I have a Shuttle SG31G2 that has an Intel G31/ICH7 chipset, one PCI slot, and one 16x PCI Express slot. I want to add a better gigabit NIC to it, and the PCI slot is already in use by a SATA card. According to this this diagram of the chipset, the x16 PCIe slot is connected differently than the other PCIe slots.
If I put a non-graphics PCIe card into this slot, will it work? Has anyone tried this? This may seem like a dumb question, but this guy was not able to do it on a Shuttle SB81P with a Intel 915G/ICH6R chipset, which has a similar diagram.
Results
This configuration worked for me. I was able to install a network card in my "graphics" PCIe slot, and my onboard video continued to work (at least through the VGA port, the DVI port could have been disabled, but I don't use it so I don't know). This behavior appears to depend on the motherboard, so you may not have the same results with yours.
Best Answer
January 7th 2014 Edit
I currently have a PCIE x4 Intel I350 NIC in a PCIE x16 slot meant for graphics on a Intel DH77DF motherboard working without a problem.
The original post below stating that "as long as it fits it should work" still stands. It's still possible that some motherboard manufacturers have a PCIE x16 slot that won't accept anything other than a graphics card. I think this only happened in the early days of PCI Express, and modern motherboards (say Core 2 and newer, and definitely Core i-series and newer) are pretty flexible in what you can use the PCIE x16 slot for.
Also, make sure you have on-board or on-chip graphics, or a video card somewhere. Most motherboards won't boot without video. Although, sometimes you might be able to configure the BIOS to ignore the lack of video and continue booting.
I figured I'd return to clarify my answer after encountering this very situation myself :)
Original Post
Initially I'd say there's no real difference between the PCI-Express slots and as long as it fits there's no problem.
However, the problem is if the PCI-Express slot is specifically labeled for video card. The tomshardware link shows the user placing the TV Tuner card in his second slot, not the first. The first slot (in your case, your only slot) might be graphics only.
Some point to yes. Some point to no. It's hard to tell and seems like it's up to how the motherboard manufacturers decided to integrate the chipsets.