot.

I had to do the same thing, as with my cards side by side the top one would get up to 95C at times, even saw it crack 100 a couple times.

 

[Serradifalco]

It's a minimal difference, I've benched it on my system and I lose about 3fps putting the second card in the x8 slot.

I had to do the same thing, as with my cards side by side the top one would get up to 95C at times, even saw it crack 100 a couple times.

Wow buddy! Nice puter. Thanks for all the input guys. This forum is the place to ask questions. You are all over it. Thanks again. You too dug777. You went out of your way to be accurate. Cheers to you buddy!

 

[Serradifalco]

Issue solved. Read above.