I need a 24"-27" monitor with decent 120hz strobing and no red KSF phosphor !

[alexander1986]

A while back I bought some asus 27" ips (forgot the model now) and I could not stand the red fringing when using ELMB, did some research and found out it is due to some red KSF phosphor thing!


was wondering how common is this today in 2025 is it being used in many new IPS monitors?

most of all I am looking for some tips on a cheap 24-27" monitor without this red KSF phosphor,
all I really need is good strobing at 120-144hz but preferrably a cheap monitor if possible !

if anyone got some tips and/or testufo screenshots from some monitor that would be very helpful,

thanks!

[Discorz]

XG2431 might suit your needs well. It's a valid option if you're looking for those specs. There is a new, detailed, multi-page review on Blur Busters website with pursuit photos, charts and all.

https://www.blurbusters.com/xg2431-discorz

Vast majority of new monitors use KSF/PFS backlights for wider color gamut. It is only recently that we're starting to see more QD backlight options that don't suffer from such artifacts. XG2431 uses neither of those, nor is the gamut particularly wide, but the strobing mode performs very well at lower refresh rates.

[kyube]

Disclaimer: If it's not here, it likely doesn't have a good backlight strobing implementation as of Q4 2025, YMMV with each one of these
I will add that reviews of backlight strobing implementations are very subpar and barely anyone tests it properly.
This is only based on the seldom good data available online, hefty speculation & extrapolation on my part...
There are a couple of more 27-32" QD-based options on the market, but the information is too scarce...
One of the rare reviewers, which used to test BS thoroughly was a5hun (ApertureGrille)
I've also avoided mentioning 27" FHD models here due to their terrible pixel density / display resolution target for common desk depths.

The best backlight strobing modes are ones which have:
• YAG phosphor WLED backlight or QD-based WLED backlight (KSF/PFS leads to red fringing)
• Adjustable pulse width parameters (ideally in 2 decimal points and <1ms MPRT, but the former part is rare)
• Properly adjustable overdrive in steps of 0–100
• Retro 60Hz mode (rare, I personally avoid this due to severe light flicker)
• Bonus points if rolling scan (rare models on the market)

The good implementations are usually ones which employ ULMB (Nvidia-tuned), PureXP or DyAc (1/+) (mostly due to the blurbusters utility)
ULMB2 is sadly either crippled with red fringing (KSF/PFS WLED backlight) or lacks adjustable PW (new Pulsar models) in the select models it's offered in.

Keep in mind that 'on' strobe period is inversely proportional to the luminance output. This is where BenQ shines with their custom backlight solution & large voltage boosting

A common bad practice, which ruins backlight strobing IMO, are custom implementations which implement a fixed duty cycle / pulse width, which means that you require a higher vertical frequency (refresh rate) to achieve the best possible eye-tracked motion performance.

§ — rolling scan backlight strobing (CRT-like waveform)

See this thread to see how waveforms differ between different types of PWM dimming (global or rolling scan single strobe, multi-strobe...)

Here's how a trinitron CRT behaves @ 120Hz, going up to 1700cd/m²!
SVM data for CRT

Here's a list of display which have a good backlight strobing implementation up to Q4 2025:
note: I've skipped 27" FHD models, as they're a terrible PPD target for desktop use

FHD:
BB utility
Link to models which are supported by it: https://blurbusters.com/benq/strobe-utility/
Viewsonic XG2431

G-SYNC Module ULMB(1) models
360Hz IPS LCD
ASUS PG259QN,
Dell AW2521H,
MSI NXG253R,
Lenovo Y25G-30,
AOC AGON PRO AG254FG,
Viewsonic XG251G
Acer Predator X25
LG 25GR75FG

240Hz TN LCD
(have pulse width adjustments)
OMEN X25,
Dell AW2518H,
Viewsonic XG2560,
MSI NXG252R, NXG251R,
ACER XB252Q, XN253QX,
(have no pulse width adjustments)
AOC AG251FG & ASUS PG258Q

180Hz TN LCD
(has pulse width adjustments)
AOC G2460PG
ASUS PG248Q
(no pulse width)
ACER XB241H

DyAc (1)
144Hz LCD
(Note: There are older models, but they aren't labeled as DyAc but rather with the generic term of “motion blur reduction”)
BenQ XL2411K

240Hz TN LCD
BenQ XL2536, XL2546

DyAc+
(The assumption is that it offers much larger voltage boost when strobing)
240Hz TN LCD
BenQ XL2546K
360Hz TN LCD
BenQ XL2566K (benefit of having the ability to use Blurbusters utility); Confirmed voltage boost up to 2000cd/m²

DyAc2 (§)
I don't know how the new DyAc2 models (XL2546X, XL2546X+, XL2566X+, XL2586X, XL2586X+), which use rolling scan backlight strobing behave in terms of crosstalk & eye-tracked clarity at 100–x refresh rates (<100hz is double-strobed, since DyAc came to the market)
XL2546X — (DyAc Premium is ~9,4PW; which would place 240Hz @ 0,8836 ms MPRT; DyAc High = 18.3% PW)
XL2586X+ — 1200 & 1400cd/m² voltage boosting confirmed. SVM data
XL2566X+ — 800–1000cd/m² (depending on DyAc 'High' or 'Premium') voltage boosting confirmed
It seems that the implementation details differ, based on the panel.

Notable custom backlight strobing solutions
BenQ XL2540X+ — BenQ's "Blur Reduction" (likely); uses 24.1" TN panel
BenQ XL2540K — BenQ's "Blur Reduction" (likely); uses 24.5" TN panel
BenQ XL2540 — BenQ's "Blur Reduction"; uses 24.5" TN panel (0,5ms MPRT @ 200cd/m² @ 240 Hz; 0,25ms MPRT @ 100cd/m² @ 240 Hz)
BenQ XL2411P — BenQ"s "Blur Reduction"; uses 24" TN panel (60hz single-strobe)
AOC AG246FK6 / CS24A MBR+ (§) has the standard MBR steps to choose from, which adjust the PW;I don't know the lowest PW it targets
MSI MAG251RX is also bearable at it's maximum vertical frequency setting (240Hz), but inferior over the ones above, though I'll mention it.


QHD:
GSYNC module (ULMB capable)
24" QHD TN LCD 165Hz
(has pulse width adjustments)
Dell S2417DG
(have no pulse width adjustments)
Acer Predator XB241YU,
AOC AGON AG241QG

27" QHD TN LCD 144-165Hz
Lenovo Y27GQ-20
ASUS PG278Q, PG278QR
Dell S2716DG

27" QHD IPS LCD 165Hz:
Acer XB270HU, XB271HU
AOC AG273QG, AG273QCG
ASUS PG279Q, PG279QR, PG279QE
Viewsonic XG2703-GS, XG2760, XG270QG (0,875–0,375ms @ 100–53cd/m² @ 120Hz; KSF)

27" QHD TN LCD 240Hz:
Lenovo Y27GQ-25 (likely KSF)

27" QHD IPS LCD 240Hz:
Viewsonic XG271QG (likely ksf)
Acer XB273U NX (don't know if QD or KSF)

27" QHD IPS LCD 360Hz:
ASUS PG27AQN (KSF/PFS, extremely well done implementation; 25–5% PW adjustments (100-10; steps of 10); fixed to 360, 240 & 120Hz; 0,7–0,125ms MPRT @ 270cd/m²–24cd/m² @ 360Hz)
(Information is scarce on the ACER XB273U F & AOC AG276QSG; likely performs akin to the above model)

G-SYNC Pulsar models (continuation of G-SYNC FPGA) (YAG phosphor, not QD)
(PW adjustments in fixed refresh rate backlight strobing mode added with FW update; DP1.4 only & NVidia dGPU only; HDMI 2.0 like predecessor)
27" QHD IPS LCD 360Hz: (§)
ASUS XG27AQNGV (§)
ACER XB273U F5 (§)
MSI MPG 272QRF X36 (§)
AOC AG276QSG2 (§)
Note: Has some flaws, see here

DyAc (1)
BenQ XL2735 (note: The XL2730Z or XL2730 aren't DyAc models, but offer a feature labeled “motion blur reduction” instead; the latter can use the Blurbusters utility)

Notable custom backlight strobing solutions
Note: Most of these below have a fixed duty cycle, meaning that their lowest 'on' strobe period setting is only achievable at the maximum refresh rate of the model
BenQ XL2730Z (MBR model; adjustable pulse width as per TFTCentral; 0,5ms MPRT @ 51cd/m² @ 144Hz; 0,75ms MPRT @ 90,2cd/m²; 1ms MPRT @ 126cd/m² @ 144Hz)
ASUS XG27ACS (ELMB; lvl=5 → 0,556ms @ 86 cd/m² @ 180 Hz; ~10% PW; sadly KSF/PFS)
AOC Q24G2A (likely ~29% PW @ MBR=20 @ 165Hz, leads to ~1,75ms MPRT), AG273QZ (KSF/PFS TN; 0,5ms MPRT @ 67cd/m² @ 240Hz; as per TFTCentral)
MSI 274QRF-QD, G274QPF-QD, MSI Optix G273QF (Note: G274QPF-QD > 274QRF-QD >> 274QRF-QD E2 in terms of achievable MPRT. 21% vs 28% vs 41.1% PW difference OR 1,2353 vs 1,69 ms vs 2,283 ms MPRT)
MSI 274QPF X30MV (MPRT; 21% PW @ 300,240Hz → 0,7 & 0,825 ms MPRT; MiniLED VA, rolling scan)
Acer XB273U GX (only 'usable' at 270Hz setting), Nitro XV272U KVbmiiprzx, XB273U KF (likely 0,5ms MPRT @ 300Hz; QD-based)
GB FI32Q X (likely ~30% pulse width; akin to M27Q-X; QD-based, ~1,25ms MPRT @ 240Hz)
HP X27q, Omen 27q (panel swap sheningans; be aware)
Cooler Master Tempest GP27Q (3 distinct settings, as per TFTCentral)
Gigabyte M27Q2 QD (likely ~30% PW)
ASUS XG279Q (unsure if KSF), XG27AQ (QD WLED)
LG 27GN800-B (unsure if KSF)
ASUS PG329Q (adjustable pulse width/length, as per TFTCentral)


UHD
G-SYNC Module ULMB model
(has pulse width adjustments)
Viewsonic XG321UG (reviews claim that it lacks ULMB support, but manual claims that it supports it)


Notable custom backlight strobing solutions
Note: Most of these have a fixed duty cycle, meaning that their lowest 'on' strobe period setting is the max refresh rate one
KTC M27P6 (The absolute best 27" 4K backlight strobing model on market, variable PW depending on refresh rate chosen; Targets fixed 0,75ms MPRT)
MSI 274URF-QD (QD), MPG321UR-QD, MPG 274URDFW E16M (§, ok clarity)
KTC M27P20 Pro
Viewsonic XG320U
ASUS PG32UQ (adjustable pulse width/length, as per Tftcentral), XG32UQ (same as pg), PG27UQR (same as previous 2)
Benq EX3210U (QD) (~I'd skip this one over other options...; 2,083ms MPRT @ 144Hz is mediocre...; It's a 30% pulse width solution)

5K
G-SYNC Pulsar models (continuation of G-SYNC FPGA)
ACER XB323QX (likely not coming in 2026)
AOC variant — unknown model name as of Q4 2025


Notable custom backlight strobing solutions
ASUS XG27JCG (ELMB 2, § but sadly KSF as per 1 and 2... will still keep it here for the sake of rarity; should be a great MPRT target @ LVL=5; Likely lowest pulse width 5K solution on the market)
MSI 271KRAW16 (QD-based, will likely target ~30% pulse width as well... doubt it'll be lower.)
LG 27GM950B (QD-based, unknown pulse width. See this video for example)
AOC AGP277KX (MBR+ §, sadly KSF; targets ~30% pulse width, which is on the blurrier side...)



Taken from various sources online, such as:
https://chimolog.co/category/%e3%82%b2% ... %e3%83%bc/ (Amazing data)
https://www.nvidia.com/en-eu/geforce/pr ... ors/specs/
Bilibili reviewers (amazing data)
viewtopic.php?t=4555
https://blurbusters.com/faq/120hz-monitors/
https://www.displayninja.com/new-monitors/
& online reviews by RTINGS, TFTCentral, MUB/HUB, a5hun, Bijan Jamshidi & many other sources.

[mango87]

I didn't realize this was a thing until I bought the MSI MAG 275QPF X30 and enabled strobing. There's a noticeable red trail. Now I have to look out for which IPS monitors have QD backlights.

[bobbie424242]

Would the AOC U27G4R (dual 4K / 160Hz, 1080p / 320Hz) fit that list ?

It has a WLED backlight, MBR with 20 levels with VRR disabled and "MBR Sync" (on/off toggle) with VRR enabled.

I have this monitor since 3 days and it is very decent.

[kyube]

Would the AOC U27G4R (dual 4K / 160Hz, 1080p / 320Hz) fit that list ?

It has a WLED backlight, MBR with 20 levels with VRR disabled and "MBR Sync" (on/off toggle) with VRR enabled.

I have this monitor since 3 days and it is very decent.

KSF WLED backlight is not optimal due to: https://blurbusters.com/beautiful-red-p ... ion-badly/
Hence why I mentioned YAG phosphor or QD-based WLED as the only viable solutions.

[bobbie424242]

KSF WLED backlight is not optimal due to:
Hence why I mentioned YAG phosphor or QD-based WLED as the only viable solutions.

How do you know that AOC monitor uses KSF phosphor (I could not find what manufacturer panel model it uses exactly) ?
Is it the very wide gamut and advertised DCI-P3 coverage (95%) that strongly hints at KSF phosphor ?

[Chief Blur Buster]

KSF creates problems for MiniLED, local dimming and strobe backlights. That's why KSF is being deprecated in favor of quantum dots nowadays.

There is an article at www.blurbusters.com/red-phosphor

[kyube]

How do you know that AOC monitor uses KSF phosphor (I could not find what manufacturer panel model it uses exactly) ?
Is it the very wide gamut and advertised DCI-P3 coverage (95%) that strongly hints at KSF phosphor ?

It's usually surmounted to one of the following approaches:
1) Find a reviewer which shows SPD curve (best approach)
2) Find a reviewer which shows color gamut (as you've suspected, 95% is usually a indicator of KSF)
3) Find a reviewer which does UFO pursuit photographs with backlight strobing enabled

For that display, here's the KitGuru review
Here's also techteamGB's review

Here's how a QD-based monitor stacks up:
techteamGB's MPG321QRF-QD review

The post you've quoted initially was a speculation on my part.

EDIT: Here's also a reviewer which showcases a SPD graph, confirming the use of a KSF/PFS-based WLED backlight solution:

[bobbie424242]

Thank you for clarifying.

I bought this monitor on Black Friday at an interesting price after seeing the KitGuru review and evaluating other options. It replaced the 4K 60Hz G-Sync monitor that I purchased in 2017 (and that was back then very high end). I specifically did not want OLED and did not care for HDR (mini-LED) but wanted high refresh rates at 4K and was intrigued by the 1080p dual mode.

My older 4K 60 Hz monitor is still very good and I have recycled it for use with my work laptop.