Identical Panels
-- Both the
PG258Q, the
XL2540 and the
XL2546 are 240Hz 1ms TN panels.
-- They vary in monitor motherboard/firmware implementations, which affect features such as overdrive, VRR, and blur reduction features.
Motion Blur is Identical in non-strobed non-VRR modes
(VRR being Variable Refresh Rate, aka GSYNC or FreeSync). When running in non-VRR non-strobed modes, they are darn near identical in amount of motion blur. XL2546 is a DyAc model which will have Blur Reduction enabled by default. In non-strobed modes with similar overdrive settings, they're all darn near exactly identical in motion blur (much like identicalness of 144Hz 1ms TN-panel monitors).
GSYNC vs FreeSync
Little is known in quality differences, but reportedly GSYNC at 240Hz is currently performing better than the unoptimized Adaptive-Sync implementation (no variable overdrive currently implemented on this specific model). If VRR is a priority at 240Hz, the cards currently favour GSYNC at this time. If you don't plan to use VRR, then this isn't relevant. For 300+fps VSYNC OFF operation, GSYNC becomes less important, but when you ramp up the detail levels, e.g. games that don't 240fps consistently -- then GSYNC is more advantageous than during 144Hz days -- when you've got mondoo headroom to 240Hz and newer games like Overwatch that can wildly fluctuate 50fps-200fps... Your decision whether or not to use GSYNC/FreeSync should be based on whether you're consistently running framerates below refresh rate. If you are, then it's a setting worth trying.
ULMB versus Blur Reduction versus DyAc
- PG258Q uses ULMB, XL2540 uses unadvertised "Blur Reduction", and XL2546 uses advertised "DyAc". ULMB is easier to set up with minimal
strobe crosstalk out of the box, while Blur Reduction/DyAc is much more adjustable. BenQ/Zowie will let you enable strobing at >144Hz at the tradeoff of more strobe crosstalk, but for refreshrate-versus-refreshrate, you can get roughly similar quality (e.g. 144Hz versus 144Hz) after about an hour of calibration (either via Service Menu or via Strobe Utility), or aim for a higher strobed refresh rate instead to reduce lag.
- The new version of
Strobe Utility now has experimential support for XL2540 and probably works with XL2546 too.
- All three monitors have strobe length adjustments (very subtle improvement in motion blur, for large tradeoff of brightness -- see
LightBoost 10% vs 50% vs 100%).
Blur Reduction Lag
This is complex to answer, but loosely speaking: The higher refresh rate for blur reduction, the lower lag the blur reduction (strobing) will cause. ULMB's 144Hz limit and fixed strobe phase limit -- creates more non-adjustable input lag than BenQ/Zowie. As a result, strobed input lag is much more adjustable, down to less than +2ms added input lag average by strobing at a higher Hz (with somewhat increase strobe crosstalk). If strobed input lag is far more important to you, BenQ/Zowie is hard to beat if you're able to tolerate slightly more strobe crosstalk for lower-lag higher-Hz blur reduction.
Lowest possible strobed lag, while avoiding microstutters
Blur reduction modes can amplify visibility of microstutters. For maximum fluidity you'll want either framerate matching framerate=Hz) or ultrahigh VSYNC OFF (>500fps preferably) to avoid the amplified microstutter effect of blur reduction. Quality is obviously best at VSYNC ON. But that's not a good option competitively. At least, you can turn on/off blur reduction. If you want to competitively play with blur reduction -- aka lowest lag with blur reduction, without the amplified microstutters -- you'll want to use VSYNC OFF and attempt as much overkill amounts of framerate you can get (e.g. 500fps-1000fps, now very easily doable with CS:GO+1080Ti) -- at a higher refresh rate such as 180Hz or 240hz -- and tolerate the increased amounts of strobe crosstalk in exchange for the world's lowest strobed lag.
Links to Amazon:
- ASUS PG258Q
- BenQ Zowie XL2540
- BenQ Zowie XL2546