LG UltraGear evo GX9 39GX950B-B / LG UltraGear 27GX790A-B

LG UltraGear evo GX9 39GX950B-B: 39GX950B-B · 38.86-inch · 5K2K · black

LG UltraGear 27GX790A-B: 27-inch class (26.5-inch) QHD 480 Hz OLED

SpecificationLG UltraGear evo GX9 39GX950B-BLG UltraGear 27GX790A-B
Release year20262025
Display38.86-inch OLED · 5120 × 2160 · 21:9 LG—
Curvature1500R LG—
Pixel pitch0.1776 × 0.1776 mm LG—
Refresh rate165 Hz (5120 × 2160) LG480 Hz

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

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Dual-Mode330 Hz at 2560 × 1080 in the 21:9 modes; 330 Hz at 1920 × 1080 in the 16:9 modes

The product page calls this mode QHD in one place and WFHD in another; the resolutions in the manual were used. Exit the game before changing the mode.

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Pixel response0.03 ms GtG

Not total input lag.

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Brightness335 nits typical; 300 nits minimum LGTypical 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.

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Peak HDR brightness1500 nits

Peak figure LG states under internal test conditions; not sustained full-screen brightness.

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HDR formatsHDR10; VESA DisplayHDR True Black 500; no Dolby Vision LG—
Colour coverageDCI-P3 99.5% typical, 94% minimum (CIE1976); 1.07 billion colours LG—
Contrast ratio1,850,000:1 typical; 1,480,000:1 minimum

Manufacturer figure.

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SurfaceAnti-glare, low-reflection front polarizer LG—
CalibrationFactory calibrated; hardware-calibration ready (LG Calibration Studio) LG—
Variable refreshG-SYNC Compatible; FreeSync Premium Pro LGVESA 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.

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DisplayPort1 × DisplayPort 2.1; UHBR20

The graphics card and cable must support this rate.

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HDMI2 × HDMI 2.1

The menu has 2.1(PC) and 2.1(AV) compatibility options. The product page connectivity table omits the HDMI count; the two inputs in the manual were used.

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USB-C input1 × USB-C; video, data and up to 90 W power

The manual lists DP Alternate Mode and Power Delivery. The port does not power the monitor; the adapter is required.

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USB hubUSB-C upstream; 2 × downstream USB 3.2 Gen 2

The manual says the downstream ports run at USB 2.0 over a USB-C to USB-C cable and USB 3.0 over a USB-C to USB-A cable.

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Multiple sources2 × PBP and PIP; no built-in KVM LG—
Audio2 × 7 W speakers; 4-pole headphone output; AI Sound LG—
StandTilt −8° / +15°; ±30° swivel; 110 mm height adjustment

The manual does not describe pivot rotation.

LG		Tilt -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.

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Wall mount100 × 100 mm; 4 × M4 × L10 screws; optional LSW149 plate LG—
Dimensions921.4 × 605.4 × 322.8 mm with stand (up); 921.4 × 495.4 × 322.8 mm (down); 921.4 × 405.0 × 118.7 mm without stand

Width × height × depth.

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Weight10.7 kg with stand; 6.8 kg without LG—
PowerExternal adapter; 40.3 W on-mode in SDR, 45.9 W in HDR

On-mode power demand from the product information sheet.

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

The sheet does not list typical power consumption.

LG
OLED careScreen saver; Image Cleaning of about 10 minutes

The manual states that prolonged use can cause permanent brightness reduction and image retention.

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LightingUnity Hexagon Lighting 2.0 on the back LG—
Warranty2 years; OLED panel included LG—
Model—27GX790A-B (US version 27GX790A-B.AUS)

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

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Panel—26.5-inch (27-inch class) OLED, 16:9

The actual viewable diagonal is 26.5 inches.

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Resolution and pixel pitch—2560 × 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.

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Response time—0.03 ms (GtG)

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

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Contrast—1,500,000:1 (typical)

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

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Colour—DCI-P3 98.5% (CIE 1976); 10-bit (1.07 billion colours)

The sheet lists a paper calibration report in the box.

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HDR—HDR10; VESA DisplayHDR True Black 400

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

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Screen surface—Anti-glare, low-reflection front polariser LG
Inputs—2× 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.

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

No built-in speakers are listed.

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Burn-in care—OLED 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.

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Size and weight—With 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.

LG
In the box—Power cord, DisplayPort 2.1 cable, HDMI 2.1 cable, USB A-to-B cable, paper calibration report LG