Can you use onboard intel graphics with a PCI-e video card installed?

[PingSpike]

I read something today that said a G41 based board with a pci-e card installed would not output to the hdmi/dvi ports during post. It also made it sound like once you got into windows the intel card would work as expected. Is this true?

I'd like to have intel board with an external graphics card installed and choose which video card to use at startup by switching hardware profiles (I do so now with a x1300 and a hd4850 and it works fine) but I want digital output. I don't have any such board to test at the moment. I'm interested in sandy bridge chipsets/cpus but also the G41 for an older PC I was thinking of upgrading.

 

[SunnyD]

As far as I recall, no. I believe that the PCIe x16 slot and/or the IGP share that PCIe channel, so you end up with one or the other, but not both.

 

[PingSpike]

Well that is crap. Is it the same with newer sandy bridge chips+boards?

 

[Meaker10]

Yes the board needs dedicated switching logic in order to pull that off and its only really found in notebooks.

 

[combust3r]

On H67 and Sandy Bridge you can have both integrated and PEG working at the same time. One will be primary for Desktop1 and second for extended Desktop2 ie. All you have to do is to select in BIOS - Onboard video - always and even though PEG is installed, HD2000/HD3000 will work also.

 

[PingSpike]

Thanks combust3r! I only really want to use one at a time (switch them through hardware profiles) but I don't want to take the graphics card out to do it. If they both show up in Windows and work I should be good.

 

[combust3r]

Yep, you can switch between the two and even disable the one you don't use at the moment. Works for me on the board in my sig.

 

[PingSpike]

It appears from some more reading around that this was sometimes possible on the G41 chipset s775 boards. It depended on the board I guess, with the PEG/IGP option not really working in most boards (it would just turn off the IGP, but setting it to IGP only would turn off the graphics card). I saw some one say Gigabyte in particular had a history of rerouting PCI-e lanes or something to allow for the concurrent use, although this was over a year ago and it seemed the boards that did this also limited the pci-e 16x slot to 4x electrical when they did so. More of a problem since G41 chipsets were only pci-e 1.0.

Anyway, the comments section on a recent Q&A with some intel guy about Sandybridge here on AT had him specifically stating that multimonitor support with discrete graphics cards and the IGP was possible. I would hope if it was dependent on motherboard implementation he would have mentioned that.

Thanks again for trying for me though combust3r. Its good to know its at least possible!