I am sorry to hear that have had issues with the Intel board.
The fact that your computer is working with onboard graphics, it means that it's operational; however, it sounds compatibility issue with the graphics card you have installed.
I need to know what the power supply wattage on your computer.
thanks for your reply.
I use a bequiet Pure Power L8 400W power supply.
This should be far enough for the used graphic. It also has the needed two 6-pol pcie power connectors.
I don't think the problem is power related since the fans of the graphiccards started to run every time I started the computer.
Since the newest BIOS shows a different behavior in recognizing I think it is a problem of the BIOS.
So another "Mysterium":
In the german c't-Forum I found a thread about an XFX Radeon R9 270 not working after standby or when the PC was out for a loneger period.
It was mentioned, that the Graphics option Primary Video Adapter "PEG" is selfresetting to "Auto".
With this in mind, and the hint that resetting might help I tested this myself:
I restarted the PC - my GTS 450 is installed. I changed the option Primary Video Adapter to "PEG".
F2 to BIOS options -> The Option is still "PEG". Shutdown.
I changed the GTS with the MSI R9 270x.
Start. The Mysterium: I got the FIRST and ONLY time a pic on my screen.
I went into BIOS - checked the PCI - there the MSI is shown with pci x16 and 8GH/s (the GTS only has 2,5 GH/s). I thought "Thats it".
Reboot - beep beep --- beep beep.
I tried several resets and other options. I even tried to Force the Primary "PEG" option. But nothing.
Still no picture with the card.
Since it worked once it can only be a BIOS and timing Problem of the Board!
Please make a working BIOS!!!
don't get me wrong, BUT the fact that the R9 270x graphiccard is running without any problems on an old MSI Board with an AMD Phenom II with 135W TDP and old 400W power supply, this answer ist not really satisfying.
I use an i5-4570 with 84W TDP, the graphic is designed with 170W TDP max. so we have in worst case around 300-350W (with RAM, HDD, etc.).
The fact with the newest bios it was recognized and I read about other users (in germany) that have the same chip (R9 270x) from different manufacturer (ASUS, Palit) working, I still think this is not a power related problem...
I returned the Board to my dealer to have an other in exchange. I hope he will give me one which is working correctly.