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Have a UEFI with Radeon? Help me isolate a bug!

Last response: in Motherboards
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May 22, 2011 7:43:46 AM

I've been wrestling with a mysterious issue since installing my Radeon 6850 and it's been driving me crazy. Finally, (and no thanks to Asus or XFX) I believe I now know what's causing it...

Motherboards with UEFI seem to have an issue correctly displaying the BIOS/UEFI setup and logo/POST screens when running Radeon 6xxx video cards to a 720p or 1080p display. The OS works fine but boot screens can display garbled video, missing text, or just black.

What I'm wondering is if:

1. Others will experience the same symptoms with a similar setup
2. If the connection type matters (DVI vs HDMI etc)
3. If the brand and chipset (6850 vs 6870, 69xx, 6xxx, 5xxx) matters
4. If the motherboard BIOS version matters

If you have a 720/1080p display and can try booting with you computer connected via HDMI or DVI it would be very helpful to know your experience.

Thank you!
a b Ĉ ASUS
a b V Motherboard
May 22, 2011 10:37:10 AM

By protocol, when any HDCP type display is connected along with a VGA, the BIOS defaults to the DVI output and is blanked from the VGA.
If that's what you mean....
May 22, 2011 3:26:32 PM

Not sure I understand Noworldorder. Are you talking about a situation where multiple cables are connected to one card? The situation I'm referring to is a single card with a single HDMI cable to a 720p display.
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a b Ĉ ASUS
a b V Motherboard
May 23, 2011 10:30:35 AM

I believe the rule still applies; you could only test by running a VGA and testing.
a b Ĉ ASUS
a c 198 V Motherboard
May 23, 2011 2:34:35 PM

JoshNYC said:
Not sure I understand Noworldorder. Are you talking about a situation where multiple cables are connected to one card? The situation I'm referring to is a single card with a single HDMI cable to a 720p display.

What you are likely seeing is a scaling issue of the text being "stretched" to fit the larger display. Remember, the typical text screens that are displayed at boot were originally presented at 1024x768 (or lower) resolutions. When your drivers "kick in" later in the boot process, the screen resolution isn't an issue and all appears well.

Set your monitor/HDTV to 4:3 mode, as an experiment, and you should see a much clearer text screen at boot.

Also, using the VGA port and any adapter that allows you to use a VGA port will force your system to use an analog (vice digital) display. The VGA conenction is not optimal for higher resolution displays. Stay digital.

Good luck!
May 23, 2011 2:45:48 PM

I've tried 4:3 etc but it doesn't fix anything.

This isn't just an issue of stretched video but rather, garbage graphics (like a memory dump) in place of the American Megatrends and Asus logo screens. Also, attempting to hold DEL to open UEFI settings causes a complete lockup (green cursor visible, nothing more) or an instantaneous restart. Apparently there is some kind of resolution conflict and the motherboard doesn't know what to do so I'm getting corrupted graphics and restarting on the setup/POST screens.

Yes, VGA does seem to force display but as you're saying it doesn't make sense once the OS loads.

I believe this is a real bug in how the motherboard deals with certain displays when it comes to UEFI display modes.
a b Ĉ ASUS
a c 198 V Motherboard
May 23, 2011 3:00:26 PM

JoshNYC said:
I've tried 4:3 etc but it doesn't fix anything.

This isn't just an issue of stretched video but rather, garbage graphics (like a memory dump) in place of the American Megatrends and Asus logo screens. Also, attempting to hold DEL to open UEFI settings causes a complete lockup (green cursor visible, nothing more) or an instantaneous restart. Apparently there is some kind of resolution conflict and the motherboard doesn't know what to do so I'm getting corrupted graphics and restarting on the setup/POST screens.

Yes, VGA does seem to force display but as you're saying it doesn't make sense once the OS loads.

I believe this is a real bug in how the motherboard deals with certain displays when it comes to UEFI display modes.

OK, I understand better your situation. What make/model of display and motherboard are you using?
May 23, 2011 3:14:46 PM

Display is a Panasonic AX100U projector (720p native but can also do 1080i). Motherboard is Asus P8P67 PRO with a XFX Radeon 6850 (dual fan model). I've also tried another 6850 of the same make/model as well as an XFX 5770. All card exhibit the same behavior. I've also tried a GTX460 which does not exhibit this behavior. I believe the motherboard is requesting a very specific graphic mode that Radeon cards can't handle when going via HDMI to that display.
a b Ĉ ASUS
a c 198 V Motherboard
May 23, 2011 3:17:09 PM

All GPUs were attached directly via HDMI cable, correct? Also, what are your system's basic specifications? Last, is your BIOS up to date?

Seems this is a common problem with Asus mobos (using UEFI) when used with some ATI GPUs. I have seen lots of rants and angry users, but no solutions (on multiple forum sites, including Tom's). I took a look at your mobo manual and nothing sticks out there either. From my viewpoint, looks like Asus rushed out its UEFI implementation a bit prematurely without thorough testing to be completely honest. Sure are a lot of ATI/AMD GPUs out there.

Your options here are somewhat limited. You can try to get Asus to help, but I wouldn't count on it from what I have seen elsewhere. Same could be said of XFX. You could go with an Nvidia GPU, or you can live with the nuisance and just use the VGA and DVI/VGA adapter when you need to tweak your BIOS (others seem to be using this sub-optimal solution).

Check with Asus first, they may have a beta BIOS available to address the issue. Good luck!
May 23, 2011 3:36:31 PM

Correct. What corrected the problem was DVI->VGA via adapter. Also, Displayport to another display worked fine (2nd display didn't have HDMI so I couldn't test that). Clearly there's something with HDMI and certain display types and UEFI.
a b Ĉ ASUS
a c 198 V Motherboard
May 23, 2011 3:44:42 PM

JoshNYC said:
Correct. What corrected the problem was DVI->VGA via adapter. Also, Displayport to another display worked fine (2nd display didn't have HDMI so I couldn't test that). Clearly there's something with HDMI and certain display types and UEFI.

Understood. I have seen similar issues cleared up between PCs and HDTVs when the analog port was used. This issue here, as you correctly point out, seems to be confined to the HDMI interface (as evidenced by MANY other users at multiple forum sites like and including Tom's). See my earlier post for suggestions.

Good luck!
November 25, 2013 5:17:37 AM

Ok, this is a somewhat weird issue indeed. I am just starting to dabble with all this UEFI business and I am still seeing this as an issue well over 2 years later, even with a current bios update from 09/2013 - is this an issue with only HDMI and "digital only" DVI? or just multiple monitors connected in general? I'm playing around with all kinds of configurations, but I'm thinking that maybe someone in this thread as figure something out by now to either work around, or solve this issue?
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