HD 5750 incompatible with older PCI-Express 1.0 MoBo?

I recently purchased an HD 4850 ... which died within an hour. So, I've now replaced it with a 1gb HD 5750 by Sapphire.

I got the card yesterday, and my system will not boot with the card installed. The readout on the MoBo says that the BIOS should be taking over, and it just stalls there (POST code 9.0). The motherboard is an ABIT AT8. It's an older board, but with 2 PCI-Express 1.0 slots on an ATI Xpress 200 chipset.

I have verified the function of the video card on another machine and it works great. The card is in the correct PCI-Ex slot and the "shadow" card is in place for single card function.

For the install on my machine, I've:
Cleared the CMOS
Verified BIOS settings
Tried to run with my old card in the secondary PCI-Ex slot (obviously this wouldn't work ... just to test if it would boot)
Reseated several times

I'm waiting on a response from ABIT since no one answered the tech support line after 45 minutes yesterday.

I was under the impression that PCI-Express 2.0 cards were backward compatible with 1.0 and 1.1. Maybe the board doesn't like the 1gb memory on the card? The newer chipset?
13 answers Last reply Best Answer
More about 5750 incompatible older express mobo
  1. have u try update your mobo's driver?
    and yes, obviously, PCI-Express 2.0 cards are backward compatible with 1.0 and 1.1.
  2. I can try, but there it only 1 driver update for the board from a few years back. I'm pretty sure it's been applied. I should have the latest BIOS and drivers, but I'll double check. Thanks.
  3. I'm Having very similar issues with my sapphire 5770 - i get no signal on the screen and the pc doesnt seem to do anything but sping the fans - i have taken it into my local computer specialist so I will let you know what he thinks. i have a different mobo from ASUS but its also pretty old. Cards should be backward compatible but its looking less and less that this is the case with this card...
  4. I updated the motherboard drivers with the latest release of legacy drivers from ATI. None of the drivers or applications from ABIT seem to work on Windows 7, so that was a no go.

    Still no boot. Same lock at POST with the 9.0.
  5. How old and how much wattage is your power supply. Your new GPU may not be getting enough power.
  6. Its an Antec modular 550w.
  7. i'm having similar problems. I just bought an ati hd 4670, which is pci 2.0. My board has a pci 1.0 slot. its and ecs socket 754 running an athalon 3200 64 bit. my computer is dragging bad, and has rediculously slow response. but if I put my old pci 1.0 nvidia card back in, all runs well. this makes no sense whatsoever
  8. I've also got a very similar problem with my XFX 5770 that I just got, my PC won't even get as far as POST'ing with it in, all it does is sit there and turn fans on and off and flash the lights of my DVD drives at me. Ive got a 550W psu (ATI's website recommends 450W+) and an asus ASUS P5N32-SLI SE Deluxe mobo with core 2 duo E6700. Works fine with my old 7900gtx instead.
    Thought it must be an issue with one of my components, but perhaps its a more fundamental problem if others are having similar issues?
  9. I can confirm that i'm also having this same issue with a Radeon HD 5850 and an ABit AT8 32X.

    If i perform a CMOS reset, after replacing the battery the system will get to the BIOS screen once only, and then any subsequent restarts cause the board to hang, displaying error code 90.

    This makes me sad :(
  10. Touring Bouble

    Some ATI Xpress 200 have built in Integrated graphics card. It is the default GPU unless disabled. You have to disable or change priority on boot up at BIOS level. You may need to boot up on PCIE based GPU which is your 5750.
  11. Best answer
    Incidentally, after doing some trawling around the net for more information on this issue, it appears that the Radeon HD 5xxx series will not work with pretty much any PCIe 1.0 or 1.1 slot, with the odd exception (see for more information on this).

    Manually resetting the CMOS before each boot seems to work on some boards, although obviously far from an ideal solution.
  12. Thanks for the clarification smimon. That seems like the issue.

    And my MoBo does not have integrated graphics.
  13. Best answer selected by touringbubble.
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