LG UltraGear evo GX9 39GX950B-B / ASUS ROG Strix OLED XG27UCDMG

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

ASUS ROG Strix OLED XG27UCDMG: XG27UCDMG · 26.5-inch 4K 240 Hz QD-OLED

SpecificationLG UltraGear evo GX9 39GX950B-BASUS ROG Strix OLED XG27UCDMG
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) LG—
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.

LG		—
Pixel response0.03 ms GtG

Not total input lag.

LG		—
Brightness335 nits typical; 300 nits minimum LG1000 cd/m² HDR peak

ASUS notes peak brightness may vary with colour pre-calibration; the peak is reached on a small screen area.

ASUS
Peak HDR brightness1500 nits

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

LG		—
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.

LG		—
SurfaceAnti-glare, low-reflection front polarizer LG—
CalibrationFactory calibrated; hardware-calibration ready (LG Calibration Studio) LG—
Variable refreshG-SYNC Compatible; FreeSync Premium Pro LGFreeSync Premium Pro, G-SYNC Compatible; VESA AdaptiveSync Display 240 Hz

Variable refresh matches the screen's rate to the graphics card's frame rate, reducing tearing and stutter.

ASUS
DisplayPort1 × DisplayPort 2.1; UHBR20

The graphics card and cable must support this rate.

LG		—
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.

LG		—
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.

LG		—
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.

LG		—
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 +20°/−5°, swivel ±45°, pivot ±90°, 0–120 mm height; VESA 100 × 100; 1/4-inch tripod socket

The tripod socket lets a camera or light be mounted on the stand.

ASUS
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.

LG		—
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		—
OLED careScreen saver; Image Cleaning of about 10 minutes

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

LG		—
LightingUnity Hexagon Lighting 2.0 on the back LG—
Warranty2 years; OLED panel included LG3 years (including panel burn-in)

Warranty terms may vary by country.

ASUS
Panel—26.5-inch (27-inch class) QD-OLED, 16:9, anti-reflection surface

QD-OLED pairs self-emitting pixels with a quantum-dot colour layer; each pixel switches off individually, so blacks are fully dark.

ASUS
Resolution and refresh—3840 × 2160, 240 Hz

The 4K 240 Hz signal travels over DisplayPort 1.4 with DSC compression, or over HDMI 2.1 depending on graphics-card support.

ASUS
Response time—0.03 ms (GtG)

This is the grey-to-grey pixel transition time, not total input lag.

ASUS
Contrast—1,500,000:1 (typical) ASUS
Colour—99% DCI-P3, 145% sRGB; ΔE < 2; 10-bit

Factory calibration (ΔE < 2) means colours are set close enough to target that differences are hard to see.

ASUS
HDR—HDR10; VESA DisplayHDR 400 True Black ASUS
Inputs—1 × DisplayPort 1.4 (DSC); 2 × HDMI 2.1 (FRL); 1 × USB-C (DP Alt Mode, 90 W power)

The USB-C input takes video from a laptop and charges it at up to 90 W over one cable. HDMI 2.1 suits consoles at 4K 120 Hz.

ASUS
USB hub and audio—3 × USB 3.2 Gen 1 Type-A; headphone jack ASUS
Features—ASUS OLED Care, KVM switch, Extreme Low Motion Blur, Neo Proximity Sensor, flicker-free

KVM shares a keyboard and mouse connected to the monitor between two computers. The proximity sensor dims the screen when the user leaves to reduce OLED wear.

ASUS
Power consumption—< 80 W; < 0.5 W in power saving; < 0.3 W off; 100–240 V ASUS
Dimensions and weight—With stand 61.30 × 50.94 × 16.87 cm, 7.44 kg; without stand 61.03 × 36.92 × 6.65 cm, 5.0 kg ASUS
In the box—DisplayPort, Ultra High Speed HDMI, USB 3.2 and USB-C cables; power cord; VESA mount kit; microfibre cloth ASUS