Originally Posted by Peter Nixeus
Are you using the newest AMD Drivers?
There is something weird going on with FreeSync in the recent AMD Drivers - there are some current issues that has to be fixed. I just ran the AMD Windmill Demo with FreeSync ON and saw inverse ghosting on the Low Over Drive settings when I didn't see it in the past. I'm also seeing the FPS/Hz going jumping to over 60FPS/60Hz even though the AMD Windmill Demo doesn't support more than 60FPS during the demo test = causing brightness flickering.
I can't say anything about the AMD windmill demo - not used it. I've been using G-sync pendulum, TestUFO, some Unigine demos and a few different games.
I've tried 17.2.1 and the new 17.7.2 'Adrenalin' on Windows 10 x64, as well as an old 16.12.2 version on Windows 7 x64. Two installations and three different drivers, and the Freesync 'OFF' and 'ON' behaviour is the same with all of them. I've also tested the monitor on a laptop with Intel graphics and HDMI-out (limit 60Hz@1440p) to test and confirm how 'Over Drive' settings affect picture quality in fixed refresh, which ends up behaving just as the monitor does with fixed refresh on my AMD desktop.
Forgive any ignorance on my part, but how does the AMD driver play any role in how the monitor implements overdrive? I'd have though the gpu neither knows nor cares about overdrive?! The monitor accepts the input and decides for itself how to handle overdrive and response time compensation based on it's own h/w and characteristics, right? I don't understand why the gpu would factor in to the operation of a monitor-side feature like overdrive.
Originally Posted by Peter Nixeus
For the NX-EDG27 the recommended Over Drive setting is Low, where as Med and High may be too strong and may cause inverse ghosting (with FreeSync OFF) depending on the game or application you are running.
In case I didn't explain it well enough earlier; the 'Medium' and 'High' overdrive settings don't seem to differ from 'Off', so they truly don't seem to do anything when Freesync is 'OFF' (ie. fixed refresh) for me. That being the case obviously means inverse ghosting isn't a possibility on 'Medium' and 'High' if little to no response time compensation is even being applied.
The only overdrive setting the appears to do something
is 'Low'. However, that's only slightly useful and even then only when used with a high refresh. If 'Low' is used with a low refresh, I get extremely bad inverse ghosting in multiple different scenarios. (More details below)
This is the overdrive behaviour I see with Freesync 'OFF', on all of the system configurations I mentioned at the top of this post.
This is also
the behaviour I see with Freesync 'ON'. Given similar refresh rates, and given the same monitor overdrive setting, Freesync 'ON' will result in the same image quality as Freesync 'OFF'.
At 144Hz, it's often 3 frames of ghosting, seldom 2. 'Off', 'Medium', 'High' do nothing. 'Low' slightly helps the transition, but rarely does it reduce the total number of ghosted frames.
At 40Hz & 60Hz, I see 1 frame of ghosting. 'Off', 'Medium', 'High' do nothing. 'Low' causes terrible inverse ghosting of the 1 old frame, and at 40Hz it's a slap in the face.
3 frames is ~20ms of response time. That occurs with so many different rising and falling colour transitions!
This is what happens with Freesync 'OFF' (AMD or Intel) at those fixed refresh rates, and this is also what happens with Freesync 'ON' with manual frame-limiting to achieve the same equivalent refresh rate.
Freesync 'OFF' behaviour was tested with TestUFO browser tests, G-Sync Pendulum, Unigine Heaven, a few random games. Freesync 'ON' tested the same way, except without TestUFO. I've taken numerous photos at fast shutter speeds to be confident in what I've seen and measured, and that's ignoring how obvious it is to my own eyes in some scenarios as well (the reason I picked up on this in the first place).
All in all, I do not see any evidence of adaptive overdrive, nor do I see any evidence that Freesync 'OFF'/fixed refresh overdrive settings behave in the manner you described?! I cannot find a single way to positively implement overdrive suitable for lower refresh rates, nor can I find any way of getting even ~1 frames of ghosting, never mind the 0 frames of ghosting you'd want with overdrive implementation (even if there were inverse ghosting, this is a long way getting near to any form of overshoot). That being the case, the response time always seems higher than the 7ms required for ideal 144Hz input.
What am I to do?
P.s. I'd be curious to see how those different refresh rates and overdrive settings compare for others. Perhaps, the TestUFO 'Chase Squares'
page. Shouldn't take a minute and the inverse ghosting should slap you in the face at 60Hz and under. That is, unless of course other people have overdrive settings behaving differently to me?! Otherwise, I'll do an image dump if needed/necessary.