AMD Developers Begin Making Open-Source FreeSync/AdaptiveSync Plans

[juno]

what makes you think nvidia cards have hardware for adaptive sync?

- It's not like there's any special hardware on the graphics card specifically for gsync. All that's needed is a display port 1.2 or later display interface.
- They have modern display port connectors, and while they don't claim to be 1.2a compatible, I'm sure they could with the right software. It's a very small step.
- All the complicated hardware which enables dynamic refresh rates is in the monitor, not the graphics card

Yes, it is an assumption on my part, but I don't think it's far fetched.

Adaptive Sync is an optional part of the DisplayPort 1.2a standard. Not every DP1.2a device supports variable refresh rates nor does every (or any) display panel support arbitrary refresh rates.
I said it before, Nvidia is using an additional G-Sync module inside the monitors but can do G-Sync without it in Notebooks via embedded DisplayPort. Thus, the G-Sync module is not really required. They could support VESA Adaptive Sync if they wanted.

[Brisse]

nor does every (or any) display panel support arbitrary refresh rates.

Freesync/Adaptive Sync monitors define their dynamic refresh rate range in the EDID. It's then up to the graphics driver to respect these limitations.

Funny thing is that the range can be modified in the EDID and as long as you put in reasonable numbers it might work. For example, my MG279Q officially supports Freesync between 35-90hz, but I prefer to run it at 44-120hz. 57-144hz will also work. LFC takes care of the lower limit and duplicate frames up to three times, so the actual range if running 44-120hz is 44/3 = 14.7 - 120fps.

[mibo]

Freesync/Adaptive Sync monitors define their dynamic refresh rate range in the EDID. It's then up to the graphics driver to respect these limitations.

Funny thing is that the range can be modified in the EDID and as long as you put in reasonable numbers it might work. For example, my MG279Q officially supports Freesync between 35-90hz, but I prefer to run it at 44-120hz. 57-144hz will also work. LFC takes care of the lower limit and duplicate frames up to three times, so the actual range if running 44-120hz is 44/3 = 14.7 - 120fps.

Do you modify this in Linux?
I read about an tool CRU for Windows but don't know if such thing exists for Linux.

[Brisse]

Do you modify this in Linux?
I read about an tool CRU for Windows but don't know if such thing exists for Linux.

No, I've done it on Windows using CRU. I hope something similar will be possible on GNU/Linux once Freesync gets properly implemented.

[gbil]

No, I've done it on Windows using CRU. I hope something similar will be possible on GNU/Linux once Freesync gets properly implemented.

You can create a custom EDID file, the issue is that AMDGPU driver doesn't support the custom edid option in xorg configuration.

[RealNC]

but IPS screens have their own problems (latency)

This has been solved now. Low latency IPS panels are now available. (They're more expensive though, at least as of 2017.)

[mibo]

Thank you Brisse and gbil.

[juno]

Freesync/Adaptive Sync monitors define their dynamic refresh rate range in the EDID. It's then up to the graphics driver to respect these limitations.

Funny thing is that the range can be modified in the EDID and as long as you put in reasonable numbers it might work. For example, my MG279Q officially supports Freesync between 35-90hz, but I prefer to run it at 44-120hz. 57-144hz will also work. LFC takes care of the lower limit and duplicate frames up to three times, so the actual range if running 44-120hz is 44/3 = 14.7 - 120fps.

Yep, I've always been running mine at 56-144

[Brisse]

Yep, I've always been running mine at 56-144

I kind of understand why they went with 35-90hz since this model came out before AMD introduced LFC in their driver, but now that LFC is a thing, it definitely runs better at 120 or 144hz. Also, BluRay's @ 23.976fps doesn't sync well at 90hz but will sync perfectly at 120/144hz.

[juno]

I kind of understand why they went with 35-90hz since this model came out before AMD introduced LFC in their driver, but now that LFC is a thing, it definitely runs better at 120 or 144hz. Also, BluRay's @ 23.976fps doesn't sync well at 90hz but will sync perfectly at 120/144hz.

Yeah, might be the reason. However, IIRC other screen manufacturers had an option in the OSD to switch between a lower (min to medium refresh rate) and a higher (medim to max) FreeSync range, which I thought was a nice feature. It's still fine, though, because I prefer playing in higher rates anyway and I'm able to adjust the EDID.

For BluRays FreeSync might also be interesting. Using Windows, mpv already works with FreeSync.

BTW: While I don't play under Linux, I use a custom EDID there too. Simple reason: default mode in the EDID is 60 Hz and many Wayland compositors don't allow switching modes yet, so I have an EDID with the 144 Hz mode.