VG248QE G-Sync flicker

[Don]

I've noticed since getting my G-Sync kit that occasionally in some games, particularly during loading screens or from looking at particle effects like heavy smoke through certain angles my screen starts flickering. It looks like PWM to me, but I thought G-Sync was supposed to eliminate that. It's not too bothersome, and the list of games I've tested on is pretty limited, but some specific games where I've noticed it are:

Company of Heroes 2
- slight flicker on loading screen
- heavy flickering when viewing smoke from certain angles
- fairly heavy flickering on victory screen (a few animations & some particle effects)

Total War: Rome 2
- very slight flicker on loading screen
- heavy flickering in battles when turning 'Vegetation Alpha / Order Independent Transparency' on and looking at grass / foliage up close
- fairly heavy flickering during end turn AI processing

Drakensang The River of Time
- significant flickering during loading screens, otherwise I've not noticed it anywhere else

Just to note, my specs are:
i5-4670K @4.0GHz
PNY OC GTX 770 4GB
16 GB DDR3
250 GB Sandisk SSD
RAT MMO Mouse (pretty sure it's 1000hz poll rate)
Running 340.52 drivers

Any idea what could be causing this?

[Update] After some more investigation, it definitely seems to be happening in all low FPS situations. Not sure why FPS would dip so low even when the game is not rendering anything (i.e. loading screen), but whenever my FPS dips below 20 I get this very noticeable flashing / flickering.

[MrTommymxr]

some games have low frame rates in loading screens. Its not a problem, don't worry.
i notice the same in bf4.

[PoWn3d_0704]

Any time FPS is around 30, on stationary images (Like loading screens) I notice it. I know it happens in games, but you cant ever really tell.

[IwantGSYNC]

Wow, I didn't know that. I have high degree myopia so I try to find a screen that would be as safe for the eyes as possible. Flicker is definitely a big problem for me. What is the source of flickering?

[flood]

can u check the fps when the flickering occurs? (use fraps or some other fps overlay)

[Don]

From my testing the flickering is most noticeable when the FPS is below 25. Above that it's slightly noticeable up to about 30, after which things are pretty smooth.

[fenderjaguar]

The flickering comes because the refresh is so low. ie, if the frame rate is only 25, then so the screen is running at 25hz (if the refresh goes that low?).

I have noticed that 30hz does appear quite flickery, even though LCD hold and samples. If you look real close at the scree, it's more a tingling speckled phenomenon, rather than real flickering like a strobe

[Don]

Does it really make sense for G-Sync to match refresh rate to FPS when it goes down that low then? I don't think it's a very good experience.

[PoWn3d_0704]

Yes. If it suddenly shut off at 45fps you would have a pretty big visual shock I would think. 30FPS is good, and honestly, I have never really seen the flicker while actually in game just over a standing image.

For that reason, it really isnt a big deal.

[fenderjaguar]

Does it really make sense for G-Sync to match refresh rate to FPS when it goes down that low then? I don't think it's a very good experience.

I'm not sure how low the refresh goes to. Some say it doesn't drop below 30hz. I think it maybe goes to around 24hz, but I could be wrong