It doesn't and I know why now.
It's because of the scaler.
(Note: V4 firmware reported the scaler resolution in the factory menu, also known as the burn in menu. The OSD reported the physical horizontal and vertical resolution values directly)
The older Mstar scaler could be tricked into thinking it was running at a higher *RESOLUTION* vertically increasing the vertical total, but keeping the physical screen resolution the same. This forced the monitor to use 60hz backlight strobe pulse widths (persistence) values of 0.167ms to 5ms in 0.167ms increments, which is the reason the brightness got brighter, but the main thing that is far more important is that using a VT 1500 tweak on our older 1080p monitors made the scaler think it was working with a 1440p screen size, even though the display area (which was used to actually calculate pixel position) was still the same (1920x1080). But because the scaler thought it was working at 1440p vertical, the strobe crosstalk got moved DOWNWARDS relative to the amount of the vertical increase. I guessed this when version 4 firmware first came out and the FACTORY menu reported 1280x1440 at ANY refresh rate at native resolution, when a VT 1500 was being used. When a vertical total 1350 tweak was being used, wait I'll check real fast:
Ok just did VT 1350. The scaler reports the vertical resolution as 1280 (it actually says 1600x1280 which is a bizarre resolution, but the scaler reports weird stuff when the vertical total does not match the expected value. For example: At 1920x1080@120hz, the default VT is 1144. Using a VT of 1125 reduces both the horizontal and vertical values to the scaler causing it to report a VERY bizarre resolution: 1440x1050@120. (The OSD itself reports 1920x1080@120). I'm not sure why the horizontal decreases so drastically with such a tiny decrease in VT (19), but it's the vertical that matters when dealing with blur reduction, as the scaler uses this to set where the crosstalk is.
So using a VT tweak of 1500 sets the scaler to strobe an area of 1440 vertically instead of 1080, thus moving the crosstalk down the actual physical screen. This is why our legendary vertical total tweaks work!
oddly enough, at 100hz, default VT is 1133. using a VT of 1125 instead of 1133 stops the videocard from downclocking the memory at idle, but the scaler still reports 1920@1080@100. However sometimes it switches to the 60hz backlight pulse widths (this will limit the maximum Strobe Phase (Area) to 059 instead 100; 60+ shuts off the backlight.
Another side effect of this scaler stuff with the MSTAR Scaler is being able to downsample resolutions that are higher than native:
Example using the VT tweak we all know of and entering a custom resolution allows us to do this:
http://forums.blurbusters.com/viewtopic.php?f=2&t=2423
2560x1440.
The monitor OSD reports 2560x1440(@60hz even though its 100hz)
Guess what the scaler reports?
1280x1440 !!!
You can see the VT is 1500. anything higher than 1502 goes out of range. And anything lower than 1496 is also out of range (some values show a display with an out of range popup that can be closed by re-selecting displayport, but the main OSD is not accessible).
And I think you guys can figure out, the crosstalk at this downsampled resolution (2560x1440 on a 1920x1080 physical panel) has the EXACT same crosstalk as 1920x1080@100 without a vertical total tweak, since now, the actual vertical that the scaler was working with (before, with a VT tweak) is now part of the entire screen (instead of partially off the screen).
Hope this makes sense.
Since the
XL2730Z changed scalers and moved to the Realtek scaler, the realtek scaler handles strobing differently. Besides the broken 60 and 100hz strobing, VT tweaks don't work on this monitor (it seems like the realtek scaler is scaling the physical screen size) making this NOT an ideal monitor for strobing compared to the XL2720Z V4 ! Because there is no way to deal with the crosstalk now, and you're limited to 120 and 144hz blur reduction

TBH I'm really not sure why there is this "junction" separation between the vertical total and vertical resolution; I guess we will never know...
I REALLY wanted this monitor. I was ready to buy it on day one from newegg but I didn't have enough money at that time. Now that I see and knew all these new things< I'll be avoiding this monitor. Yes it has fresync and a much nicer image quality, but higher strobe crosstalk (like the old ones without VT tweaks) and blur reduction only working at 120 and 144hz makes this no different than the Nvidia equivalent of ULMB+Gsync
