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The LG UltraGear OLED 27GX790B-B is an exceptional specialist gaming monitor, not a flawless all-purpose display. Its headline feature is a choice between QHD (1440p) at up to 540Hz and HD (720p) at up to 720Hz. That makes it compelling for competitive PC players who can use extreme refresh rates and accept a lower resolution when they want the fastest mode. OLED contrast and sharp motion are major strengths; VRR flicker, text fringing, potential burn-in, and modest USB-C power delivery deserve attention before buying.
What the LG 27GX790B-B offers
LG identifies the 27GX790B-B as a 27-inch UltraGear OLED gaming monitor. Its two operating modes trade image detail for refresh rate: the native QHD mode reaches up to 540Hz, while the HD mode reaches up to 720Hz. The 720Hz figure is not available at 1440p, so it is most relevant to players who value maximum refresh over resolution in supported games.
LG lists a 0.02ms gray-to-gray response time, DisplayPort 2.1, VESA ClearMR 21000, DisplayHDR True Black 500, NVIDIA G-SYNC compatibility, and AMD FreeSync Premium Pro. These are manufacturer-listed specifications, not independent measurements. See the LG product page.
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How it performs for gaming
540Hz at 1440p or 720Hz at 720p
The central buying decision is whether your games and hardware can make useful use of the added refresh and whether you are comfortable with the resolution drop. At 1440p, the monitor pairs high detail with a 540Hz ceiling. Switching to 720p raises that ceiling to 720Hz but makes the image less detailed. The faster mode is a specialized option rather than a free upgrade.
#1 Best Overall
- LG UltraGear OLED Goes Glossy - Experience ultra-smooth, tear-free gameplay with up to 240Hz refresh rate and 0.03ms response time on a glossy, bright 27” QHD OLED display. React instantly, spot every detail, and outpace your opponents in every frame with outrageous speed and clarity.
- Next-Level OLED Brightness, for Next-Level Play - The brilliant OLED display brings every scene to life with jaw-dropping color and intensity. Delivering a standard 275 nits of brightness and peaking at 1300 nits, your games shine with vivid clarity—keeping dark corners detailed, explosions dazzling, and the action always visible no matter the environment.
- VESA DisplayHDR True Black 400 - An OLED display with VESA DisplayHDR True Black 400 and a 1.5M:1 contrast ratio deliver deep blacks and dazzling highlights, so you catch every hidden detail in dark scenes and every spark in the bright ones. With up to 98.5% DCI-P3 color, your worlds burst with vibrant intensity—making every game feel more alive.
- Three UL Certifications. One Clear Advantage for Eye Comfort. - This UltraGear OLED display is three times UL-certified—for Anti-Glare, Flicker-Free, and Low Blue Light. Combined with a glossy finish, the display helps reduce distractions, keep your view crisp, and maintain visual comfort—so you can stay focused and perform at your best, even during extended gaming sessions.
- 27” OLED Brilliance with up to 240Hz of Game-Changing Speed - Experience ultra-smooth, tear-free gameplay with up to 240Hz refresh rate on a glossy, bright 27” QHD OLED display.
RTINGS reports very sharp motion and low input lag in certain gaming picture modes. Those findings support the monitor’s competitive-gaming appeal, but they do not mean every game or picture mode will deliver the same result. Check your game settings and graphics performance against the mode you intend to use.
OLED contrast and HDR
RTINGS finds deep blacks, a wide color range, and bright HDR highlights without haloing. It also notes that colors do not get as bright as pure white, and flags HDR overbrightening and VRR flicker. The display’s HDR strengths therefore coexist with image-behavior caveats; they are not a guarantee of perfect HDR presentation in every scene or game. RTINGS records an October 5, 2026 review update that converted the page to Test Bench 2.2 and added a Longevity 3.0 test box; that update should not be read as a fresh validation of every earlier test result. See the RTINGS review.
Rank #2
- 240Hz Refresh Rate - Gear up for smooth gameplay with an ultra-fast 240Hz OLED display. The faster speed lets you respond quickly to opponents and stay a step ahead of the competition. Plus, enjoy smoother scenes with less lag or ghosting thanks to LG UltraGear OLED's nearly instantaneous 0.03ms (GtG) response time.
- VESA DisplayHDR True Black 400 & 1.5M:1 contrast ratio - VESA DisplayHDR True Black 400 certified means this monitor meets industry standards for brightness as well as deep, rich black color expression. With a 1.5M:1 contrast ration, the benefit for gaming impeccable color and image detail in dark scenes for a stunning visual experience.
- NVIDIA G-SYNC Compatible and AMD FreeSync Premium Pro - Officially validated by NVIDIA as G-SYNC Compatible and equipped with AMD FreeSync Premium Pro means this UltraGear provides smooth, fast action that reduces screen tearing and stutter. Never miss a frame of the action as you clinch your victories.
- Anti-Glare / Low Reflection OLED - Play with less distractions thanks to an anti-glare screen that minimizes light reflections and lets you concentrate on winning.
- 2 Year UltraGear OLED Warranty - Game with peace of mind. This UltraGear OLED gaming monitor is protected by a two year limited warranty covering internal and functional parts and labor, including OLED Display Panel. See Warranty Information on this page for all warranty details.
Limitations to consider before buying
Desktop work and static content
RTINGS flags text fringing and possible burn-in from extended static content. Those points matter if the monitor will spend long days showing fixed application panels, spreadsheets, or other unchanging elements as well as games. OLED’s contrast is attractive, but this review does not establish that the monitor is ideal for every static-heavy work routine.
Room lighting and reflections
The matte coating can reduce reflections from smaller light sources, according to RTINGS, but may struggle with intense glare. If your screen faces a bright window or strong lighting, the coating is not a substitute for managing the room’s light. Your viewing environment can change how useful the matte finish feels.
Rank #3
- New firmware update available for improved performance, please review the Troubleshooting Guide below for more information
- 1250 Nits Peak Brightness for Bold HDR Gaming - Powered by UltraGear evo's next-generation Hyper Mini LED technology, the display reaches up to 1250 nits peak brightness and meets VESA DisplayHDR 1000 standards. Bright highlights and strong contrast keep gaming visuals clear and impactful—even in bright indoor environments.
- HDR1000 Delivers Explosive Highlights and Precise Shadow Detail - VESA Certified DisplayHDR 1000 brings games to life with brilliant highlights and deeper shadow detail. Explosions, energy effects, and bright environments appear vivid and sharply defined, while darker scenes maintain texture and clarity. With up to 99% DCI-P3 color, every scene displays rich, impeccable color.
- Hyper Mini LED Powers Ultra-Bright 5K Gaming - UltraGear evo’s Hyper Mini LED powers ultra-bright 5K gaming. With 9,216 LEDs and 1.5× more local dimming zones, GM9 delivers brighter highlights, deeper contrast, and sharper detail. Zero optical distance engineering brings the backlight closer to the panel to reduce light bleed and help minimize blooming.
- 5K Gaming with Uncompromising Detail - Experience incredible detail on a 27-inch 5K (5120×2880) display packed with over 14 million pixels. The ultra-high resolution reveals sharper textures, clearer UI elements, and richer environments—bringing every world, character, and visual effect into stunning focus.
USB-C and setup ergonomics
RTINGS notes that USB-C power delivery is limited to 5W, so do not assume it can meaningfully power a laptop. T3’s reviewer used the display for work and gaming over a couple of weeks and reported vivid OLED color, smooth gaming, and useful ergonomics, but found input switching not always smooth and said the stand pushes the monitor forward from the rear. The same reviewer did not feel a need to use the 720Hz mode in their own play. These are observations from that reviewer’s setup, not universal results. See T3’s review.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Who should buy it?
- Consider it if you are a competitive PC gamer who prioritizes exceptionally high refresh rates, can drive the games you play at high frame rates, and is comfortable with the choice between 1440p/540Hz and 720p/720Hz.
- Think carefully if you want one monitor mainly for long hours of static desktop work, because the review flags text fringing and potential burn-in.
- Look elsewhere or compare closely if 4K resolution, bright-room performance, or a lower purchase price matters more than extreme refresh rates.
RTINGS identifies the ASUS ROG Swift OLED PG27AQWP-W as a close alternative with a glossy coating; its review says the LG’s matte finish handles light better while glossy may look clearer. RTINGS also notes higher DisplayPort bandwidth on the ASUS and USB-C on the LG. Verify current availability and regional specifications before relying on that comparison for a purchase.
Rank #4
- Ascend your game with the speed of UltraGear - Experience next-level QHD gaming performance.
- 180Hz Refresh Rate & 1ms GtG - Gear up for smooth gameplay at up to 180Hz refresh rate and 1ms GtG. The faster speed and smoother action lets you respond quickly to stay a step ahead of the competition.
- 1000R Curved Screen - This UltraGear monitor's dramatic and steep 1000R curve draws you in with game play by extending the periphery to feel like you're surround by the action.
- AMD FreeSync - AMD FreeSync equips gamers with a fluid, virtually tear-free gaming experience. With up to a 180Hz refresh rate at Full HD resolution and low latency gameplay, you'll never miss a frame of the action as you play at peak performance.
- Gamer-Centric Design - Lose yourself in the game with a three-side virtually borderless, ultra-thin design that optimizes space on your battlestation. With two HMDI ports and DisplayPort connectivity on a tilt adjustable display, game to your specs.
Price and availability
LG announced a US preorder price of $999.99 on January 6, 2026. That is historical launch-period pricing, not a current quote. Check local price, stock, and warranty terms before deciding whether the monitor offers good value. The announcement is on the LG US Newsroom.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
