Performance drop with SLI (GTX 460)

[Tor77]

Hi people, just wanted to check if anyone here has experienced this. I did a search but only articles and news showed up.

Problem is simple: Bought a second EVGA GTX 460 Superclocked (1GB) card to ensure top performance in BF3. I ran TessMark 0.3.0. to see how the performance was improved. Turned out it wasn't. I am getting higher performance from a single GPU than in SLI. What gives?

Here's my rig:

Mobo: ASUS P7P55D-E Premium
Graphics: 2xEVGA GeForce GTX 460 1GB PhysX CUDA in SLI
CPU: Intel i5 760 Quad
Memory: Corsair 2x4GB DDR3
HDD: Intel SSD x25 80GB
PSU: Corsair TX 850W
OS: W7 64 Pro build 7600

I have uninstalled the old NVIDIA driver and ran DriverSweeper in Safe Mode before installing latest driver (280.26) before testing. Both cards are installed in PCI-Express 2.0 x16 slots.

I read somewhere that CPU's can be the bottleneck when it comes to SLI. Still, I would be surprised if an i5 760 would cause this.

TessMark with SLI enabled:

[img=http://s4.postimage.org/1t4qhjxyc/SLI_after_installing_new_drivers.jpg]

TessMark with SLI disabled:

[img=http://s4.postimage.org/1t4tsmmxw/SLI_OFF_after_installing_new_drivers.jpg]

Any tips/help appreciated! Thanks

 

[iam2thecrowe]

use something other than tessmark. play an sli compatable game and use fraps.

 

[Tor77]

Brilliant mate, I'll give that a try. Thanks!

 

[benski]

Try Unigine Heaven, it is a nice tesselation heavy benchmark that works with SLI.

 

[Tor77]

Thanks @benski, I actually did and I think FPS was around 45-50 with 4xAA and tesselation running at 16(?), if my memory serves me correct (SLI enabled).

Cards heated up properly, though, almost reaching boiling point temps

 

[psyxix]

This is an obvious case ventillation problem!

 

[Tor77]

How can I get the case temp down? Only thing I can think of is opening the case when gaming as I have two 12cm fans in the cabinet + CPU cooler, of course.

Any tips on cooling down the "general" temperature? I've never ventured much outside standard PC building before so this is kinda new to me.

 

[benski]

A side fan blowing across the cards can help if your case supports it. Just how hot are you talking about? If they get over 90 degrees I would be concerned, less than that under a heavy benchmark load is probably ok since regular gaming wont get them that hot.

You can try downloading MSI afterburner and setting a custom fan profile if they are getting too hot for comfort.

45-50 fps on heaven is pretty good, I have a single 460 in my HTPC and I think I remember it being around 30 fps at those settings. My heavily overclocked 465s get 53 fps.