I'm running a home server with the following hardware:
Everything was working great until I tried to add a discrete video card to the mix. More specifically, a Sapphire Radeon 5450 (PCIe 2.1 x16) in the PCIe x16 slot. After adding the video card, the LSI 3041E completely disappeared - it was no longer listed in the DQ77MK BIOS under PCIe devices, the LSI BIOS was gone, and all the drives went poof along with it. The Intel CT gbit NIC in the x1 slot still worked fine though.
So I shut down, pulled out the video card, and started back up, and voila - the LSI 3041e was back. I've looked through the manual & technical specs for the DQ77MK and nothing is mentioned about the x16 & x4 slots excluding one another, so I'm wondering whether this is a known limitation or possibly a bug. Thank you in advance for any help or advice.
I've got both cards working now but the "solution" required some very backwards-thinking.
I moved the LSI 3041e into the x16 slot and the Radeon 5450 into the x4 open slot. I won't be doing any serious gaming so bottle-necking the video card to x4 shouldn't be an issue. Both cards (and the gigabit nic in x1) get detected and are working properly.
You made a right choice.
Radeon 5450 performs equally "well" even if be plugged in a x1 slot as it is in x16, this card even can't beat Intel HD4000.