X58A-UD rev. 1.0 and GTX 460 SLi

[MIK27CZ]

Hello,

my last (I hope) truble. SLI not working.

Must I set somethink in BIOS to use SLI? WIN7 see bouth, bouth works separately but no SLI options in nVidia control panel. (I have extra power cable to MB, SLI cable between cards, 16_1 and 16_3..).

Cards:
Gigabyte GXT460 1GB
MSI GXT460 768MB Cyclone

Thank you for help

[wazza300]

you have to install one card,install drivers,install second card,reinstall drivers,then sli should work

[MIK27CZ]

Still not working.

Some phtohos:
mik27 | nVidia SLI trouble ? rajce.net

[profJim]

Your problem is probably due to using video cards with different amounts of memory.
The Nvidia SLI FAQ says:

• Can I mix and match graphics cards with different sizes of memory?

When purchasing a second graphics card, you should try to match the memory size so that you are ensured full value and performance from your purchase. However, while it is not recommended, NVIDIA does offer the flexibility to run graphics cards with different sized memory by using CoolBits. Using CoolBits (value set to 18), you can force both of the cards to use the lower of the two memory sizes and operate them together in SLI mode. When dissimilar memory sizes are enabled to work together using CoolBits, the effective memory size for each card becomes the smaller of the memory sizes.

from: SLI | FAQ | GeForce (faq#c19)
The main SLI FAQ is at SLI | FAQ | GeForce

My GTX 460 SLI setup had no problems when using two slightly different cards where both cards have 1GB of video memory.
Let us know if using Coolbits solves your SLI problem.

[MIK27CZ]

1. Open regedit
2. Opened the tree:
Computer/HKEY_LOCAL_MACHINE/SOFTWARE/NVIDIA Corporation/Gobal/NVTweak
3. Inside of NVTweal added a 2 new strings
- Coolbits and Coolbits64 - both values = 18
4. Restarted
5. Bingo - Windows recognised as a SLI ready machine and the SLI option is enabled in the Nvidia Control Panel!

[profJim]

Glad to hear that SLI is now working.
Thanks for posting the detailed update procedure.