Just checking in with a success report in case someone else wants to try this.
Edit: Improved version with advice from the Chief in the following post. The timings below work, but are suboptimal.
TL;DR:
>30% faster frame transport, yay.
See attachment for CRU screenshot. In text for future reference/search engine/etc:
Code: Select all
CRU parameters:
2560 1440
8 3
32 10
40 553
(80) 566
(2640) 2006
119.999
(240.719)
(635.50)
Story time:
Why:
Recently developed some eye/CNS problems and persistence is a major problem, so blur has gone from "annoying" to "blinding". My endless search for low latency has shifted focus (heh heh) to low blur. I'm gaming on a Viewsonic XG2703-GS which is a 1440p 165Hz Gsync monitor, and the 7ms response time with overdrive enabled (!) isn't helping.
This led me to try ULMB, again - I'd tried ULMB in the past but it just didn't compare to G sync - it wasn't the tearing, it was the appearance of the (normal, tiny) frametime variations, presenting themselves not unlike microstutter. Throwing S sync in the mix gave it the edge, not only removing the tearing but most importantly creating rock solid frametimes (since it's effectively a limiter synced to the vertical refresh clock which is plenty stable). That's removed the blocks and now I can really appreciate ULMB in all its glory. I have been missing out. HIGHLY recommended combination.
Of course, the massive improvement in picture quality is not free, scanline sync needs a beefy GPU to keep the frametimes consistent, but even still, there is a small input lag increase. While I'm reading up on this, I stumble over Mark discussing QFT. Fast forward a few weeks....
What:
Actually came here for help after I'd given up, tried one last thing before posting (it pays to search before you post even if you already searched!).... and I have a winner! I have 120Hz (including ULMB) working at a 165Hz pixel clock. That's 2006/1525=1.3154=over 30% faster, thanks!! It's entirely possible that even bigger VBI will work with this monitor, but honestly, I'm still slightly in shock at the fct that it's working and I'm not game to touch it. This is good enough for me for now, but if you do better, please share
How:
I'd attempted to get it working at 144Hz (and a bunch of other stuff, I'll spare the boring details) and had zero luck, but the thing that worked in the end was:
Enable the overclock mode on the monitor, copy the 165Hz overclock parameters in CRU, paste them into the 120Hz profile, set the refresh rate back to 120Hz, and crank up the back porch until the pixel clock is as close as possible to the clock for 165Hz.
Pretty basic methodology I know, but it works. At least, it worked doing this based on the 165Hz overclock profile....not on ANYTHING else I tried. The overclock mode does not need to be enabled on the monitor for these settings to work. I just used it to find the settings, you can leave it off if you want to.
If you have a G sync monitor I can only hope for your sake that you'll give this a shot, it's magic... And if you have this nice old Viewsonic monitor, now you have settings you can use without experiments