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... There are a couple of more 27-32" QD-based options on the market, but information is scarce...
One of the rare reviewers, which used to test BS thoroughly was a5hun (ApertureGrille)
I've also avoided 27" FHD panels, due to their terrible pixel density / display resolution target for common desk spaces.

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 (mostly due to the blurbusters utility)

Keep in mind that MPRT target is inversely proportional to the luminance output. This is where BenQ shines with their custom backlight solution.

A common bad practice, which frankly ruins backlight strobing, are custom implementations which implement a fixed duty cycle, which means that you require a higher vertical frequency (refresh rate) to achieve the best possible MPRT.

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:
https://blurbusters.com/benq/strobe-utility/
Viewsonic XG2431 (great adjustability due to bb util & osd settings),
BENQ XL2540, XL2546, XL2566K (great due to bb utility),

G-SYNC Module ULMB models
360Hz IPS LCD
ASUS PG259QN(R),
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
(no pulse width)
ASUS PG248Q
ACER XB241H


Notable custom backlight strobing solutions
I don't know how the new DyAc2 models (XL2546X+, XL2566X+, XL2586X, XL2586X+), which use rolling scan backlight strobing behave in terms of crosstalk & MPRT at lower refresh rates.

AOC AG246FK6's MBR+ (rolling scan backlight strobing) has a few steps to choose from (which I assume adjusts the pulse width)

MSI MAG251RX is also bearable, 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

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 (sadly KSF, decent adjustability)
(Information is scarce on the ACER XB273U F & AOC AG276QSG)

G-SYNC Pulsar models (continuation of G-SYNC FPGA) (confirmed to be QD, as per Chief)
27" QHD IPS LCD 360Hz:
ASUS XG27AQNGV
ASUS PG27AQNR
ACER XB273U F5
MSI MPG 272QRF X36
AOC AG276QSG2


Notable custom backlight strobing solutions
Note: Most of these have a fixed duty cycle, meaning that their lowest strobe duration setting is the max refresh rate one
AOC Q24G2A
MSI 274QRF-QD, G274QPF-QD, MSI Optix G273QF
GB FI32Q X
Cooler Master Tempest GP27Q
Gigabyte M27Q2 QD
Acer XB273U GX (only 'usable' at 270Hz setting), Nitro XV272U KVbmiiprzx
HP X27q, Omen 27q
ASUS XG279Q (unsure if KSF), XG27AQ (QD WLED)
LG 27GN800-B (unsure if KSF)

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


Notable custom backlight strobing solutions
Note: Most of these have a fixed duty cycle, meaning that their lowest strobe duration setting is the max refresh rate one
MSI 274URF-QD (QD), MPG321UR-QD, MPG 274URDFW E16M (rolling scan strobing, great implementation)
KTC M27P20 Pro
Benq EX3210U (QD)
Viewsonic XG320U
ASUS PG32UQ, XG32UQ, PG27UQR

5K
27" QHD IPS LCD 360Hz:
G-SYNC Pulsar models (continuation of G-SYNC FPGA) (confirmed to be QD, as per Chief)
ACER XB323QX
AOC variant — unknown model name as of Q4 2025

Notable custom backlight strobing solutions
ASUS XG27JCG (ELMB 2, rolling scan strobing but sadly KSF as per 1 and 2... will still keep it here for the sake of rarity)


Taken from various sources online, such as:
https://www.nvidia.com/en-eu/geforce/pr ... ors/specs/
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.