LG UltraFine LG 39.7" UltraFine 5K2K Curved Ultrawide Monitor Review

The LG UltraFine 40U990A is a premium 39.7-inch ultrawide monitor with a sharp 5K2K resolution and a 120Hz refresh rate. It delivers excellent color for creative work and features future-proof Thunderbolt 5 connectivity. It's a great fit for power users who need massive screen real estate, but its high price and demanding hardware requirements mean it's not for everyone.

If you're a creative pro or a power user hunting for a massive, high-resolution ultrawide monitor, the LG UltraFine 40U990A is a serious contender. This 39.7-inch curved beast delivers a 5K2K resolution (that's 5120 x 2160), which gives you a ton of horizontal real estate for timelines, spreadsheets, or multiple windows. It's a premium monitor, sitting in the $1,700 to $1,800 range, and it's packed with features like Thunderbolt 5 connectivity and a 120Hz refresh rate that make it more than just a pretty screen. People searching for a '5K2K ultrawide monitor' or a 'Thunderbolt 5 monitor' will find exactly what they're looking for here, though you'll need a powerful PC or Mac to drive all those pixels smoothly.

The performance story here is about clarity and smoothness, not just raw speed. That 5120 x 2160 resolution at 120Hz is a demanding combo, landing in the 59th percentile for performance in our database. In practice, that means you'll need a modern graphics card to push high frame rates in games, but for everything else, the experience is fantastic. The 5ms response time and FreeSync Premium support mean motion looks clean, whether you're scrolling through a long document or watching a panning video shot. The 450 nits of brightness and 99% DCI-P3 color coverage (97th percentile) are the real stars, making HDR content pop and ensuring your creative work looks accurate.

At around $1,800, the LG UltraFine 40U990A is a significant investment. You're paying for that unique 5K2K resolution, professional-grade color, and the latest Thunderbolt 5 port. If your workflow absolutely needs that extra horizontal pixel count over a standard 4K ultrawide, and you value having a single-cable solution for your laptop, the price can be justified. However, if you're just after a big, high-refresh-rate screen for gaming or general productivity, there are more affordable 4K ultrawides and even OLED options that might offer better pure performance for the money.

This monitor sits in a niche between professional workhorses and high-end gaming displays. Compared to the Dell UltraSharp 27" 4K, you're getting a much larger, curved screen with a higher refresh rate, but the Dell might have better color calibration out of the box for strict color work. Against gaming beasts like the ASUS ROG Swift 32" QD-OLED or the Samsung Odyssey Neo G9, the LG can't match their perfect blacks or insane contrast for HDR games and movies. What the LG offers is a unique blend: more desktop space than a 4K monitor, better motion clarity than a standard 60Hz professional screen, and that cutting-edge Thunderbolt 5 port that neither of those gaming monitors have.

Skip this monitor if you're on a tight budget, if your desk is shallow, or if you're a hardcore competitive gamer. The price is steep, and the size is imposing. If you mostly play fast-paced shooters, a dedicated high-refresh-rate 1440p or 4K gaming monitor like the ASUS ROG Swift will serve you better. Also, if you don't have a modern PC or Mac with a powerful GPU, you'll struggle to run this monitor at its full potential, making it a poor value.

So, should you buy the LG UltraFine 40U990A? If you're a video editor, data analyst, or developer who lives with multiple windows open and craves every pixel of horizontal space, and you want the convenience of a single Thunderbolt 5 cable to power and connect your laptop, this monitor is a fantastic, albeit expensive, solution. It's a productivity powerhouse first. But if your primary goal is competitive gaming or watching movies with the best possible contrast, you'd be better served by a dedicated QD-OLED or Mini-LED gaming monitor. This is a specialist's tool, and it excels in that role.