Given how useful u/ryanrudolf 's refresh rate unlocker is on the LCD steam deck [allowing 30-70hz refresh rates on most LCD decks] and that I seem to have received an OLED steam deck before they did, I figured I would do a bit of display testing to see how far the OLED panel in my unit can be pushed. Here are my results:
Maximum timings (pclk method): 147.223 800 818 822 858 1280 1288 1290 1320 +HSync +VSync
Minimum timings (pclk method): 56.628 800 818 822 858 1280 1288 1290 1320 +HSync +VSync
Minimum timings (vblank from max pclk): 147.223 800 818 822 858 1280 1288 1290 5320 +HSync +VSync
Minimum timings (vblank from stock pclk): 102 800 818 822 858 1280 1288 1290 5320 +HSync +VSync
Maximum refresh rate (pclk): ~130hz
Minimum refresh rate (pclk): ~50hz
Minimum refresh rate (vblank from max pclk): ~32hz
Minimum refresh rate (vblank from stock pclk): ~22hz
VRR: Untested, but given vblank results, may be possible to force enable using an EDID override
Colours/gamma curves/brightness appear directly related to pixel clock / refresh rate, higher rates appear washed out, lower ones appear too dark.
Like with LCD models, flickering appears at low refresh rates
While I did not notice any negative side effects during or after my testing, operating electronics outside of their rated parameters may reduce lifespan or cause damage to said device, if anyone wants to test further, you do so at your own risk.
I may test if VRR works myself eventually if nobody else does so over these next coming days/weeks.
Great work looking into this! While higher refresh rates (if safe), notably up to 120hz would be appreciated, the biggest advantage would be related to implementing VRR, assuming it could be done safely and at a significant range of frequencies. I admit that full FreeSync VRR support was the one feature that I hoped would be officially supported on the Deck OLED to accompany its upgrade to 90hz and HDR capability. Given that VRR/FreeSync has more universally applicable benefits than either of the above, it seemed strange not to make a priority; don’t get me wrong I think the other upgrades are worthwhile and I’m glad they’re present, but VRR/FreeSync/VESA ActiveSync seems a notable absence.
If your work proves fruitful, perhaps it will encourage Valve to see if they could write something to officially enable an “experimental” VRR mode and/or 120hz refresh. In the last few years we’ve seen VRR come to mobile displays, even 120hz mobile displays and of course monitors/TVs have had such capability much longer. The LG OLED series since around 2020 have been 120hz and VRR capable with both FreeSync(Premium Pro/HDR) and Gsync (HDR) certifications, for instance. While I would have preferred an officially certified display for Deck OLED, if you can show that parity VRR functionality can be safely enabled, perhaps it will inspire Valve to look into it for a future update. Thanks again.
If it works, I expect the functional ranges, at least on my deck’s BOE panel, to be ~25-90hz, ~30-120hz, or ~35-130hz.
For now it looks like I will likely need to patch GPU drivers to enable VRR, because it still has not become available after using the older technique which typically works to enable it. That will unfortunately take a bit of time to do, maybe someone else can do so before I get time to do it.