Beamrace Lagless Stability

[buckrogers]

Tested a 1070ti on a 120Hz capable LCD. It supports 56Hz and up so I did no tests at 50Hz. Conclusions:

- No tearing at 100Hz or 120Hz, as per my experience with 100Hz CRT!
- Tearing seen at 60Hz at several slice settings.
- No tearing at 60Hz when number of slices set to 10 (or 3 or less)!

So where possible stick to 100+ Hz refresh rates and higher slice numbers for lag free and tear free gaming (assuming my experiences are typical). I guess there is a good reason for why higher refresh rates do not result in tearing but I will let more technically capable people to speak on this. The Blur busters chief and he who discovered beam racing alludes to it here: http://eab.abime.net/showpost.php?p=...&postcount=165

Where tearing occurs try as many different slice values as possible before slow down hits, and stick with 3 if none of the higher ones work. You will still reap the benefits of lower lag, albeit not as much as higher slices of course. I am guessing 3 slices begins to somewhat approach the lag of a vintage amiga, assuming the control device/interface is of a low lag variety.

Thanks to Toni for implementing this fantastic feature!

[Toni Wilen]

How does it look when debug bars are enabled? (END+F9 when in beamrace mode). Do they jump around all the time or only randomly?

Try also max power power management mode in NVidia control panel.

[buckrogers]

Ok that helped reduce the tearing. In general a high slice number shifts the tearing towards the top of the waterfall and a lower towards the bottom. Here is slice count 4:

[ Show youtube player ]

[buckrogers]

I have seen tearing on 100Hz crt too but did not see it yesterday and wondered why. Changed resolution to that which is native to the monitor (in this case from 800x600 to 1600x1200) and the tearing went away. I recall trying 1600x1200 @100Hz yesterday so the mystery is solved.

I will try 60Hz at native resolution on two different CRTs and report back.

[Toni Wilen]

Increase size (width) of the screen because there are also different bars that are hidden in your video. Those tiny blocks are not all

Always use native resolution because if display does the scaling (it should mostly work if GPU does the scaling): real and calculated scan line positions can't be in sync.

[Retroplay]

Sorry if this is wrong place but 4.3.0 bug thread is locked now.

Anyway, just a small update on the lagless beamraced fullscreen issue mentioned earlier.
http://eab.abime.net/showpost.php?p=...&postcount=128

I've noticed I have to load and start a windowed config before I start a fullscreen lagless beamraced config.
If I don't, it'll still crawl to a halt, but do it like above and it's working perfect.

Just a minor issue.

[buckrogers]

Issue resolved! I have been using single lines. From memory this was because when multiplying the size of the image (eg., x2.5, x3) the ratio would be all wrong or the workbench image would stretch to 16:9 or something along those lines.

Since using double lines, double fields, FS, and resolution autoswitch off, I now have no more tearing (and no weird stretching), even at 50Hz, providing the slice count is sufficiently high (in my case I think anything above 8 on my 15" crt but higher than 14 on my 20" crt).

[th4t1guy]

This might only be semi-related, but I noticed after installing the latest nvidia drivers (441.87) and enabling the new default max frame rate setting (58 fps) it would cause winUAE (4.3.0) to put out choppy audio as it wasn't doing the full 60 frames.
So just FYI in case anyone has that nvidia setting enabled to prevent tearing for other apps.