Asus A8N-SLI Premium: Not detecting SLI

I replaced my dying DFI board with an Asus A8N-SLI Premium from eBay, and I haven't been able to get SLI options to show up at all. Since it didn't come with a bridge, I figured that was the issue, even though nVidia drivers have been supporting bridgeless SLI for a while.

But now that I have ordered the SLI bridge, and have put it in, it still doesn't detect SLI, no matter which setting I choose in the BIOS. Basically when I look in the nVidia Control Panel (both new and old, using a registry hack to get it to show), the option for SLI simply isn't there, as if the chipset didn't support it at all.

This is using Windows Vista 64-bit, with ForceWare 169.09.

I've already ensured that both cards worked individually, in each slot of the motherboard. In each case, it POSTs fine, gets to Windows, and is detected by GPU-Z normally. However, if I put both at once, the second one might as well not exist. Plugging the monitor into it gets no signal. I know the cards can work in SLI as I already used them with my old board.

I had BIOS version 1009, so I figured updating would help, however it's not any better with 1303.

Already searched around for possible compatibility issues between GeForce 7800GTXs, A8N-SLI Premium and Windows Vista 64, and couldn't find anything glaringly incompatible.

Any insight?

Did your bios show this?:

http://www.viperlair.com/images/reviews/cpu_mobo/asus/amd/s939/a8nslipr/bios8.jpg

The AI Selector in the bios?

" The last thing of note is the SLI Configuration page where you can choose to enable or disable the EZ Plug warning. This screen also indicates whether the system is in single video card mode or SLI."

That's essentially it, though there's also a SLI Broadcast Aperture option, and the AI-Selector is set to Dual Video card as it should be. Setting it to Single sets the PCI-Express speed to x16, but apart from that does not change the SLI side of things.

You try older video card drivers? Also have you swapped video cards around?

With Windows Vista 64, can't go very far back in time driver-wise -- the first ones are plagued with bigger problems than these. I did try both the beta and current WHQL ones however. Also, before formatting to install Vista, it was running XP with some iteration of the 100 drivers, and had the same issue not detecting SLI.

Already swapped the cards around countless times, though not with the bridge, might as well give that a go.

Edit: No change.

This may be a dumb question, but that board has a little chip on it held in by a clip. To enable SLI, you have to take out that chip, flip it around, and reinstall it. Have you done that?

I've certainly done nothing of the sort, I assumed it was a jumperless version of the A8N-SLI Deluxe as it was intended to be. The Deluxe one does have a card like you're describing, are you sure you're thinking of the Premium?

Deluxe:


Premium:

Wow, I like that Premium. I've never looked closely at one before.

If your Premium version doesn't have that card, then pay no heed to my post. Apparently only the vanilla (mine) and Deluxe versions of the A8N-SLI have that card.

Well lets recap:

Swapped drivers: Check
Flashed bios: Check
Swapped cards around :Check
Swapped OS'es : Check
Both video cards working properly : Check

Not sure, but where exactly did you get the SLI bridge from? It could be one of 2 things:

A) The SLI Bridge may be faulty, but that's uncommon
B) The Mobo is faulty

Not anymore options left i'm afraid.

Doubt it's the bridge, as it'd still see the two cards and allow SLI, just at a lesser performance. Well, time to contact ASUS. Thanks for the ideas. =)

Could anyone with CPU-Z and a nForce4 SLI board post their mainboard tab? I want to know how much information it tells about what kind of nForce4 is present. I'm starting to think that since this board is refurbished, Asus could've mistakenly swapped the nForce4 SLI chipset with a non-SLI one.

Even though I could mod an Ultra into a SLI with a lead pencil, I'd rather double check before taking it apart. =)