OLED#11 in our OLED rankingsBright 480Hz with DisplayPort 2.1

LG UltraGear 27GX790A-B review

LG's 27-inch 1440p 480Hz WOLED with DisplayPort 2.1 and high measured brightness, now often cheaper since the 540Hz model arrived.

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Quick verdict

The 27GX790A-B is a strong 480Hz OLED that Tom's Hardware named its pick for responsiveness, reporting record-low input lag and brightness above its competitors at the time (415 nits SDR and 763 nits HDR at a 25% window). It adds DisplayPort 2.1 and a fully adjustable stand.

Its successor, the 540Hz 27GX790B-B, is faster, so this model makes most sense when it is noticeably cheaper. LG's warranty is 2 years, shorter than ASUS and Dell.

26.5″ · 1440p · 480Hz · WOLED

Buy it if

  • You play esports at 300+ fps.
  • You want strong OLED brightness.
  • It is priced below the newer 540Hz models.

Skip it if

  • You want the longest warranty.
  • You want USB-C.

Key specifications

Specifications for LG UltraGear 27GX790A-B
Exact model27GX790A-B — not the newer 540Hz 27GX790B-B
Size / aspect26.5″ / 16:9
Resolution2560×1440
Refresh rate480Hz
Dual modeNo
Panel familyOLED
Panel subtypeWOLED
Subpixel layoutUnknown
CoatingAnti-glare front layer
CurvatureFlat
BacklightNot applicable (self-emissive)
Motion technologyUnknown
Adaptive sync / VRRG-SYNC Compatible; FreeSync Premium Pro
HDRVESA DisplayHDR True Black 400
DisplayPort1x DisplayPort 2.1
HDMI2x HDMI 2.1
USB-CNone
USB portsUSB 3.0: 1 upstream, 2 downstream
KVM switchNo
AudioHeadphone jack with DTS Headphone:X; no speakers
StandFull ergonomic adjustment: tilt, height, swivel, pivot
VESA mountUnknown
Warranty2 years (US); burn-in covered 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

  • Record-low input lag in Tom's Hardware's testing.
  • 415 nits SDR and 763 nits HDR at a 25% window.
  • DisplayPort 2.1.
  • Fully adjustable stand.

Drawbacks

  • 2-year warranty.
  • Needs calibration for accurate color, per Tom's Hardware.
  • No speakers or USB-C.

What independent testing reports

MetricReported resultConditionsSource
SDR brightness415 nits25% window, variable brightness set to highTom's Hardware, July 25, 2025
HDR brightness763 nits25% windowTom's Hardware, July 25, 2025

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 480Hz each frame lasts about 2.1 ms on a sample-and-hold display. Tom's Hardware reported record-low input lag with perfect motion resolution. We did not find a documented black frame insertion mode.

Image quality and HDR

Tom's Hardware measured 415 nits in SDR and 763 nits in HDR at a 25% window, higher than competing OLEDs at the time of its test. Color needs calibration for best accuracy. WOLED holds deep blacks well in ambient light.

Connectivity, PC, and console notes

DisplayPort 2.1, two HDMI 2.1 ports, a two-port USB hub, and a headphone jack with DTS Headphone:X. No USB-C.

OLED care and warranty

LG includes pixel orbiting, a screen saver, and a refresh routine. The warranty is 2 years according to Tom's Hardware; LG's 2023 statement says US UltraGear OLED coverage includes burn-in for normal residential use.

Warranty: Tom's Hardware lists a 2-year warranty. LG stated in 2023 that its US UltraGear OLED warranty covers burn-in for normal residential use. Confirm current terms with LG. Source: TechRadar, August 11, 2023, checked September 30, 2026.

Alternatives worth comparing

Questions buyers ask

Should I buy the 27GX790A-B or 27GX790B-B?

The B model is faster (540Hz) and adds USB-C. The A model is worth it only at a clear discount.

Final recommendation

A bright, very responsive 480Hz OLED that is worth buying at a discount; otherwise step up to a 540Hz model or choose ASUS for a longer warranty.

Sources

First published . Last substantive update .