@Lbr thanks for the help,,,
Mine is revision 5 the mobo ....
I am waiting some x16_x16 powered risers(flat) from ebay the ones with the blue tape ..
-Do you think they will work or i will have to order the ones that you say (x16_x1 powered risers(flat)) ?
- I want to attach 5 or 6 HD7990 i don't know if i can put so many ...
4x7990 max. afaik. That is 8xGPU. Use Windows 10.
As for x16_x16 vs x16_x1.. well.. I dunno. I've tried x16_x16 risers also and they did work. However I've never used x16_x16 in production, that is running rigs 24/365. Only x16_x1.
Anyway, your issues.. seem weird. Technically there is no difference between usb risers and common x16_x1 powered risers.
However, I've seen vide cards which just refuse to work with any riser.
And.. since I can't get hands on your system.. sadly I can't help.. But do try setting pcie to 1.1 speed(I can't find it in the manual.. maybe it does not exist?), setting primary GPU to one of the x16 slots and plug GPU there. Only one GPU.
Play with those -
Manual, page 47
Init Display First
Specifies the first initiation of the monitor display from the PCI Express or PCI graphics cards .
PCIe 1 Slot Sets the graphics card on the PCIEX16_1 slot as the first display. (Default)
PCIe 2 Slot Sets the graphics card on the PCIEX16_2 slot as the first display.
PCIe 3 Slot Sets the graphics card on the PCIEX4_1slot as the first display.
PCIe 4 Slot Sets the graphics card on the PCIEX4_2 slot as the first display.
Manual, page 45
Full Screen LOGO Show
Allows you to determine whether to display the GIGABYTE Logo at system startup. Disabled skips the
GIGABYTE Logo when the system starts up. (Default: Enabled)
Manual, page 45
Display Boot Option Control
Allows you to select whether to enable the UEFI or legacy option ROM for the graphics controller.
Disabled Disables option ROM.
Legacy Only Enables legacy option ROM only. (Default)
UEFI Only Enables UEFI option ROM only.
Legacy First Enables legacy option ROM first.
UEFI First Enables UEFI option ROM first.