LG 27GK750F-B - 240Hz, 27" 1ms Blur reduction, Freesync

[k2viper]

Finally I'm posting some pictures. Sorry for crosstalk pics, I tried to follow moving ufos with hand and chose "sport" mode which should use short shutter time.

First, is 240hz+MBR+VT1306 mode (pixelclock 639mhz). Kinda maximum VT i can get with smooth picture with no frameskips. Mode I currently stick at.



280hz overclocked mode. Shows out of sync message in Russlan (my display dont have English in OSD, just asian languages + Russlan + Ukralnlan). Frameskips, unfortunately



Same for 260hz. Frameskips.



241hz with reduced timings. Frameskips. Looks like reduced timings leads to frameskipping, and this was the cause of unsmoothness I mentioned in previous post.



Tried 180hz with VT ??? (forgot, used maximum to fill pixelclock). Works, but looks like strobing dont work outside 120/144/240-242hz, MBR feature greyed out.



Finally I tried "ultraclean 120hz" mode with max VT I could get working. Max working was between 1580 and 1600. But, I wasnt impressed by picture quality honestly. Crosstalk reduced compared to default 120hz, but 240hz with VT 1306 looks fairly better imho.

[Falkentyne]

Sort of similar to my findings when using certain Vertical Totals on Benq Mstar 8556T based monitors (XL2720Z, XL2420Z, XL2411Z, etc). Certain VT's at certain refresh rates will ALWAYS cause stutter from the panel.
1920x1080 @ 85hz, @ VT 1502, VT 1500, 1499, 1498 and 1497 will almost always stutter when switching resolutions to this or on a mode switch in the OSD. But VT 1501 works just fine...

Never heard about inverting porch values before though. That trick never worked on Benqs. Haven't tried it on any newer Benq. Still debating on whether to get a Realtek 2796BF based Benq monitor (XL2735) or that Dell S2716DG to try Gsync+ULMB at the same time on my laptop.

[lexlazootin]

If you get a 240hz you can do the G-Sync+ULMB trick up to 155hz instead of the 120hz max.

Be a ware that it's not a completely smooth experience, every frame dip sub millisecond long will adjust the brightness and flicker. Even in HL1 it's not completely stable.

[Falkentyne]

Would you say it's worth spending the $500 for the Dell TN monitor?

[lexlazootin]

Well you already have a 144hz monitor, unless you want the 1440p or the G-Sync/ULMB it might not be worth it. I think personally you have more to gain from a 240hz, you get higher ULMB+G-Sync and the added bonus of having a 240hz monitor. The only down-side is it's not 1440p and the price.

Only you can really decide if it's worth it.

[k2viper]

Sort of similar to my findings when using certain Vertical Totals on Benq Mstar 8556T based monitors (XL2720Z, XL2420Z, XL2411Z, etc). Certain VT's at certain refresh rates will ALWAYS cause stutter from the panel.
1920x1080 @ 85hz, @ VT 1502, VT 1500, 1499, 1498 and 1497 will almost always stutter when switching resolutions to this or on a mode switch in the OSD. But VT 1501 works just fine...

My finding is that stutter/unsmoothness I was getting at higher then 240hz refresh rates was due to frameskipping.

[Chief Blur Buster]

Frameskipping is not the exact same thing as simple stutters -- however, both can exist at the same time (e.g. stutters not caused by frameskipping, stutters caused by frameskipping)

To rule things out....
Could you take a few photos of http://www.testufo.com/frameskipping at Windows desktop

Do this with both G-SYNC enabled and disabled. (Windows won't vary the refresh rate, but the frameskipping mechanics of DWM may change) . Need to capture several with 40-square sequences to capture the 1-in-40. Camera exposure about 1/6 sec (use smartphone app), CPU set to 100% and all apps not running, to make sure browser is running flawlessly.

I don't think there is frameskipping in this G-SYNC monitor but I would love to definitively confirm.

EDIT: I noticed you edited your post and posted pictures. Thanks!

[k2viper]

This LG display do not support G-SYNC, its freesync but I dont have an AMD graphics card to test its VRR mode.

[k2viper]

LG provides a software tool called OnScreenControl for their monitors, and it can change all OSD features via software.

Doesnt this mean that LG is fully DDC/CI controllable?
How a user like me, can discover if there is hidden DDC/CI control options (regarding strobe timings, as its done for Benqs via Strobe utility)?
Sorry for the inconvinience.

[Chief Blur Buster]

From the pictures I am seeing, your monitor is indeed frameskipping. (at 280 Hz overclocked)