up vote 5 down vote favorite
2
share [g+] share [fb]

I have put together a new PC with a XFX GeForce GTX 260 graphics card and have it connected to my HDTV.

First, I used an old VGA cable with a DVI to VGA adapter and plugged it in to my HDTV's VGA port. Running at 1920x1080 it fit the screen perfectly.

Now, to avoid running another cable across the room, I have connected it with a DVI to HDMI cable to my TV's HDMI port, and the desktop at 1920x1080 is cropped by the edge of the screen.

I have "fixed" the cropping by using NVIDIA's "Adjust desktop size and position" tool, which created a screen resolution of 1814x1022 to fit the screen, but this is no longer the TV's native resolution and confuses some software (e.g. WoW).

Why does VGA work as expected, but HDMI is scaled up? Can it be avoided?

link|improve this question
67% accept rate
I have experienced this same issue using a GTX 275, DVI-HDMI Cable on my Samsung Series 4 LCD 1080p TV. – Nick Josevski Oct 15 '09 at 22:40
Same thing happens on my Samsung Series 6 with an ATI Radeon X1200. I have never heard of "overscan" before, but I'll definitely check it out. – Cory Larson Oct 16 '09 at 12:58
Ha, just did a bit o' research. The newer Samsung Series 7 HDTVs have an auto-compensation feature for overscan... great. – Cory Larson Oct 16 '09 at 13:06
feedback

4 Answers

up vote 6 down vote accepted

What you're seeing is called overscan. TVs have it as broadcasts in NTSC format sometimes did not fill the entire space on the screen. You'll need to look through your menus for a setting to adjust the overscan amount to 0%. You may even have to find a way to get into your TV's service menu to make this adjustment.

link|improve this answer
But why would that be different with an HDMI connection vs. VGA connection? – GraemeF Oct 16 '09 at 8:32
1  
This is just a guess. The manufacturers put the VGA port on the TV specifically for computers which won't need the overscan adjustments. So they're auto-disabled on that input. But they don't expect most consumers to be connecting their computers over DVI/HDMI quite yet, so the overscan defaults are left in place. – Ryan Oct 16 '09 at 18:15
@Ryan: That's correct. – jasonh Oct 19 '09 at 22:31
feedback
up vote 2 down vote

You don't mention what TV it is but you probably need to set the mode on the TV to 'Just Scan' or something similar under the picture menu.

link|improve this answer
feedback
up vote 1 down vote

I had the opposite issue with my Samsung and an ATI card, it was shown with black bars around the edge by default whilst running in native 1920x1080 - TV was set to 'just scan'.

I fixed this in the Catalyst Control Centre - there was an underscan option that by default was set to allow TV's such as yours to display the full picture - this scaled the image without changing the signal sent to the TV (i.e. it was still full HD and a standard resolution).

Not sure if nVidia has something similar though...

As for 'why different on VGA and HDMI' - I'm guessing this is the same reason as most standard displays - VGA is scaled based on the furthest active pixels in each direction (e.g. 'Auto adjusting' on most monitors) whereas HDMI contains resolution information which means no trial and error scaling. If the question was why different on DVI vs HDMI, I'd be stumped :)

link|improve this answer
feedback
up vote 0 down vote

I have an LED 24" view sonic monitor. I had the issue where the desktop at full res was outside my monitors viewable screen. On the input menu you can change from AV, to PC, to fix this. Could be similar on other types of Media.

link|improve this answer
feedback

Your Answer

 
or
required, but never shown
discard

Not the answer you're looking for? Browse other questions tagged or ask your own question.