DVI, HDMI, 1080i, Gaming and nVidia SLI

nordicpc

Junior Member
Feb 1, 2006
11
0
0
OK,
I decided to try and work this issue out with nVidia before bringing it public, but the canned "We don't support our products" line has forced me out. Here's the deal:

I've been running HDTV on my Sony 21" CRT for over a year now over firewire from my cable box. I was not happy with a) the size of the output being all letterboxed and whatnot and b) the inability to see the cable box's menu on anything but DVI-D or Component. With the Super Bowl/March Maddness coming quick, I decided to buy my very first TV, which I decided would be a Sharp Aquos 32". It's got awesome blacks, good refresh, and very vivid colors.

Anyways, so here's the big deal. I ordered up a HDMI-DVI cable as the Aquos has only one HDMI input for digital signal. It was picked right up as "Sharp HDMI" on the 'puter, and the drivers decidedly want to run the display at 1080i. It's actually kinda hard to get 720p out of it, but that's ok. Needless to say, there's no way to force the TV to accept a native resolution from the input that I can figure, so it actually runs around 1100x700 with overscan compensation on, a far cry from the native 1366x768.

So the big problem is that when I'm trying to play pretty much any game from Quake 3 up to Quake 4, BF2 or FEAR, when SLI is enabled the machine locks right up once the display is initialized, or in the case of Quake 3 there's no OpenGL available. When SLI is off, the graphics driver forces the monitor into 1080i and then letterboxes the video.

What's worse is that when I first hooked this LCD up, it was getting a VGA signal in POST and the initial boot screens, and it actually looked pretty good. Now it's back to display adapter scaling, and 1080i is always on display, even with iTunes in full screen, where the VGA really looked much better.

Now, has anyone been foolish enough to think that a LCD would act more or less like a regular digital monitor and run into issues like this? Any help would be greatly appreciated.
 

YOyoYOhowsDAjello

Moderator<br>A/V & Home Theater<br>Elite member
Aug 6, 2001
31,204
45
91
You say it's hard to get 720p out of it?

I run 720p to one of my displays on a regular basis. Is it not an option for you?

Is 1280x720 the native res of the display?
 

kylebisme

Diamond Member
Mar 25, 2000
9,396
0
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Native res is 1366x768, and I don't think any modren Nvidia card can do that as the horizontal resolution isn't divisable by 8. Your video cards should do 1360x768 by default though, and 1368x768 as a custom resolution, but that will only work if your TV supports those signals on the input you are using and HDMI being a TV connection generally doesn't. If you have a VGA port on the TV that might offer more options, though it might not look quite as good either.

Oh yeah, 1280x720@60hz should work fine over HDMI, what is the problem you mention with that?
 

nordicpc

Junior Member
Feb 1, 2006
11
0
0
The problem seems to stem from how the drivers pick up the HDMI interface. Under HDTV Modes, there are none listed, however the resolution slider works fine and overscan compensation works like a charm. I have set the resolution slider to 1280x720 and used the overscan compensation to dial it in, and it works pretty well.

Text is quite unreadable, probably because of how the television does the resizing of the picture to it's native res. I don't have any options to run at native, which is disappointing. There is a serial cable connection, so I may be able to hack something together, but that's a project for another time.

The biggest issue I have now is that no games will run, period. I've gone into the configs and set 640x480 as the resolution, but to no avail. I have gotten Quake 4 to start once by disabling the scaling option and turning off SLI, but that's really not what I was hoping for. The drivers still force the output to 1080i and letterbox the output. Display adapter scaling locks the rig up, aswell as SLI.

I'm going to mess around so some more once I get a chance to. I'm quite busy, and today's my birthday so I'll be partying for the next 3 days or so and just enjoying the large screen for TV and DVD's. If anyone has had issues like this before, let me know. I'm hoping I can maybe set some registry keys for the drivers to force it to always display the overscan-compensated 720p, and I'd love to be able to use that second card as a single 6800 is just not enough juice to push at the res I want to. Thanks for all the help so far, and once I can get a few hours to document what all I've tried, all let you guys know.

BTW, great forums. There's a ton of info in here.