4k input lag

[DEAMONFROST]

Hi a friend of mine bought a 4k tv that he hooked up to his pc.

But he gets this weird input lag on it.

The thing that makes it weird to me is that it is not present when he runs 1080p and the content in 4k like games or movies doesnt lag it is just the input of his mouse and keyboard that has lag.

We tried with another mouse and keyboard so it is not that and he has a 7970 with the latest drivers so the gpu should be able to run 4k.

How do i help him?

[Flojer0]

It probably only does 30fps in 4k mode due to an HDMI limitation. 1080p takes less bandwidth so it can jump to 60 fps and eliminate the lag. either that or there is some pre-processing going on in 4k mode that adds some input lag.

[lukeptba]

What cables does he use to transmit the signal from the gpu?

What are the specs of the tv?

[AMICLG]

It's probably that changhong or whatever one the Teksyndicate bought that are absolute garbage in every way and I'd tell him to sell it on ebay as there's no fixing the problem due to it being the hardware, sorry.

[Glenwing]

This is normal.  It's harder for the TV to do 4K.

[DEAMONFROST]

thanks for all the answers but it doesent have to do with the tv lagging since things displayed on it does not lagg and only input devises does like mouses and stuff.