r9 270x HDMI looks very blocky

Toggle sidebar Toggle sidebar
Q

quinncooper1988

Reputable
Sep 19, 2014
55
0
4,640
Hi,

Just rounding off my first build, and swapped the VGA cable for a new HDMI one.

Not changed any settings, and now when watching trailers of games or whatever, it's very very blocky and really bad image. VGA shows brilliantly.

Am I missing something here??
 
Solution
Solandri
Unfortunately, HDMI is mainly used by HDTVs. A TV HDMI signal is designed to be overscanned. That is, the image may be 1920x1080, but the TV enlarges it so it's slightly bigger than the screen, and crops the edges. There is no 1-to-1 pixel mapping and the TV's electronics smooths out the edges. On RL video images, this rescaling causes very little degradation.

On computer images this rescaling is devastating, and can cause blockiness and (for moving diagonal lines) shimmering. It may be that the first time you plugged in the HDMI cable, your monitor or TV thought it was a video signal and overscanned. The second time it thought it was a computer signal and didn't overscan. If you run into the problem again, search your...
Sort by date Sort by votes
Q

quinncooper1988

Reputable
Sep 19, 2014
55
0
4,640
just playing with the settings, and seems that changing from 1080p to 1080i does improve the pixilation somewhat, however now there is a really bad ripple effect on the screen. The video in 1080i is still not as good or clear as VGA.
 
Upvote 0 Downvote
Q

quinncooper1988

Reputable
Sep 19, 2014
55
0
4,640
ok so now I've gone back to VGA.... looks as this morning, great.

Un-plugged, and plugged HDMI back in....... and, well, perfect. Changed no settings or nothing.

No idea what or why, if anyone else has ever come across this before I'd be grateful to know what caused it as it's slightly bugging me!!
 
Upvote 0 Downvote
Solandri

Solandri

Illustrious
Jan 4, 2012
4,919
98
39,240
Unfortunately, HDMI is mainly used by HDTVs. A TV HDMI signal is designed to be overscanned. That is, the image may be 1920x1080, but the TV enlarges it so it's slightly bigger than the screen, and crops the edges. There is no 1-to-1 pixel mapping and the TV's electronics smooths out the edges. On RL video images, this rescaling causes very little degradation.

On computer images this rescaling is devastating, and can cause blockiness and (for moving diagonal lines) shimmering. It may be that the first time you plugged in the HDMI cable, your monitor or TV thought it was a video signal and overscanned. The second time it thought it was a computer signal and didn't overscan. If you run into the problem again, search your TV/monitor's settings for a "direct" or 1:1 or "computer" mode - that will turn off overscan.
 
Upvote 0 Downvote
Solution
Q

quinncooper1988

Reputable
Sep 19, 2014
55
0
4,640
I've had a search and couldn't find any setting as you described. I have an LG 22MP55HQ monitor. There was an over scan setting which was off both times.

When I first plugged the cable in I had big black bars around, so went into catalyst and set the over scan to 0%. Is still the same now.

All is working now, but if happens again will look further into those settings you mentioned.

Would getting a DVI cable be better than HDMI - I know both the same in terms of quality and digital signal. But I mean in terms of fit for purpose if a HDMI is more suited to TV's then would dvi be more suited to PC?

Again thanks for your response, it was very informative
 
Upvote 0 Downvote
You must log in or register to reply here.

TRENDING THREADS

Latest posts

Moderators online

Share this page

COMPANY
RESOURCES
FOLLOW
Top Bottom