[Oberon75]

Built a new computer about three weeks ago. Here's what it's got:
i7-950 CPU
Asus Sabertooth x58
3GB Crucial Ballistix Tracer 1600 DDR3 (There's six more on the way here from an RMA)
EVGA GTS450 GPU
XFX 650w XXX Series PSU
Thermaltake SpinQ VT CPU cooler
Samsung 1.5TB HDD
Seagate 250G HDD
Lite-On Blu-Ray Drive
Windows 7 Pro 64-bit

Got a second GTS450 today. Installed the card, plugged in the SLI bridge, and fired up the computer... Waited for the notification that this computer is ready for SLI... nothing. Okay, maybe it doesn't do that notification in Win7. Opened up the Nvidia control panel, went to the 3D settings. It shows two cards, but nothing showing that SLI is enabled or any way that I can see to enable it. Went through the computer making sure all connections are secure, still no change. Removed the SLI bridge and uninstalled the drivers for the video cards, restarted, windows reinstalled the drivers, I updated them to make sure I have the latest release, restarted again, shut it down, replaced the SLI bridge, and turned it back on... still nothing!

The video cards work fine (I've tried my monitor on each of them), both PCIe slots are okay, what else could it be? Anybody got any ideas?

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Hi.


Sorry this post has endened up a bit messy.

You need to make sure the PSU is SLI certified. from what I gather you need 24amps on the 12v rail

This link may help with installing drivers.
Go to this page and follow the instructions > http://www.evga.com/...ase/Default.asp let me know how it goes. XXX

There pages are not linking right.
try again > http://www.evga.com/...spx?faqid=59062

Edited by iammykyl, 23 October 2010 - 03:47 AM.

[iammykyl]

Hi.


Sorry this post has endened up a bit messy.

You need to make sure the PSU is SLI certified. from what I gather you need 24amps on the 12v rail

This link may help with installing drivers.
Go to this page and follow the instructions > http://www.evga.com/...ase/Default.asp let me know how it goes. XXX

There pages are not linking right.
try again > http://www.evga.com/...spx?faqid=59062

Edited by iammykyl, 23 October 2010 - 03:47 AM.

[Oberon75]

The PSU is SLI ready. Made sure it would handle any foreseeable upgrades before I bought it. (Even if it didn't have the SLI ready logo, it's got one 6-pin and three 6+2-pin PCIe connections labeled for PCIe)

I'll uninstall/reinstall the drivers and get back with the results.

Thanks!

[Oberon75]

rechecked all connections, uninstalled and ran a clean install of the drivers (network interface and video card), and restarted. No SLI message, so shut it down and installed the SLI bridge. Powered back on, and same as before. One thought I had was is it possible that since the EVGA is factory overclocked and the PNY is not, could that be causing it, even if I have both set to the same clock speed?

[iammykyl]

Bad man!!

Which PNY card do you have?

Some more reading. This is an extract from the following article.
What happens if the cards have different amount of memory?
For ATI cards;
One of the cards will raise/lower its clock speeds to reach the other card's speeds.
For Nvidia cards;
Well it "was" like ATI with older drivers, but with new drivers its quite different.If you use 2(or more) Nvidia cards with different clock speeds in SLI mode,none of them will change their clocks and they will perform at their default clock speed. > http://www.tomshardw...-crossfire-faqs

Good article on SLI. > http://www.10stripe....express-2-0.php

Slightly older information but still interesting, > http://www.tomshardw...gpu,2678-6.html

[Oberon75]

The PNY is a standard GTS450. I got frustrated and was just about to return the PNY for a matching EVGA when I went to Nvidia's website to look for an updated SLI patch. Apparently the driver I had loaded (260.89, only a few days old) had just been replaced with 260.99. Loaded the new driver, restarted the computer, got SLI notification... All better. Just not sure why. From the update description there weren't any changes for the 450. But... It works!

[iammykyl]

Am sooo happy for you. Must have been very frustrating.

Thanks for letting us know the problem is solved.