Pixel doubling not working as expected

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evilsofa

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I am attempting to do pixel doubling with my NEC 20WMGX2 and a GTX 275 with the latest 196.34 beta drivers, but it's not working as expected for reasons I don't understand.

The 20WMGX2 is a 20.1" 1680x1050 display which is superb for gaming, but has a rather small dot pitch, which makes text smaller than usual. When playing older games with GUIs designed for 800x600 or 1024x768, text can get VERY small, with no good way in-game to increase the font size. Decreasing the resolution on LCD monitors creates a distinctive fuzzy look which looks bad due to data loss when pixels don't divide out evenly (imagine displaying a 14x14 image on an 8x8 display - you'll never be able to get it to look right). A solution for this is pixel doubling, where you set the game to run at exactly half the resolution of the monitor, making each game pixel display on four native pixels. So I am attempting to run at 840x525, which is exactly half of 1680x1050.

So I go to the Nvidia Control Panel -> Change Resolutions -> Add Resolutions -> Create Custom Resolutions panel. I set Horizontal pixels to 840, Vertical lines to 525, leave Refresh rate at 59, color depth at 32 and Scan type at Progressive. When I hit the Test button, it has that blurry non-native look, and the monitor's OSD reports that it's running at 840x524! What happened to the last vertical pixel?

When I click Timing and select Manual, I see more settings that I can change which hint at the problem and solution, but I don't understand them well enough to want to experiment. The settings are:

Horizontal:
Active pixels 840, Front porch (pixels) 24, Sync width (pixels) 80, Total pixels 1048, Polarity Negative (-), Refresh rate 32.82 Khz

Vertical:
Active pixels 525, Front porch (pixels) 3, Sync width (pixels) 6, Total pixels 547, Polarity Positive (+), Refresh rate 59.000, Pixel clock: 33.8221 Mhz

My hunch is that the odd numbers for the vertical front porch and total pixels are what is making me lose line 525. But I don't know what those numbers do or how I should change them, and I think it might be dangerous to experiment with them without knowing what I'm doing. Any ideas?
 
Try it with PowerStrip. I never knew about this before you posted it but I tried it with PowerStrip right now on my SM226BW and I get 840x525 without a problem. Looks a lot better than any other non-native resolution.
 
I must be really dense because I can't figure out how to use Powerstrip to do this.
 
Right-click the tray icon thingy, display profiles > configure > advanced timing options > custom resolutions > then type in the pixels under new resolution and click Add New Resolution. You'll probably have to restart and from then it should be available.
 
I got the 840x525 custom resolution to show up in the "User defined" section of Powerstrip's Custom resolutions page, but it's not available anywhere else. What now?
 
That's odd. It should be visible under Display Profiles. When I click that and select my LCD I can set it to 840x525. Oddly, the first time I added this resolution it automatically got changed to 848x525, so make sure that isn't the case. To fix that, I went to advanced timing options > custom resolutions > user defined, then I clicked the odd "848x525", set the aspect ratio to 16:10, manually typed in 840 x 525 again and set the vertical refresh rate to 60. Then I managed to apply it properly. Not sure why it decided to add those 8 horizontal pixels by itself, might be something similar to the way it shaved one vertical line off yours.
 
When I do that and click "Add new resolution", I get a quick blink of black and then a pop-up window saying "The display driver has accepted the new resolution. Do you want to try to switch to the new resolution at this time?" I say "OK", but nothing happens - it does not attempt to switch resolutions. So I hit all close and OK buttons, restart and still under Display Profiles all I get is "Display defaults" and "Configure...".
 
I finally found the 840x525 resolution somewhere. In Control Panel -> Display -> Adjust Resolution -> Advanced Settings -> List All Modes is listed "840 by 525, High Color (16 bit), 60 Hertz". 16 bit? When I try this resolution, I get a very flickery display which the OSD still reports as 840x524. I'm about to throw in the towel and uninstall Powerstrip.

Edit: so I went to the Nvidia Control Panel's Change resolution area, and in the Add Resolutions list when I enabled "Show 8-bit and 16-bit resolutions", I found the 840x525 16-bit custom resolution there, so I deleted it there. The 840x525 custom resolution was still in Powerstrip, so I deleted it and recreated it with no change. Experimented some more in the Nvidia Control panel, with no luck - any time I successfully create an 840x525 resolution, it actually displays 840x524.
 
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The only difference between your picture and the settings I'm using is that the "Composite sync" checkbox is greyed out.

I think I'll start a new thread with a better title to see if this is a monitor-specific problem.
 
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