3840 x 2160 @30hz = mouse lag/typing lag/scrolling lag.

[onemoretimex]

Hey i asked this earlier and never got a reply so thought i'd see if anyone else online maybe knew about it.

I have my pc hooked up to my new 40' Philips 4k tv, at first it wasnt able to do my tv's native resolution... then i found out that AMD graphics card have some limit and needed a clock pixel patch to get it to recognize the max res.

Anyways patched it and changed it to 3840 x 2160 but can only get 30hz over hdmi.... and i'm noticing a lot of mouse/typing/scrolling lag..... i've even set my tv to pc mode and no joy.

and i have started to encounter this strange problem also



basically when im doing things on my desktop, opening closing tabs etc.... my screen will sometimes start to move position.... as you can see the start button is halfway across the screen and the other end of the desktop/notification area has moved to the left hand side.....

any ideas what might be the cause ?

 

[onemoretimex]

picture of whats going on with screen below


http://www.pchelpforum.com/attachment.php?attachmentid=60122&d=1453894795

 

[andy_Man]

What graphics card? I imagine it relates to the clock pixel patch, It's hard to have support when you are essentially hacking a graphics card to do something outside it's spec.

 

[ekagori]

Which AMD gpu are you using? The fact you had to use a pixel clock utility tells me your gpu is pre-GCN. Pre-GCN gpus do not support 4K resolutions, so any time you run hardware out of spec you run the risk of problems or even damaging your hardware. Plus, unless your gpu and TV have hdmi 2.0 ports, you cannot run 4K @ 60hz. You need either DP 1.2 or your TV to support MST so it can use two hdmi 1.4 ports to run @60hz.

 

[onemoretimex]

i have a crossfire setup AMD Radeon HD 8570D + HD 6670 Dual Graphics i have looked at the specs of both the apu and the standalone and both say they can output 3840 x 2160..... if using hdmi @ 30hz and display port @ 60hz.

my tv doesnt have a display port so i'm left using the display port to hdmi option. and running @ 30hz.

So my graphics cards are capable they just for some reason werent able to read the maximum resolution reported properly before the patch

 

[Wamphryi]

A 4K TV is not designed to deal with PC graphic requirements. What you needed was the Phillips 40 inch PC Monitor which comes with display port 1.2 capabilities. A GPU cannot drive 4K resolutions on HDMI.

 

[onemoretimex]

A 4K TV is not designed to deal with PC graphic requirements. What you needed was the Phillips 40 inch PC Monitor which comes with display port 1.2 capabilities. A GPU cannot drive 4K resolutions on HDMI.

i don't get what you mean if the graphics card say's it is capable of running 3840 x 2160 @30hz with hdmi then should it not be able to run smoothly ?

what about a hdmi 2.0 cable ?

 

[onemoretimex]

see im not to bothered about the resolution being that high when browsing the net or doing tasks etc..... it's just the difference it makes when im on netflix streaming a movie, or watching a film on vlc..... is there any way i can change the screen output res on vlc and netflix so that my desktop stays 1080p but the video is played at 4k

 

[ekagori]

Well, if you want to play content in 4k, it needs to be 4k, vlc or Netflix won't upscale 1080p.

 

[Wamphryi]

A 4K TV is not designed to deal with PC graphic requirements. What you needed was the Phillips 40 inch PC Monitor which comes with display port 1.2 capabilities. A GPU cannot drive 4K resolutions on HDMI.

i don't get what you mean if the graphics card say's it is capable of running 3840 x 2160 @30hz with hdmi then should it not be able to run smoothly ?

what about a hdmi 2.0 cable ?

HDMI 2.0 would probably help but just because the card manufacturers claim the card is capable does not mean it will do it well. Computers like 60 HZ and in my opinion cannot produce good results at 30 HZ. TV technology does not perform as well on a PC though movies would likely be OK but you can forget gaming. One 980 Ti barely manages and 980 Ti SLI is required for good gaming.