OLED#5 in our OLED rankingsBest matte 540Hz alternative

LG UltraGear 27GX790B-B review

LG's 27-inch 1440p 540Hz tandem WOLED with a 720p 720Hz mode and a matte coating: the competitive OLED for rooms with glare.

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Quick verdict

The 27GX790B-B is the natural alternative to our competitive OLED pick for people whose desk faces a window or bright lights. It uses a 4th-generation tandem WOLED panel at 540Hz, like the ASUS PG27AQWP-W, but with a standard matte anti-glare coating instead of gloss, and adds a USB-C input.

The 720Hz mode runs at 1280×720, which Tom's Guide found very blurry, and its DisplayPort 2.1 input runs at UHBR13.5, so full specs need compression. LG's burn-in coverage is 2 years in the US according to its 2023 statement, shorter than the 3 years ASUS and Dell offer.

26.5″ · 1440p · 540Hz · dual mode 720p at 720Hz · WOLED (4th gen, Primary RGB Tandem)

Buy it if

  • You want 540Hz OLED speed and your room has windows or lamps behind you.
  • You want a USB-C video input.
  • Your PC can hold very high frame rates.

Skip it if

  • Your lighting is controlled; the glossy PG27AQWP-W shows deeper blacks and has a 3-year warranty.
  • You rarely exceed 240 fps.
  • You want a long burn-in warranty.

Key specifications

Specifications for LG UltraGear 27GX790B-B
Exact model27GX790B-B — not the older 480Hz 27GX790A-B
Size / aspect26.5″ / 16:9
Resolution2560×1440
Refresh rate540Hz
Dual mode1280×720 at 720Hz
Panel familyOLED
Panel subtypeWOLED (4th gen, Primary RGB Tandem)
Subpixel layoutUnknown (4th-gen WOLED)
CoatingMatte anti-glare
CurvatureFlat
BacklightNot applicable (self-emissive)
Motion technologyUnknown
Adaptive sync / VRR48–540Hz (48–720Hz in HD mode); G-SYNC Compatible, FreeSync Premium Pro, HDMI 2.1 VRR
HDRVESA DisplayHDR True Black 500
DisplayPort1x DisplayPort 2.1 (UHBR13.5; DSC needed for the full spec)
HDMI2x HDMI 2.1
USB-CDisplayPort Alt Mode (power delivery not verified)
USB ports2x USB 3.0 downstream
KVM switchUnknown
AudioHeadphone jack
Stand110mm height, tilt, pivot
VESA mount100 x 100 mm
Warranty2 years including burn-in (US), per LG's 2023 statement

Specifications are manufacturer-stated unless marked as measured. “Unknown” means we could not verify the value, not that it is zero or absent.

Advantages and drawbacks

Advantages

  • 540Hz at 1440p on a 4th-gen tandem WOLED panel.
  • Matte coating handles reflections better than glossy rivals.
  • USB-C with DisplayPort Alt Mode.
  • DisplayHDR True Black 500 and bright HDR highlights.

Drawbacks

  • 720Hz mode drops to 1280×720 and looks soft.
  • DisplayPort 2.1 at UHBR13.5 still needs DSC for the full spec.
  • 2-year US warranty, shorter than ASUS and Dell.
  • Matte coating looks slightly grainier than glossy.

What independent testing reports

MetricReported resultConditionsSource
SDR brightness249 nitsTom's Guide SDR measurementTom's Guide, April 30, 2026
HDR brightness561 nits10% windowTom's Guide, April 30, 2026

These are third-party results, not our tests. Different outlets use different methods, so compare numbers only within the same source.

Motion, response, and latency

At 540Hz each frame lasts about 1.9 ms on a sample-and-hold display, and OLED's near-instant response means there is almost no additional smear. As with every 540Hz monitor, you only see the full benefit when your game runs near 540 fps. The 720Hz mode trades resolution for speed at 1280×720. We did not find attributable input-lag measurements for this exact model.

Image quality and HDR

LG specifies about 335 nits typical SDR brightness and HDR peaks of 1,500 nits in a 1.5% window. Tom's Guide measured 249 nits in SDR and 561 nits at a 10% HDR window, with very wide color gamut coverage. The matte coating diffuses reflections, which helps in bright rooms but lifts blacks slightly compared with glossy tandem panels.

Connectivity, PC, and console notes

One DisplayPort 2.1 (UHBR13.5), two HDMI 2.1 ports, USB-C with DisplayPort Alt Mode, and two USB downstream ports. TFTCentral notes UHBR13.5 is not enough for the full spec without DSC.

OLED care and warranty

LG includes standard OLED care routines. Burn-in coverage is 2 years in the US according to LG's 2023 statement, for normal residential use; confirm the current terms with LG before buying.

Warranty: LG stated in 2023 that its US UltraGear OLED warranty of 2 years covers burn-in for normal residential PC use, excluding commercial use. This is an older statement; confirm current terms with LG. Source: TechRadar, August 11, 2023, checked September 30, 2026.

Alternatives worth comparing

Questions buyers ask

Is the 720Hz mode 1080p?

No. TFTCentral notes LG's product page lists 1080p in one place, but the mode runs at 1280×720 (HD), which reviewers confirm.

Final recommendation

Choose the 27GX790B-B when you want 540Hz OLED speed and your room needs a matte screen. In a controlled room, the ASUS PG27AQWP-W remains our pick for its deeper blacks and longer warranty.

Sources

First published . Last substantive update .