Default underscan not zero on win7, cat 10.8 & HD 5830

[streetfighter 2]

I've had this problem ever since I bought a new computer. My mobo has an onboard HD 3300 and whenever I booted the computer the underscan was set to a nonzero value which was annoying (to say the least). Then I got an HD 4350 and the same thing was happening whenever I booted. Then I got an HD 5830 and the same bloody thing happened every time I booted. (Prior to a month ago I was running cat 10.5.)

Even worse is some games start up and reapply the default (nonzero) underscan and I have to minimize the game, go into CCC and reset the underscan. It's very very annoying doing this every time I start Crysis (the only game that does it reliably). Oddly I noticed I have to leave the CCC window open or Crysis will reapply the nonzero underscan when I maximize the Crysis window... I want to point out that none of my nvidia cards have this problem!

So after being annoyed for this long and being unable to find a solution on the tubes I've been working on coming up with one myself and I think I'm close. I was poking around in the registry for my card and I found this registry entry:

[HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Class\{4D36E968-E325-11CE-BFC1-08002BE10318}\0000\DAL2_DATA__2_0\DisplayPath_3\MODE_1920_1080_60p_CEA861\Adjustment]
"Underscan"=hex:01,00,00,00,00,00,00,00

1920x1080 at 60 Hz progressive scan is the resolution I use and, astonishingly, the underscan value is not zero!! (Also the GUID is correct.)

Does anyone know if setting this to zero will fix my problem? Is it dangerous to try? Is there another way to fix my problem?

If anyone is unfamiliar with the sickeningly useless feature called "underscan" take a look at what it does:



----------- Unrelated Question ↓
I found this curious looking key set to zero and I was unable to find info on it. Anyone know what 'HighResBootCompatible" does?

[HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Class\{4D36E968-E325-11CE-BFC1-08002BE10318}\0000]
"HighResBootCompatible"=dword:00000000

[Delta6326]

i don't know if that will fix it but i have been getting annoyed by this. you can fix the underscan in the Cat.

[qubit]

@SF2: Yup, I've seen this too with AMD and it is indeed incredibly annoying and pointless. In my case, it was on a laptop with ATI graphics.

Thing is, it seems to happen only when I connect the card/laptop to a TV with a HDMI input. My monitor (1920x1200 resolution) with DVI input worked fine. I have yet to try it on the monitor's HDMI input.

I'll see if I can get round this tomorrow and get back to you.

You should be ok editing that registry value. You obviously know what you're doing, so there's no need to panic over it. Microsoft likes giving out overly dire warnings about editing the registry in order to cover itself, which then gets parroted everywhere else and scares the crap out of everybody. Heck, I've taken a hatchet job to it a couple of times when I had to remove the remnants of some errant driver (hundreds of entries) and it was ok.

You can always back up that registry branch first if your want to be extra safe.

[Steevo]

Its not dangerous. It is simply trying to make sure you use all of your monitor to the full.

Many monitors overscan by 5% so where they have uneven edges or some edges of video might be seen they won't show. So ATI decided it owuld be better to force users to adjust it to the proper width of the individual screen.

My monitor does it automatically. My 46" TV does not, but it does overscan by 3% natively, so I have to force 3% underscan to get my full picture without losing the edges, and half of the WMC controls showing.


Better for TV's, projectors, meh for most monitors.