Poor Display quality over HDMI

R

realmatrix

n00b
Joined
Jan 14, 2009
Messages
38
I connected my HTPC having sapphire HD 4670 over HDMI to my 37" panasonic lcd. I was expecting better quality than the vga connection.Even though it displays at the tv's native resolution ie (1360x768). the picture is unstable..text blurred . and poor contrast.The tv's manual does state that pc connection over HDMI is not recommended. but i have trouble playing some games over VGA ( the screen image shifts to the far left of the screen at times as I have manually adjusted using ati catalyst to the center). I read in the forum that pc display over hdmi is not an issue most of the times..hence I tried my luck

Is there any way to improve quality over HDMI or its just that the tv won't support.
 
have you tried setting the resolution to 1280x720?
 
Does the screen fit fully or is the image slightly too large to fit on the display?
ie have you got overscan on.

I had a 1080p LCD HDTV before my current one that could not be used via HDMI with a PC.
Bizarre but true. Analogue looked good though.
 
Some HDMI chips only work at 480, 720 or 1080 resolutions. Some GPUs can output these resolutions natively.
 
The image fits perfectly on screen no overscan only quality is poor. In fact even though image was crisp and clear in vga @ 1360x768 it swayed to the right of the screen i had to manually adjust it to the center.
 
I believe the correct resolution is actually 1366x768 not 1360x768. Those 6 columns of pixels make a huge difference if your tv is stretching it.
 
Yup, the panel's native resolution is 1366x768, and stretching/averaging pixels together causes shitty text quality. Some TVs you can get it to work decently on, and others just look like garbage no matter what graphics settings you try. That's why using a TV as a PC monitor or something where you need text, I always recommend getting a HDTV which can display a native resolution that is a multiple of 8. A HDTV which supports native 720p (1280x720) or 1080p (1920x1080) over the digital input is preferable. Through building dozens of HTPC's, I've found nvidia cards and video chipsets work best in HTPC applications. ATI is flaky as f*** and it varies drastically from model to model.
 
@realmatrix:
Is there a way you can check what resolution the tv is actually receiving? Normally pressing the Display button in the tv itself. Maybe is getting 768i and not 768p. I say this because I have one of the Westinghouse 37" with bugged EDID, and under Windows I get 1080i unless I do a registry edit to get 1080p. PS3 seems to detect 1080p fine tho. So yeah, that might cause text and moving images to look a little funky.

Also, where are you noticing this text abnormalities. Is it in your web browser, or in general? If it's the browser, then give Firefox a try. One of the reasons I use Firefox is because the text is more clear, compared to Internet Explorer or Safari.
If it's in general, then try to enable or disable ClearType, which handles how text is smoothed. If you're using XP, right click the desktop, and click "Properties". Now go to the "Appearance" tab, and click "Effects". From there, just try between Standard and ClearType, and see which one you like better.
 
True the native display resolution is 1366x768..but the display card will output only 1360x768 .I'll try to workaround with powerstrip and post the results.

Thanks
 
Before I try , is it safe to force 1366x768 through powerstrip to the display card knowing that it does not support it.
 
You might just crash the GPU by asking for a resolution it doesn't understand. PowerStrip is able to cause damage, but only to old CRTs that don't have any overscan protection. It could drive the electronics out of tolerance, but that's a thing that doesn't exist with digital. The worst thing that could happen is having to reboot.
 
OP, when you had it set to HDMI 1360x768 do you happen to have an "auto adjust" setting buried in your televisions internal control panel?

That feature has saved my butt on more than one occasion when tinkering with my 1366x768 TV (desktop HTPC).

Using Auto-Adjust and powerstrip you can experiment with 1360 and 1366 x 768 to see what gives you a sharp and stable picture. With 1360 you should have a thin black bar to make up for the missing 6 pixels, and no stretching.

Does your TV have another HDMI input? If so then you can experiment with the other input as well.
 
Sorry for the delay guys.. I was quite busy last month.
I was able to output 1366x768 through powerstrip but it hardly made any difference in picture and text quality.Instead it was trying to fight with the ati driver to take control of desktop resolution after every restart.I am currently back to 1360x768 through vga after tweaking with the tv's horizontal & vertical position keys I am able to cover all corners of the screen .No thin black bars are noticeable on the screen. FULL HD looks great even on VGA its just that I won't be able to play copy protected content if I purchase a blu ray drive later . But thats not a concern now.
Thanks for the help guys :) I will be posting pics in the gallery section once i get my camera back.
 
You must log in or register to reply here.
Back
Top