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.
LTT said it’s because they don’t use a standard Displayport interface, but had to write a custom driver over SPI (think of a less fancy version of USB).
I don’t think it can do over 90hz because there isn’t enough bandwidth on the interface.
130hz comes out to a little under 150MHz pixel clock, interface bandwidth appears to max out about there because if I push things any higher it appears distorted or I get nothing at all.