Refresh-rate marketing pushes a single number — 240, 360, 540 — as the lever that wins gunfights. The official pages from NVIDIA and ASUS, alongside measured benchmarks, tell a more graduated story: each doubling of refresh tightens scanout latency and motion clarity, but the gains compress as you climb, and a good chunk of the “540Hz feels sharper” effect comes from backlight strobing rather than the panel ticking faster.
What changed
NVIDIA’s 360Hz G-SYNC program, launched with partners Acer, Alienware, ASUS, and MSI, framed 360Hz displays as 1.5× faster than the then-standard 240Hz panels, pitched directly at VALORANT, Fortnite, Counter-Strike: Global Offensive, Rainbow Six Siegesiege. A timed, large-scale attack on a settlement — attackers try to destroy it, defenders try to hold it., and Overwatch. The same page bundles the NVIDIA Reflex Latency Analyzer, a built-in tool that measures end-to-end system latency by timing the gap between a mouse click and the resulting pixel change (gun muzzle flash) on screen — the first widely available way for a player to read their own click-to-photon latency without external hardware.
The refresh-rate ceiling then moved twice. ULMB 2 (Ultra Low Motion Blur 2) arrived as a firmware update for capable 1440p 360Hz G-SYNC monitors, delivering what NVIDIA calls “over 1000 Hz of effective motion clarity.” The mechanism is full-refresh-rate backlight strobing with Vertical Dependent Overdrive, which only flashes the backlight once each pixel has settled to its correct color. NVIDIA’s worked example is a 360Hz monitor achieving 1440Hz of effective motion clarity with ULMB 2 — the equivalent blur reduction of a hypothetical non-strobed 1440Hz panel. ASUS then pushed the panel itself: the ROG Swift Pro PG248QP, a 24.1-inch 1080p E-TN (Esports TN) panel, runs a 540Hz overclock above a 360Hz base and lists ULMB 2 delivering over 2000Hz of effective motion clarity, with a 0.2ms-rated response time and DisplayHDR 400.
The pattern is the important part: the headline number rose (360 → 540), but the largest single perceptual jump came earlier, and the later gains increasingly depend on strobing rather than raw scanout.
How it works
Two separate things shrink as refresh rate climbs. The first is scanout latency — the time a frame takes to paint top-to-bottom. At 144Hz a refresh cycle is ~6.94ms; at 240Hz ~4.17ms; at 360Hz ~2.78ms; at 540Hz ~1.85ms. Because the GPUGPU. Graphics Processing Unit — the chip that renders the game's visuals; the main driver of framerate and image quality. can hand the next frame off only after the current scanout completes, faster scanout directly tightens the floor on display-side latency, and it benefits you even when your framerateframerate. How many images (frames) the game shows per second; higher = smoother motion. 60 fps is a common target. is well below the refresh ceiling — 100fps on a 360Hz panel is transmitted to the monitor in 1/360s rather than 1/144s, so VRR-capped play at sub-max framerates still rides the faster scanout.
The second is motion clarity. LCD motion blur comes from “sample-and-hold” — a frame is held on screen until the next one arrives, and your eyes smear the held image across the saccade. Two fixes exist: raise the refresh rate so each held frame is shorter (less smear), or strobe the backlight so the eye only sees the settled frame for an instant. NVIDIA’s ULMB 2 page is explicit about the math: Effective Motion Clarity = Refresh Rate × (1 / Duty Cycle). A 360Hz monitor at a 25% duty cycle hits 1440Hz effective; the PG248QP’s strobed 540Hz clears 2000Hz effective. Strobing converts a 360–540Hz panel into something that reads like a four-figure panel, which is why the official spec sheets lean on it.
ASUS’s E-TN panel is the other half. The PG248QP spec sheet claims E-TN is approximately 50% more responsive than traditional TN panels. Measured by TechSpot, the PG248QP’s Normal overdrive mode averaged 1.8ms GtG with near-zero overshoot at 540Hz (86% refresh compliance), and held 1.9ms at 360Hz, 2.3ms at 240Hz, 2.5ms at 144Hz and 60Hz via variable overdrive. That is the fastest LCD TechSpot had tested at the time — about 0.5ms faster than the 360Hz PG27AQN at peak, and over 50% faster than BenQ’s 360Hz XL2566K. OLEDs remain roughly 5–6× faster in raw GtG, but no OLED ships at 540Hz, so at peak refresh the strobed LCD clears more motion blur than a 240Hz OLED can.
There are hard caveats in the official pages. The PG248QP needs an NVIDIA RTX 20-series or above GPU and the latest Windows to unlock 540Hz; on AMD GPUs, 540Hz works but variable refresh rate caps at 500Hz, an 8% delta. The monitor’s HDMI ports are 2.0, limiting them to 240Hz — full-rate use wants the DisplayPort 1.4 with DSC input. And ULMB 2 on this specific monitor only engages down to 360Hz; below that the option greys out, so if your game won’t hold ~500fps you lose strobing entirely.
What it means
The diminishing-returns curve is real but it is not flat. NVIDIA’s own framing is incremental — 240Hz was a step, 360Hz is 1.5× faster than 240Hz, and the company cited a roughly 4% relative flick-shot improvement going from 240Hz to 360Hz in its internal esports study. The reputable-display-analysis reading is that the 1–10% improvement band per step is realistic when you hold GPU and game constant, and that the biggest subjective jump in the modern stack is 144Hz → 360Hz, not 360Hz → 540Hz. TechSpot’s reviewer put the 144Hz-to-540Hz delta as “night and day” even for desktop use, called 240Hz-to-540Hz a clear but smaller upgrade, and noted that 540Hz over 360Hz was “noticeable” but not enough to justify the price jump alone.
The practical consequence for competitive shooters is that refresh rate buys you two things and they decouple. In CS2 and Valorant, where framerates of 300–500+ are achievable and matches turn on a single tracked angle, the faster scanout of 360–540Hz tightens the click-to-photon floor and the motion clarity of a strobed frame lets you read a moving target during a flick. In Marvel Rivals and other hero shooters where you routinely trade at closer ranges with more on-screen motion, the motion-clarity half matters more than the absolute latency half — and that half is exactly what ULMB 2 and E-TN response times deliver. The reflex argument, the one NVIDIA builds its whole 360Hz page around, is that you do not need to be a pro to feel responsiveness; you need to be playing CPU-bound, high-framerate titles to measure it.
A second consequence of the strobing path is that you cannot use it and variable refresh at the same time. NVIDIA’s ULMB 2 enable instructions are explicit: you disable G-SYNC variable refresh in the NVIDIA Control Panel first, then switch ULMB 2 on in the monitor’s OSD. Strobing needs a fixed refresh to time the backlight pulse to the settled frame, so the panel runs at a locked 360Hz or 540Hz rather than riding your framerate. That forces a real choice in CPU-bound shooters: run VRR for tear-free variable frames, or run a fixed strobed refresh for maximum motion clarity and accept that you must hold framerate near the refresh ceiling or the strobing artifacts (stutter when framerate drops below refresh, double-images when it cannot sync). On the PG248QP, ULMB 2 only engages down to 360Hz, so a player who cannot sustain ~360fps loses strobing entirely — BenQ’s competing DyAc+ strobes down to 100Hz, which is why TechSpot flagged it as the better pick for anyone whose framerate wanders the middle of the range.
The honest buyer’s read: 144Hz remains a competent floor; 240Hz is the price-perf sweet spot for most; 360Hz with G-SYNC and Reflex Analyzer is where the latency and motion-clarity story gets genuinely competitive; 540Hz E-TN is a halo product whose real contribution is proving the strobed-LCD motion-clarity ceiling can clear OLEDs at peak refresh, at the cost of TN viewing angles, a 1080p resolution, HDMI ports capped at 240Hz, and a price that TechSpot concluded was hard to justify for anyone who is not paid to play.