7970 HDMI Not Reporting 120hz

bamato · Jan 24, 2015

Just bought a gorgeous new LG 4K tv for my HTPC. I've run into one problem though. Catalyst will only detect a maximum refresh rate of 70hz. It can detect the monitor is 4k, but can't detect it being 120hz enabled. Any suggestions?

Also, if I set the desktop resolution to anything higher than 1080P, it will only do up to 8 bit rather than the 10 bit it runs at at 1080p.

Lastly, 4k or even 2k gaming on a 7970 is turrible. I'll be sticking with 1080p until sometime down the road when GPU's are more 4k ready.

sweenytodd · Jan 25, 2015

A 120hz tv takes the 60hz (60fps) signal and adds in extra frames (fakes them in).

A 120hz monitor can take a 120hz (120fps) signal via dual-link dvi (2 cables)

Both panels can display 120hz but one is limited by a 60hz input.

Bishoff · Jan 26, 2015

sweenytodd said:
A 120hz tv takes the 60hz (60fps) signal and adds in extra frames (fakes them in).

A 120hz monitor can take a 120hz (120fps) signal via dual-link dvi (2 cables)

Both panels can display 120hz but one is limited by a 60hz input.

This. I'm surprised you're seeing 70Hz as well...are you using a DP cable?

EarthDog · Jan 26, 2015

Does the HDMI port on the 7970 support 120hz @ that res in the first place? I thought that came out with their r9 290/290x cards? And with Nvidia, the 9 series just released?

Bishoff · Jan 26, 2015

EarthDog said:
Does the HDMI port on the 7970 support 120hz @ that res in the first place? I thought that came out with their r9 290/290x cards? And with Nvidia, the 9 series just released?

On the 7970, HDMI shouldn't have output above 30Hz @ 4K (unless using 2 HDMI 1.4's) but on DP it can do 4K @ 60Hz I don't think DP can do >60Hz @ 4K

bamato · Jan 26, 2015

Interesting. Didn't know that HDMI was limited. The tv is capable of receiving 4k @60hz over HDMI, so I figured the card would send it. Sounds like I need to use DP for that though.

Also, if I change the resolution any higher than the 1920x1080, movie playback is stuttered a bit. And even the mouse movement and windows itself moves sort of slower and choppy. I knew I wouldn't be able to game at a higher res, but not even being able to do generic windows tasks seems strange, no?

Bishoff · Jan 26, 2015

bamato said:
Interesting. Didn't know that HDMI was limited. The tv is capable of receiving 4k @60hz over HDMI, so I figured the card would send it. Sounds like I need to use DP for that though.

Also, if I change the resolution any higher than the 1920x1080, movie playback is stuttered a bit. And even the mouse movement and windows itself moves sort of slower and choppy. I knew I wouldn't be able to game at a higher res, but not even being able to do generic windows tasks seems strange, no?

The stuttering & jerkyness of the mouse is more than likely due to the reduced refresh rate at the higher res (4k). It should be fine for movie playback as they're typically at a 24fps rate. In CCC, you can setup a more custom profile & select 24 or 30hz and this may help with the stuttering. Also try to play a movie using Media Player Classic. When I first built my server/HTPC rig, I had some odd stuttering/screen jitter @ 1080p with a 2gb 7870 using VLC. MPC fixed it and I never looked back.

If you still have problems or just hate the lower refresh rate, you can move up to an Nividia 970 which has HDMI 2.0 which supports 60Hz @ 4K.

http://mpc-hc.org/

bamato · Jan 26, 2015

I may have to go that route in the future (970). I use Power DVD 14 for all my media, as it's worked the best for DTS-MA and Dolby HD. It's also great for blu-rays.

I'll play with the refresh rate a bit when I get home. I use the Tv's webos to watch 4k media on Amazon and Netflix, but when 4K content starts to come in full force, I don't want to have any issues with the transition.

bamato · Jan 26, 2015

Messed with the refresh rates, still couldn't get the movies to smooth out.

The text in file windows and what not looks sort of blotchy and strange. Hard to explain. I took a photo to give a general idea. You can kind of see how the text looks sort of blocky. This is still apparent from 8 feet away. I just took a close pic to give a better visual.

Janus67 · Jan 26, 2015

I assume from not running at native resolution (1080p instead of 4k) so it is combining pixels/etc.

bamato · Jan 26, 2015

4k resolution on this TV from 8 feet away is pretty much hopeless for ever reading anything.... All the text in windows is so teeny.. Not to mention windows gets all laggy in 4k. Is the 7970 just not set up to run those resolutions?

I feel an excuse to upgrade to a 970/980 in the near future...

Janus67 · Jan 26, 2015

Try increasing the dpi to either 125% or 150%.

The 7970 shouldn't be having issues powering the desktop I just sold my boss a 7950 for his new 4k monitor and he said it works perfectly.

Maybe try a full driver wipe and reinstall of the omega drivers?

bamato · Jan 27, 2015

I'll give that shot when I get home tonight.

The TV displays 4K content without problem from Netflix, so I can't imagine the TV having problems. But who knows, could be a bad input.

Bishoff · Jan 27, 2015

bamato said:
I'll give that shot when I get home tonight.

The TV displays 4K content without problem from Netflix, so I can't imagine the TV having problems. But who knows, could be a bad input.

The increase in DPI will help with the user experience in 4K, especially using a browser. Try that other player I posted, for your videos that are stuttering.

If it still is buggy, try what Janus suggested with a clean driver uninstall and reinstall 14.12 (Omega) Use DDU to uninstall the driver as the regular add/remove programs in windows will not completely uninstall the AMD driver pack, which will cause problems.

bamato · Jan 28, 2015

Increasing the DPI worked pretty well for the text.

I didn't have a chance to do a driver wipe last night, and I'm hoping that will fix my issue. So I'll be trying it tonight.

bamato · Jan 28, 2015

Did a fresh driver install, no help.

I have determined that the problem lies in Power DVD 14. Just can't figure out why. I've uninstalled/installed it in hopes it would improve. but no.

I'm kind of irritated I can't use a piece of software I paid good money for to watch movies in higher res. But I can open VLC and have no issue. Just no DTS-MA in VLC.

Bishoff · Jan 30, 2015

bamato said:
Did a fresh driver install, no help.

I have determined that the problem lies in Power DVD 14. Just can't figure out why. I've uninstalled/installed it in hopes it would improve. but no.

I'm kind of irritated I can't use a piece of software I paid good money for to watch movies in higher res. But I can open VLC and have no issue. Just no DTS-MA in VLC.

I'm using a receiver that can decode DTS-MA ran directly from the HDMI graphics card to the receiver. There are ways to get the decoding to work that I haven't tried myself as receiver's are so cheap these days, it's almost worth not trying that route and just buy one. If you search for decoders & media player classic, you'll stumble across some forums that will walk you through the process. Also, you can probably use the same methods for VLC if you prefer that media player. I used to always use VLC but since trying out MPC, I never went back to it.

bamato · Jan 30, 2015

I have a receiver that plays DTS MA and Dolby True HD, but you still have to have codecs/software that will send that signal to the receiver. Otherwise it will try to downmix it to AC3 or pro-logic.

Bishoff · Jan 30, 2015

bamato said:
I have a receiver that plays DTS MA and Dolby True HD, but you still have to have codecs/software that will send that signal to the receiver. Otherwise it will try to downmix it to AC3 or pro-logic.

AMD cards simply pass the raw audio through...you don't need a sound card or software to decode the signal, as the receiver will do this. Check your supported formats tab in windows sound panel to confirm/ All of the codecs that your receiver can decode will be shown.

bamato · Feb 1, 2015

Strange. You'd think that the DTS MA tracks in MPC or VLC would just play then, but they don't. Power DVD is the only player I've found that allows the uncompressed audio to pass through.

On another note, just tried 3D gaming, and my god there is an unbearable amount of input lag.

7970 HDMI Not Reporting 120hz

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