Using Winuae and G-Sync

[Shadowfire]

I built up a new emulation rig with the Checkmate1500plus case, explicitly for Amiga emulation.

I've got a build running that is FANTASTIC using Pimiga 4/400. My test case was Turrican 2 - it must scroll without any tearing and minimal input/audio lag on *both* PAL and NTSC emulation.

First, here's the rundown on the final configuration. The setup is black.

Case:
1x Checkmate A1500 plus case
1x beQuiet! 500W SFX power supply (case does not accept ATX form factor power supplies)
1x Enermax UC-12EB 120mm fan

Input:
1x Logitech MK320 wireless keyboard/mouse
1x Xbox One wired gamepad
1x Walmart ONN 3-port hub/SDcard reader Item#100014097 (This is the only walmart SD card reader I'd recommend, it can actually saturate USB2.0 transfer rates instead of operating at <5MB/sec like everything else I've gotten there, so I know it has a proper design)

Video (this is the key component - get a high refresh rate G-sync display and a G-sync compatible video card)
1x Viewsonic G-sync monitor model # XG2560 (240hz max rate) (includes Displayport cable)
1x Gigabyte Geforce GTX 1050Ti low profile video card, model # GV-N105TOC-4GL

PC components:
1x SAMSUNG 970 EVO PLUS M.2 2280 250GB PCIe Gen 3.0 x4, NVMe 1.3 V-NAND 3-bit MLC Internal Solid State Drive (SSD) MZ-V7S250B/AM
1x Intel Core i3-10100 Comet Lake Quad-Core 3.6 GHz LGA 1200 65W BX8070110100 Desktop Processor Intel UHD Graphics 630
1x MSI PRO H410M-A PRO LGA 1200 Intel H410 SATA 6Gb/s Micro ATX Intel Motherboard
1x Patriot Viper 4 Blackout Series 8GB (2 x 4GB) 288-Pin DDR4 SDRAM DDR4 3000 (PC4 24000) AMD Compatible Desktop Memory Model PVB48G300C6K
1x Windows 10 Home - 64-bit - OEM

I initially tried using the onboard Intel UHD-630 graphics with a 50/60hz 720p compatible HDMI TV, but it turns out that the Intel graphics driver is busted and disconnects the audio if you change refresh rates, and Intel customer service has no desire to fix their problems.
Also, the TV reports 1080p as an available mode (it will accept a 1080p signal and downscale it to 720p to display it) and the Intel driver insists on outputting only a 1080p signal, even though it is well aware that 720p is the native resolution of the display (1366x720p is reported as the recommended resolution on Windows desktop mode selection control panel). The result is a messy display that leaves you questioning if you need new glasses as the Intel gpu upscales everything to 1080p then the TV downscales it to 720p. Even "custom" display modes get upscaled to 1080p, its so bad its almost funny.

I then purchased a used Geforce GT 740 low profile video card. The idea was to use the new "low lag" video modes (where parts of the display are scanned out). The new card resolved the blurry-as-hell display, and the loss of sound when switching display modes issues, as the Geforce drivers default to the display's native resolution instead of the highest reported resolution.

While I could get it to work and not tear the screen at Lagless/2, using this mode produced audio issues (occasional pops) that I was unable to work around.

Thinking that the video card wasn't quite up to snuff for this, I ordered a 1050Ti. (Also, the GT 740 is not supported for G sync, but the GT750 is.) This allowed me to use Lagless/3 and Lagless/4 as well, but the audio issues remained.

I then ordered a 240hz G-sync monitor. All I can say is WOW! Once the settings are dialed in, this display is gorgeous. Attached are my WinUAE configurations. Note that I converted the Pimiga filesystem to a winuae .hdf fixed size image file (certain characters in the file names of some of the Pimiga files were causing issues for Windows explorer where I had to rename them using the 8.3 shortcut filenames, so this sidesteps that and as a bonus doesn't fragment the PC file system with 200,000 files).

Basically, you want to turn on G-sync in the control panel (important).
In Hardware/RTG board, set the WinUAE RTG board 24 bit color format to R8G8B8A8 (the default colorspace setting causes Pimiga to die when switching to RTG).
In Host/Display, set fullscreen mode to 1920x1080, default refresh rate.
Set native and RTG display modes to both to "Fullscreen"/"-"(No Vsync)
Set the refresh dropdown to PAL (or NTSC depending on your system, but it must match the "NTSC" checkbox in the Hardware/Chipset settings).
Tick the "FPS adjustment" box.
Follow Toni's advice, and DO NOT tick the "VRR monitor" box. This feature isn't yet ready for prime time and results in shattered audio IIRC. The good news is that WinUAE correctly deduced that I had a VRR monitor and the option box showed up on this system.
In the Host/Sound, drop the sound buffer setting ALL the way down to "Min".

This results in the display being fed a 240hz signal, no tearing, and no perceivable lag, at least on my end. It seems like the lagless / vsync modes result in occasionaly slight audio imperfections (that you can hear if you are paying attention). Setting the "FPS adjustment" box and "no vsync" seems to allow WinUAE to synchronize the audio perfectly, with -zero- tearing in either PAL or NTSC modes. The monitor's resolution is high enough that scrolling doesn't show any obvious artifacting due to the display resolution mismatch, too.

[Shadowfire]

Some notes:

1. On my primary system which is hugely more powerful (I9-10850K, Geforce 1080Ti) I am using a 4K TV which does not support 50hz, only 60/30/24. On this setup, when running a PAL configuration with Vsync (@1080p), there is no tearing (only the expected microstuttering, and ghosting due to pixel response times), but I need to run with the sound buffer set to 9 instead of minimum to not hear any pops in the audio. This is actually a pretty huge amount of audio latency, especially compared to the G-sync configuration, where I can't perceive any audio latency whatsoever. NTSC somehow makes it worse, requiring me to set the sound buffer to 10, which is more than 1/2 a second of lag; additionally, the display occasionally stutters, something which isn't happening on the Gsync setup.

2. It's really hard to convey the difference the Gsync setup makes without witnessing it in person. The sound latency and video quality is like the original hardware was hooked up to the original CRT display, but its on an LCD instead. I mean, I thought my primary setup was "ok", but the new one has me seriously considering upgrading the 4K TV to a Gsync display on my primary setup - just for what it will do for my PC games. The 60fps scrolling on Turrican 2 looks better, just because of the improved LCD response time; pixels aren't ghosting/smearing nearly as much as they do on the TV when scrolling. I guess I had just accepted this as the way it had to be on an LCD.

[dreadnought]

You don't get a "240Hz signal", that's just the maximum your monitor is capable of. I suppose any adaptive sync monitor (even the 75Hz ones) can do the job.

[Shadowfire]

Well... the OS is reporting a 240hz refresh rate, and the monitor is reporting a 240hz refresh rate, but if you want to believe that they're both lying to me, that's all on you. I don't have displayport decoding hardware to verify.
I can actually set it to 100hz with black frame insertion and ... it flickers almost like a PAL CRT display flickers... (yeah, it isn't actually interlacing the signal, but the headache inducing flicker really is there).

[Shadowfire]

Originally Posted by dreadnought

I suppose any adaptive sync monitor (even the 75Hz ones) can do the job.

If anyone has a setup with one of these, please respond in this thread. The freesync monitors are cheaper than the gsync displays.

[dreadnought]

Originally Posted by Shadowfire

Well... the OS is reporting a 240hz refresh rate, and the monitor is reporting a 240hz refresh rate, but if you want to believe that they're both lying to me, that's all on you.

We're talking about WinUAE, not your OS. A fullscreen WinUAE PAL setup should report 50Hz because that's what the monitor syncs to.

I don't know, maybe it's somehow possible you don't get stutter when monitor is displaying 240Hz and you are running 60hz NTSC games, because 60x4=240, but it's still odd, unless maybe it's not fullscreen.

Anyway, my point was that you shouldn't need 240Hz to achieve smooth scrolling in PAL. Here's how it looks on my 144Hz G-Sync monitor.



It works perfectly, with no visual or audio artifacts of any kind, hence I don't see why it should be any different on monitors with even lower Hz count.

[Toni Wilen]

It is monitor's max supported (and max allowed variable refresh rate) rate that Windows/GPU control panel reports, not current G-Sync/FreeSync rate which can change continuously.

Monitor should have some OSD page that shows current refresh rate. Or some 3rd party utility.

It also could be 100Hz instead of 50Hz by showing same frame twice, at least my G-Sync compatible monitor shows 100Hz when UAE is in 50Hz PAL mode.

[Shadowfire]

Monitor OSD reports "240 hz max refresh rate, Mode: G-sync"
I'd also assume that a 144hz display would be pretty smooth.
I'd like to see if the cheaper Freesync monitors can also replicate this experience.
It's just that I'll probably never buy an AMD video card to test it out (I'd buy a Freesync monitor, but not an ATI card).

[arcanist]

I use a RX 580 with WinUAE on a 144Hz Viewsonic XG2402.

I don't enable Freesync as there doesn't seem much point with WinUAE set to 50Hz display. Perhaps it'd avoid a mode change on alt-tab. The main reason to use a Freesync/G-Sync display is it's likely to advertise 50Hz modes.

With lagless vsync enabled scrolling is flawless and input latency is super low. I've also used a GTX 1070 with the same monitor and similar results.

[dreadnought]

@Shadowfire You don't need ATI card for Freesync monitor, most of them now work with Nvidia as well.

Old games only go up to 60Hz. The fluctuations happen under that limit and that's where the syncing takes place, so in theory any adaptive sync monitor which can handle stuff under 60Hz should work (at least this is my layman's understanding of it all).



This is from my 1080p AOC 144Hz Freesync monitor. It's the same flawless performance as on the one from my Acer 1440p I posted earlier. Note that the "100" in right top corner is this monitor's OSD take on refresh rate, and it fluctuates wildly (from 90-115). So it's similar to Toni's monitor.
In the left top corner is MSI Afterburner data and it correctly shows 50Hz. But it's stable 50, on my other monitor the OSD did show 49-50 fluctuations, which is the most exact of the lot.

About the point of using G/Freesync at all, instead of just enabling lagless V-sync (as @arcanist says) I don't know, but I seem to recall Toni mentioning there are some benefits too.

[Toni Wilen]

Possibly related, NVidia apparently finally added support for "Multiplane overlay" which removes DWM extra buffering. This should reduce latency in windowed mode. Basically windowed mode should now match exclusive fullscreen.

I am still not sure how to detect if MPO mode is in use and if current WinUAE windowed mode settings are optimal for this mode. (At least it requires Windows 8.1+ and Direct3D11 mode)

https://nvidia.custhelp.com/app/answ...tail/a_id/5159

EDIT: not sure if this affects g-sync or only non-variable refresh rate situations.

EDIT2: it seems to also need application support.

[dreadnought]

Originally Posted by dreadnought

Old games only go up to 60Hz. The fluctuations happen under that limit and that's where the syncing takes place, so in theory any adaptive sync monitor which can handle stuff under 60Hz should work (at least this is my layman's understanding of it all).

Seems I was wrong on this count and it works differently when it comes to emualtion. So, your adaptive sync monitor needs to be able to display multiples of 50Hz (and presumably 60Hz too), which excludes the low-Hz (60, 75) monitors, meaning you should get one with 144Hz minimum.

Still not sure why exactly it works like that, but that's what was stated in this thread: http://eab.abime.net/showthread.php?t=105802

[hexaae]

Originally Posted by Toni Wilen

Possibly related, NVidia apparently finally added support for "Multiplane overlay" which removes DWM extra buffering. This should reduce latency in windowed mode. Basically windowed mode should now match exclusive fullscreen.

I am still not sure how to detect if MPO mode is in use and if current WinUAE windowed mode settings are optimal for this mode. (At least it requires Windows 8.1+ and Direct3D11 mode)

https://nvidia.custhelp.com/app/answ...tail/a_id/5159

EDIT: not sure if this affects g-sync or only non-variable refresh rate situations.

EDIT2: it seems to also need application support.

Very interesting...

[Shadowfire]

Update:

I have purchased a Freesync monitor, a LG 24GN50W from my local Walmart for $160 (which is a whole lot cheaper than the current asking price of the Viewsonic XG2560 I originally used in the post.)

This is a 144hz Freesync monitor. For purposed of Amiga Emulation, it is the equivalent of the Viewsonic model but at 1/3 the price. I disconnected the XG2560, hooked up the 24GN50W, overrode and enabled G-sync compatible in the Nvidia control panel and did a reboot.

WinUAE came up and in fact @ 50hz it is visually and audibly identical to the more expensive viewsonic monitor. (It should be noted that the 24GN50W does NOT have integrated speakers, just a headphone jack, so you need to supply your own).

There is no reason to believe performance would be different with a supported AMD card on a Freesync monitor, so this one also gets a thumbs up. Perfectly smooth scrolling, no tearing, and no audio artifacts/popping.