G-SYNC use and issues log

[Ed Oscuro]

Edit: Here's the general setup: Geforce GTX 960 and Asus PG279Q.

Sorry for yet another G-SYNC thread, but here we go, some more impressions.

General impression: Mixed. Mostly good, but pretty fiddly so far, with a couple standout issues in this particular configuration.

I'm using a new 2GB GTX 960, in today (it'll be $159 after a rebate, not too bad). Hooked that up, noted the reduction in fan noise, then had some hours of frustration and a trip to a store to rule out some problems - the monitor wasn't reliably detecting the DisplayPort image, though it had no problem with HDMI. There were also some unrelated hijinks with Windows 10 and safe mode (make sure you know your account password if you're logged into a Microsoft Account, it won't allow the PIN until you're in and switch it back!) for a driver uninstaller. I also have a single dead pixel (all three subpixels are dead), low on the screen, in the middle, and a bit of yellow discoloration in white at the left corners of the screen, and a little bit of DSE - none of the color problems are very apparent with content onscreen, even on mostly white browser pages. Black levels seemed really high when I first started using it, and a camera test showed that glow was indeed much higher than my old Planar px2611w - but in use blacks look pretty much black again, so that's proving not to be a big problem. Not bad for a $100 off deal, though I might just return it and pay the full price for a better one.

Scaling isn't a big deal, except for DPI. Text is getting to be a bit small, but I've yet to work with images to see what I think about the extra vertical space.
One thing that has unexpectedly cropped up is handling of the screen corners. With my HD5850/1200p VGA monitor combo, it was easy to get the cursor to the top edge of the screen. But here it seems the cursor always ends up sucked into the right edge of the monitor, and just pulling the mouse up doesn't find the corner, EVER. It stays offscreen until I pull it back to the left. On the other hand, pushing the mouse up to the screen edge and THEN right works reliably. I hope this will be fixed with an OS install, and it's also possible I ought to replace my mouse, too. Lol, Microsoft.

"Low blue light" is a garbage feature that just about makes life not worth living. It is similar to stripping blue out of an image, leading to an obnoxious green tint over everything. Even worse, having played around with it and gone back to previous settings, the visual shock is such that the last good settings now don't look bright enough anymore. Can't unsee the blue light filter There wasn't much difference between the first four levels, but the last level notably bumps the brightness down. I might possibly use this for long reading sessions, but right now it looks like headaches are going to come from DPI and brightness issues, not blue light as such.

Drawing circles with the cursor test shows that 120Hz vs 60Hz isn't actually that amazing a change for that - I can tell there's about twice as many cursor trails, and they stay onscreen similarly as at 60Hz. Compared with the old monitor, there is a good improvement, though, in that motion is cleaner.

A quick test with endless runner Jetpack Joyride showed some ugly stutter in the background when my screen was set to 59Hz, which changing my desktop to 120Hz sorted out.
Game performance is spotty so far. Counter-Strike: Condition Zero: Deleted Scenes' training facility is still tough to render on this monitor - the image still breaks up on moving the cursor around. Not sure I've got this one figured out.
I loaded up a recent Half-Life 2 savegame, running at 120 fps, and I note it stutters for a couple seconds on starting up, but then is smooth. When starting the game with the Ravenholm-based menu background, I noticed some annoying banding in the clouds when the screen was darkened - an effect that appears when you open the Options menu. This might be due to the screen using an undithered 8-bit panel - the flicker and rolling lines of my previous analog connection are nowhere in sight, which is very nice.
Resident Evil: Revelations 2's raid mode seems improved. There's still hitches, and a general feeling of notable lag, because Capcom did some bad things with the MT engine that tax the regular CPU, while the GPU is underutilized. (I'm using the d3d.dll "fix" that's been floating around for a while; I'll try playing the game without soon.) However, one particular thing which was guaranteed to cause a frame drop now isn't, so I'm happy about that. At the moment, I'm not worried about setting the game above 60Hz.
Duke 3D: Megaton Edition's got some performance issues - uneven FPS with some hitches. My settings here were to change it from the default 170 max fps, to 120, and then back again.

I haven't tried RetroArch yet (else I'd be posting in that thread) but I will note that a good new install of Windows 10 might fix some things.

[Fudoh]

You might want to mention which monitor you got (for those not following the other threads).

Also, Ed, we don't want to hear about your Counter Strike experiences, you want to hear how smooth Raiden Fighters and R-Type are running

[juji82]

You might want to mention which monitor you got (for those not following the other threads).

Also, Ed, we don't want to hear about your Counter Strike experiences, you want to hear how smooth Raiden Fighters and R-Type are running

^^ THIS! It is an appealing combination with mame (finally) ...

[bobrocks95]

Are 8-bit panels still the norm? Did you have a 10 or 12 bit panel before so the banding is noticeable to you now?

[Fudoh]

almost all IPS consumer displays these past years used 6-bit + dithering and it hardly bothered anyone, so real 8-bit is quite ok. 10-bit is for the high-end displays. And it needs support through the video card which isn't this easy to accomplish for an all-purpose machine.

[Ed Oscuro]

Right you are, guys! I think actually the Jetpack Joyride test shows pretty well that MAME is going to be fine (in that case, the background scrolling direction is horizontal, right to left <- ), but I'll take another look at that in particular. I am first going to update my setups for DOSbox, I've got a few old Apogee sidescrolling games that I was playing earlier on the old setup.

I already have a few things to update:
- On startup, Windows throws an error about "mom.implementation" which I saw earlier. I've never had Windows 10 make those jokes before; the Internet suggests that AMD's horrible drivers left me a gift. It's possible some of the problems I noticed will disappear with a clean OS install.

- Counter-Strike CZ has some weird things going on, it's still running 59/60fps ingame. Sorry Fudoh

- About 8-bit panels: Buried in my Half-Life 2 response is a comment about banding issues. More precisely, what I see is the shade of some particular gray clouds going through steps - not changing smoothly - when the menu gets pulled up, which is essentially fading those shades of gray. Note that Ravenholm's skies are pretty gray. Gray colors seems to bring out some of the worst in this panel, as expected - of any IPS display. On my previous display, I had a fairly old CFL backlight (set to a really low brightness) and a lot of faint but persistent flickering / visual anomalies which possibly masked any banding of this type, and it was probably 6-bit with dithering as Fudoh says, so the problems would have been more subtle. It's also possible that I just don't remember it, because I didn't look at that scene on my old setup recently - it might have been a problem on the old screen too. I think the pg279q comes with a real 8-bit panel. Overall, I don't think this is a huge case, but depending on what you use it for it could be annoying. And Fudoh's comments here are spot-on too; if I was more patient I would have simply waited for high-fps HDR displays with a high bit depth in the panel.

With this screen's backlight turned *way* down (I turned it down to about 12 brightness, less than half the TFT Central suggested setting) the general look of things is pretty good - mostly familiar, but with a few improvements. At this brightness level, white starts to look more like an eggshell color - slightly beige, with backlight bleed in places tinging it a bit brown. It's not as bad as it sounds, though; I mainly turn the backlight down because too much brightness hurts my eyes, which is a bigger issue.

Overall, I think that to get the "next step" in performance we'll need to move to a different technology, as I feared. This is definitely a good step in the right direction, but $700-$800 USD is a lot to pay for eliminating tearing.

[bobrocks95]

Color depth has always been a weird thing for me to grasp. My Sony W700B can be fed 12-bit and reports it as such, but I'm guessing is an 8-bit panel and downsamples the color so to speak.

Panasonic plasma marketing material claimed 14-bit processing around 2006 (and 10-bit in 2004- maybe true?), which would be 4 trillion colors and is obviously marketing fluff, but must come from somewhere.

[Ed Oscuro]

Further edit: The screen edge cursor business has sorted itself out.

Duke 3D Megaton is behaving well at 120fps now, except for one thing: Now the weapon bob animation is distracting with the scenery smoothly scrolling by

[Fudoh]

I am first going to update my setups for DOSbox, I've got a few old Apogee sidescrolling games that I was playing earlier on the old setup.

oh, that's interesting. I doubt that too many of the old games were actually running at 70fps, but I guess you can run the display at 70Hz now to at least get a CRT-like experience for MCGA/VGA games. I guess many people would be surprised to see what smoothing scrolling DOS was capable of while DOSBox was sacrifying most of that by running on a 60Hz Windows desktop instead.

[Thomago]

DOSBox was sacrifying most of that by running on a 60Hz Windows desktop instead

In case somebody is bothered by that (well... everybody should): It's a really good idea set up a custom 70 Hz resolution for DOSbox. I guess success isn't guaranteed as some PC monitors may not be able to output 70 Hz, but it's worth a try!



I'm using the Custom Resolution Utility for that as I'm also using Nvidia's DSR and that disables setting custom resolutions in the driver for some idiotic reason.

[ZellSF]

I've had bad luck with standard LCDs supporting 60hz.

G-Sync works perfectly with DOSBox thankfully.

[Thomago]

G-Sync works with DOSbox? Woah, cool info.

[Lord of Pirates]

Right you are, guys! I think actually the Jetpack Joyride test shows pretty well that MAME is going to be fine (in that case, the background scrolling direction is horizontal, right to left <- ), but I'll take another look at that in particular. I am first going to update my setups for DOSbox, I've got a few old Apogee sidescrolling games that I was playing earlier on the old setup.

I already have a few things to update:
- On startup, Windows throws an error about "mom.implementation" which I saw earlier. I've never had Windows 10 make those jokes before; the Internet suggests that AMD's horrible drivers left me a gift. It's possible some of the problems I noticed will disappear with a clean OS install.

- Counter-Strike CZ has some weird things going on, it's still running 59/60fps ingame. Sorry Fudoh

- About 8-bit panels: Buried in my Half-Life 2 response is a comment about banding issues. More precisely, what I see is the shade of some particular gray clouds going through steps - not changing smoothly - when the menu gets pulled up, which is essentially fading those shades of gray. Note that Ravenholm's skies are pretty gray. Gray colors seems to bring out some of the worst in this panel, as expected - of any IPS display. On my previous display, I had a fairly old CFL backlight (set to a really low brightness) and a lot of faint but persistent flickering / visual anomalies which possibly masked any banding of this type, and it was probably 6-bit with dithering as Fudoh says, so the problems would have been more subtle. It's also possible that I just don't remember it, because I didn't look at that scene on my old setup recently - it might have been a problem on the old screen too. I think the pg279q comes with a real 8-bit panel. Overall, I don't think this is a huge case, but depending on what you use it for it could be annoying. And Fudoh's comments here are spot-on too; if I was more patient I would have simply waited for high-fps HDR displays with a high bit depth in the panel.

With this screen's backlight turned *way* down (I turned it down to about 12 brightness, less than half the TFT Central suggested setting) the general look of things is pretty good - mostly familiar, but with a few improvements. At this brightness level, white starts to look more like an eggshell color - slightly beige, with backlight bleed in places tinging it a bit brown. It's not as bad as it sounds, though; I mainly turn the backlight down because too much brightness hurts my eyes, which is a bigger issue.

Overall, I think that to get the "next step" in performance we'll need to move to a different technology, as I feared. This is definitely a good step in the right direction, but $700-$800 USD is a lot to pay for eliminating tearing.

I've been running my XB270HU at 18 brightness for the same reason, having the brightness too high on any display gives me a serious headache. It had some bleed issues that sorted themselves out through use.

Color depth has always been a weird thing for me to grasp. My Sony W700B can be fed 12-bit and reports it as such, but I'm guessing is an 8-bit panel and downsamples the color so to speak.

Panasonic plasma marketing material claimed 14-bit processing around 2006 (and 10-bit in 2004- maybe true?), which would be 4 trillion colors and is obviously marketing fluff, but must come from somewhere.

Games have been 8bit color depth for a long time now, I don't know of anything that runs 10bit or higher.

[Guspaz]

the Internet suggests that AMD's horrible drivers left me a gift.

What AMD drivers would you be using, with G-Sync being nVidia-specific?

[Xyga]

Games have been 8bit color depth for a long time now, I don't know of anything that runs 10bit or higher.

+1
We don't need 10, 12, 14bit or whatever.

Maybe in the future there'll be enough HDR-compliant movie and game content requiring compatible 10bit panels in consumer form, but right now those dephts are indeed only useful to specific professional jobs.

[Thomago]

We don't need 10, 12, 14bit or whatever.

For games, 10 bit would actually be welcome, as it would get rid of the heavy color banding today's games display.

[Xyga]

I mean the games would have to be coded with the right colors, but most existing games aren't, buying a 10bit display doesn't magically make 10bit colors.
People frequently make that mistake when buying higher color depht displays.

[Ed Oscuro]

Overall things are going pretty well, but I'm noticing games seem to be often very dependent on low CPU loading to hit 120Hz. I don't think that should be happening with an i7 3930k, and it might be that a bunch of things have gotten misconfigured over time (Firefox using up too much CPU is a good example).

the Internet suggests that AMD's horrible drivers left me a gift.

What AMD drivers would you be using, with G-Sync being nVidia-specific?

"Left" is a clue here. AMD botched the rollout of their Crimson drivers and the uninstall didn't catch everything (which may or may not be related to Crimson).

@ Xyga: Actually, many games are rendered using HDR already, and more bit depth is necessary to allow it to do more than just present bloom effects and faked dynamic range.

[Xyga]

@ Xyga: Actually, many games are rendered using HDR already, and more bit depth is necessary to allow it to do more than just present bloom effects and faked dynamic range.

Those 'many' I bet are PC-only games I don't play (I'm 99% arcade-retro-consoles ^^) because I don't see how it would be possible otherwise, you need a compatible display and gpu I imagine ?
For me over 8bit and HDR are still only expensive gimmick, like 4K, 3D, curved screens etc.

[Guspaz]

I've got a GTX 970 and a U2711, both support 10-bit display output. It's the software side that is the limiting factor.

Games already tend to work with high bit depth internally, and then things get quantized to 8-bits per channel.

[Xyga]

Well I understand that may be nice but really it's only for PC gamers, personally I don't know if I will ever have a need for this.

For me G-Sync is the real progress, waiting for a full report from Ed with every emulator out there.

[Ed Oscuro]

Games already tend to work with high bit depth internally, and then things get quantized to 8-bits per channel.

This is the major thing.

Oh, and most games don't use 10-bit+ assets because it's wasteful of memory space.

But all the graphics cards have supported high bit depths for many years - probably since the early '00s. As usual, I guess we'll have to wait for consumer video to lead the way again - that'll lead to HDR TVs and more adoption of high bit depths.

[BONKERS]

almost all IPS consumer displays these past years used 6-bit + dithering and it hardly bothered anyone, so real 8-bit is quite ok. 10-bit is for the high-end displays. And it needs support through the video card which isn't this easy to accomplish for an all-purpose machine.

If the display enumerates it, modern GPUs will work with it fairly easily.



Also: When it comes to Half Life 2, or ANY modern Video Game, using them as a judge the panel's native depth and banding issues is NOT a good idea.

Simply because most games do not render natively in high precision for all buffers and effects. That'd be a performance issue.
Many times it's lower, or they come up with methods to interpolate or dithering of sorts.
The most common precision format in games is probably R8G8B8A8, but that might only be relevant to HDR or the Depth,etc. Lots of games have hodge podge set ups with a lot of mixed formats.

Here's a quote from the book GPU Pro 6 from a section about Contact Hardening Glossy Reflections

The algorithm for CHGR rendering is as follows. First, we output the distance
between the reflecting surface and the
point where the reflected ray hits the
reflected object. Because we want to limit the size of the render targets, weutilize R8G8B8A8 textures for color and depth information. As 8 bits does not
provide enough precision for distance, we pack the distance in two 8-bit channels
during the SSR pass, as shown in Listing 1.1.
The IBR pass unpacks the depth, performs blending, and then converts this
world-space distance into screen-space distance as shown in Listing 1.2. The
reason for this is twofold. First, the screen-space distance fits naturally into the
[0,1] domain. As we do not need much precision for the blurring itself, we can
re-pack it into a single 8-bit value, ensuring a natural blending. Second, the
screen-space distance provides a better c
ue for blur ratio: the fragments farther
away from the viewer should be blurred less than closer ones, if both have the
same reflection distance

Textures are also most likely compressed with DXT compression, which even at it's best has lots of issues, artifacts and quality problems. (Some that developers have created work arounds for etc. Some that don't bother and lazily use poor settings when they shouldn't.) I don't think i've seen any game ever use anything more than native 8-bit textures. And that's less often than not because it eats memory. (Remember that the majority is designed for consoles first and even though the PS4 has a decent amount of memory. Things like that are considered an optimization.)

If you want a TRUE test for 10-bit+ support you need to do things like
http://forum.doom9.org/showthread.php?t=172128


Also: HDR TV is not all that great
http://timothylottes.blogspot.com/2015/ ... ology.html

[Ed Oscuro]

Interesting info, thanks!

HL2 has a lot of suboptimal settings for the sake of "stability" on low-end (*really* low-end by today's standards - lower than the GPU I just replaced) anyhow, including various aspects of texturing. So perhaps no monitor will display that scene as intended. Still, worth noting as it represented a change from my previous display (or so I thought; I could be wrong there).

In any case, the point is more to point out how well or poorly common games play together with the monitor, not to test banding or bit depth in a vacuum, which would be meaningless.

[Ed Oscuro]

Not a lot to report on the Raiden DX & Fighters front - everything looks fine on both, scrolling is smooth, there's no visual anomalies jumping out at me.