Monitors · 2025 · LG

LG UltraGear 27GX790A-B

LG's 27-inch QHD OLED monitor for competitive gaming. It offers 480 Hz refresh, 0.03 ms GtG, DisplayHDR True Black 400 and DisplayPort 2.1 plus HDMI 2.1 inputs. Tests praise motion clarity and colour accuracy; SDR brightness is limited, the gamut is narrower than QD-OLED and there is no USB-C or speakers.

27-inch class (26.5-inch) QHD 480 Hz OLED

Specifications

SpecificationValue
Model27GX790A-B (US version 27GX790A-B.AUS)

LG’s US spec sheet carries a 2024 copyright; LG Brazil lists the model as a 2025 product.

Panel26.5-inch (27-inch class) OLED, 16:9

The actual viewable diagonal is 26.5 inches.

Resolution and pixel pitch2560 × 1440 (QHD); 0.2292 mm pixel pitch

QHD at 27 inches means lower pixel density than 4K; small text looks less crisp but high frame rates are easier to reach on the GPU.

Refresh rate480 Hz

480 Hz means up to 480 frames per second; seeing that benefit requires the game and GPU to deliver close to 480 fps.

Response time0.03 ms (GtG)

Grey-to-grey pixel transition time; it is not input lag.

BrightnessTypical 275 cd/m² (min 250); HDR peak at 1.5% APL typical 1,300 cd/m² (min 1,040)

1,300 nits applies only to small highlights covering 1.5% of the screen; on a full white screen OLED automatic brightness limiting kicks in.

Contrast1,500,000:1 (typical)

OLED pixels can switch fully off, so black level is near zero; LG’s page notes the figure is measured at 25% APL.

ColourDCI-P3 98.5% (CIE 1976); 10-bit (1.07 billion colours)

The sheet lists a paper calibration report in the box.

HDRHDR10; VESA DisplayHDR True Black 400

True Black is the VESA HDR tier for very low black-level displays such as OLED.

Variable refreshVESA AdaptiveSync; NVIDIA G-SYNC Compatible; AMD FreeSync Premium Pro

Variable refresh matches the panel to the GPU frame rate to reduce tearing and stutter. LG’s page also lists VESA ClearMR 21000 certification.

Screen surfaceAnti-glare, low-reflection front polariser
Inputs2× HDMI (HDMI 2.1 FRL compliant); 1× DisplayPort 2.1

FRL is the high-bandwidth transfer mode of HDMI 2.1. There is no USB-C video input.

USB and audioUSB 3.0: 1 upstream, 2 downstream; 4-pole headphone out (sound + mic); DTS Headphone:X

No built-in speakers are listed.

StandTilt -5°/15°; swivel -30°/30°; height 110 mm; clockwise pivot; VESA 100 × 100

It has a tool-free 1Click stand mount and hexagonal RGB lighting on the back.

PowerExternal adapter, 100–240 V; under 0.5 W in sleep, under 0.3 W off

The sheet does not list typical power consumption.

Burn-in careOLED Care

LG says the feature helps prevent burn-in from static high-contrast images left on screen for long periods but may not prevent all image retention.

Size and weightWith stand 23.8 × 22.8 × 9.8 in (raised), 20.5 lb; without stand 23.8 × 13.8 × 1.8 in, 11.2 lb

About 9.3 kg with stand, about 5.1 kg without.

In the boxPower cord, DisplayPort 2.1 cable, HDMI 2.1 cable, USB A-to-B cable, paper calibration report

From the manufacturer

LG says OLED Care helps prevent burn-in but may not prevent all image retention. LG Electronics USA

Strengths and limitations

  • In PCWorld's test motion clarity at 480 Hz was the standout; default colour temperature measured 6400 K with 2.2 gamma, and colour accuracy was better than most OLEDs. Sustained SDR brightness around 250 nits can look dim in a sunny room, and the gamut is narrower than QD-OLED rivals. “Dirty screen effect” on grey fields and dark-mode apps was more visible than on most OLEDs. There is no black frame insertion, USB-C or speakers.

    Matthew S. Smith, 21 February 2025; LG sent a replacement after the reviewer reported a display issue on the first unit.

    PCWorld: LG UltraGear 27GX790A-B review

Owner experiences and issues

  • Walmart's page shows 28 reviews from 32 ratings; the three visible texts are positive. Two “Seller Verified Purchase” reviews (December 2025, March 2026) praise the black levels, HDR and 480 Hz smoothness with G-SYNC. Some reviews are syndicated from LG sites and labelled promotional; the 2- and 3-star review texts are not shown.

    Three visible reviews; two syndicated from LG, one an Influenster promotion. The page does not state the model code; two reviews refer to the 27GX790A.

    Walmart: LG UltraGear 27GX790A-B 480 Hz OLED customer reviews

Tags

2025LGULTRAGEAROLED480-HZOYUN-MONITORUQHD

Compare

Sources

  1. LG Electronics USA: 27GX790A-B specifications sheet
  2. LG Brasil: UltraGear 27GX790A-B product page
  3. PCWorld: LG UltraGear 27GX790A-B review
  4. Walmart: LG UltraGear 27GX790A-B 480 Hz OLED customer reviews