Multiple pcie-8371. One not detected

[jbell101]

Hi,

I have two USRP-2943Rs, two of the PCIe x4 expansion boards (PCIe-8371), and one host machine.

I have two available PCI slots on the host to plug these expansion boards into: a x4 and a x16.  Ironically, the board plugged into the x16 slot works fine, but I cannot get either board to show up when plugged into the x4 slot.

My PC is an XPS 8700 series (specs here)

Windows 7 64bit

I can see solid amber lights when the boards are plugged in without the USRPs on the other end.  Both turn solid green when the USRPs are on the other end.

I've narrowed it down to rule out bad cables, bad USRP boxes, and bad expansion boards.  Everything works perfectly fine plugged into the x16 slot, but not the x4 (even though, as mentioned, the LEDs indicate that everything is working).  When I plug either card into the x4 slot, nothing shows up in Windows device managaer.

The only thing I can think of is that there might be a conflict for multiple devices installed at once?  Is this a setup that is supported?  I'd like to run 2 USRP RIOs off one host machine.

And yes, every time I make a change, I completely shut down Windows, pull the power plug, and make sure the USRPs are configured and running before booting Windows.

--

Justyn

[alynch · Accepted solution]

The PCIe x4 slot in your computer is only wired as x1, which could be causing a problem.

This Dell support forum post discusses the issue: http://en.community.dell.com/support-forums/desktop/f/3514/t/19536759

[jbell101]

Well that sucks. Of all the things I would have thought it to be. Sorry didn't mean to make you troubleshoot the Dell computer itself. Thank you, though.