are you in the usa ??
PC timing
3840x2160 @ 60 Hz (HDMI1, 2, 3 only), 30Hz (HDMI4 only)
1920 x 1080@ 60 Hz
1360 x 768 @ 60 Hz 1280 x 1024 @ 60 Hz 1024 x 768 @ 60 Hz 800 x 600 @ 60 Hz
Response Time
8 ms (gray to gray)
50 '' for 309 bucks
I use there stuff and on there 1080p 32'' and well satisfied for all pc use ..
thing is get a wal mart + the extra walmart warrantee [I found that to be a big plus if there is any issue for return or exchange/ refund ]
http://www.sceptre.com/pub/Manuals/4KUHDTV/U515CV-UMS_UserManual.pdf
https://www.walmart.com/browse/electronics/led-tvs/sceptre/4k-ultra-hd-tvs/3944_1060825_1229815_1229821/YnJhbmQ6U2NlcHRyZXx8dGVsZXZpc2lvbl90eXBlOjRLIFVsdHJhIEhEIFRWcwieie?cat_id=3944_1060825_1229815_1229821&facet=brand%3ASceptre%7C%7Ctelevision_type%3A4K+Ultra+HD+TVs#searchProductResult
you see that 40'' for $250 ??? not speced as good and as a matter of fact the specs like I gave on the 50 '' above are not even listed in the manual at all [ don't think its a true 4k unit @ 60 ] and that's why
al ways got to go check these thing before you buy
anyway just a thought to ponder around 50'' pc timings at 4k@60hz 300bucks ?? makes that 27''' look like you looking at a postage stamp
anyway good luck on what you decide on and enjoy