Use 2nd sli pci-e slot for other type card conflicts with win7?

Trying to use the x8 slot on M2N-SLI for Asus U3S6 (USB 3.0 and SATA 600).
It works fine with a 2 monitor setup under XP, but not under win 7.
My guess/deduction is that win7 tries to determine what monitor(s) are attached to the U3S6. When booting win7, the monitor will show bios, the U3S6 is recognized, but the login screen will fail to appear. If I attach the second monitor, the login screen will appear on that monitor and the first (primary) will stop working, and can't be revivied during the session using either NVidia control panel or windows screen resolution.
I can still use two monitors on win7 by effectively disabling the U3S6 in bios, selecting for SLI config: single graphics card.
Under XP I can use the combination of dual monitor and effective USB3 (HD rates > 100 MB/s). Under win7 I have to choose between dual monitor and USB3 (SATA 600 not yet in use).
Thanks for any ideas / help / comments.

CPU: AMD phenom II X4 945
GPU: NVidia 275 GTX
win 7 64 ultimate

Not sure what that's about but you should certainly be able to use other cards in those slots and Windows will pick it up if a driver is supplied.

As you see in my system I have a Creative X-FI soundcard plugged into the PCIE slot at the bottom. I have an Intel board. Maybe AMD boards work differently? Don't think so, but....



Anyway you need to read the owner's manual for your motherboard to see what it says about using those slots.

sygnus21 said:

Not sure what that's about but you should certainly be able to use other cards in those slots and Windows will pick it up if a driver is supplied.

As you see in my system I have a Creative X-FI soundcard plugged into the PCIE slot at the bottom. I have an Intel board. Maybe AMD boards work differently? Don't think so, but....

Anyway you need to read the owner's manual for your motherboard to see what it says about using those slots.

Thanks for the advice.
1) the system does recognize the card and has a driver for both Marvel 91xx SATA 6G controller and for USB (see attached devices.png)
2) The mobo manual list "Other PCIe devices (X8, x4, x1)" under non-SLI mode
3) The problem is that I cannot use my second monitor in this configuration (i.e. under win7 64 ultimate SP1; the same setup will work under XP 32bits)
4) have to admit that my old mobo is not on the U3S6 compatiblity list (see e.g. Asus U3S6 USB3.0 weird quirks - Other-Components - CPU-Components however, it evidently is compatible enough to work...
So, I'm not prepared to give up yet and still believe it is a win7/driver issue. I don't suspect the nvidia driver terribly, since a similar driver will work under xp. But I did post on Nvidia as well, no luck so far.

janhec said:

3) The problem is that I cannot use my second monitor in this configuration (i.e. under win7 64 ultimate SP1; the same setup will work under XP 32bits)

Sorry but I'm still a little confused here. You'll have to provide a little more information on the setup that allowed dual monitor under XP, but not under 7.

janhec said:

So, I'm not prepared to give up yet and still believe it is a win7/driver issue. I don't suspect the nvidia driver terribly, since a similar driver will work under xp. But I did post on Nvidia as well, no luck so far.

Windows 7 is not XP. And XP drivers won't work under a Windows 7 OS.

Thanks. Glad to know I'm not the only one confused. Hopefully the OP can clear things up.

Hey guys,
The monitors are both connected to the GTX 275. I hope suggestions like I would connect a monitor to USB 3 are not serious. One is connected through a DVI-VGA adaptor (you know, DVI has both analogue and digital in the spec). This does not matter in my view.
So
Mobo: M2N-SLI
CPU: AMD phenom II X4 945
GPU: Nvidia GTX 275 with two monitors attached
Monitors: Samsung 2443BW and 204B
Memory: 4 GB DDR2
OS: Win 7 64 ultimate SP1
HD's 3 disks on SATA 300, 2 in RAID 0 and a single disk, nothing on SATA 600 of U3S6.
U3S6: USB 3.0 is used for connecting Samsung 2TB hd (has USB 3.0 interface).
Audio: SB audigy

There are no errors shown in device manager.
It looks as if under win 7 the recognition of the main monitor is blocked by the U3S6. Bios etc. is shown on the monitor, but the login screen is not. If the U3S6 is disabled, the monitors function correctly.