LG 27GN750 Evaluation: 240Hz Refresh, “1ms” IPS

Those of you who follow our monitor reviews may know the LG 27GL850, LG's first 1ms class IPS gaming display, and our currently most popular 1440p gaming monitor overall. In our test, we found that although this panel with usable overdrive settings could not achieve a gray to gray average of 1 ms, it still had the fastest 1440p IPS display on the LG thanks to improvements in LG's IPS LCD technology Market and a great buy was for gamers.

The LG 27GN750 that we are testing today is a very convincing product. It uses the same 1 ms class IPS technology, but brings it to a new panel type. Instead of using 1440p at 144 Hz, the 27GN750 offers a response time of 1 ms for a 27-inch 1080p 240Hz panel. This gives us another option in the high-end market for 1080p monitors that could be a really convincing purchase thanks to IPS.

However, it's not the first 1080p 240Hz IPS monitor we've tested. This goes to the MSI MAG251RX, which has a smaller 24-inch design and uses a panel from AU Optronics. And to be honest, it works very well and offers fast enough response times to keep up with the refresh rate of 240 Hz. LG has set itself the task of offering a great super high refresh experience with the well-known high-quality IPS technology.

Aside from the key specs we've talked about, LG offers a fairly typical experience: G-Sync compatibility and adaptive sync, so this monitor works with both AMD and Nvidia GPUs. LG also promotes HDR10 support, but without VESA DisplayHDR certification, it means it's a worthless shot. This is mainly because it's only an sRGB display, 99% according to the LG website, but unlike the 27GL850, it doesn't offer a lot of bandwidth.

The LG 27GN750 also only costs $ 400, which is typical of LG's current range of monitors. This makes it cheaper than the ViewSonic XG270 and Acer XV273X and at about the same price as Asus' attractive VG279QM, which we hope to test soon.

When it comes to design, LG sticks to the proven formula used in the UltraGear line in recent years. We like it from a visual standpoint, it's not the highest quality construction because what you get is mostly plastic, but the sleek black aesthetic with a few red highlights looks good. Nothing crazy is going on here, the focus is exclusively on the IPS display with decently slim bezels.

There are some nifty features, including height, tilt, and pan support, as well as very easily accessible ports on the back. LG does not stow them behind a plastic flap or along the bottom, they are located directly on the back and are easily accessible. Here two HDMI and a DisplayPort as well as a USB hub and an audio output. No speakers are installed.

The only real problem is the stand, which we found a little shaky for our taste, nothing outrageous, but the connection between the pillar and the legs is not great, so it has the ability to rock around easily.

As with most UltraGear monitors, the screen display is controlled by a direction switch at the bottom of the screen. We like the OSD layout from LG, it is easy to navigate and offers all relevant information at a glance.

Opinion: 240Hz vs 144Hz

One question that comes up when reviewing such high-update monitors is: Do you really need 240 Hz and is it an upgrade above 144 Hz? After reviewing some 240 Hz monitors recently, we are getting more and more used to the improvements in clarity and motion handling that 240 Hz offers over 144 Hz. So we would say that there is definitely an improvement. Not as much as boosting from 60 Hz to 144 Hz, but playing games on a 240 Hz display like this feels extremely responsive, and you could even say that for desktop applications.

In most cases, you still need a powerful PC to achieve more than 200 FPS at 1080p in many titles. So make sure you have a fast CPU to avoid CPU bottlenecks and get the most out of this type of monitor.

Another thing that should be considered is the pixel density of this monitor. 27-inch screen area, but only 1080p resolution is not the highest resolution or sharpest experience there is, and we think 27-inch is a bit too big for a 1080p monitor. It's not bad for games, especially when the refresh rate is so high, but for general desktop use like surfing the web, we consider pixel density and resolution to be a limitation.


Now let's look at all the important information about response time, starting with the four main overdrive modes. At 240 Hz, the off mode for this IPS panel shows quite good inventory response times with a gray to gray average of 6.1 ms. This is faster than many IPS panels with overdrive. So we got off to a good start.

Response times / overdrive modes

LG 27GN750 – Overdrive Off (240 Hz)

LG 27GN750 – Overdrive Normal (240 Hz)

The normal mode manages to improve the performance quite well compared to the off mode without the overshoot noticeably increasing. A gray to gray average of 4.42 ms is good, so 82% of the transitions are within a reasonable tolerance of the update window. I think a lot of people will be happy with this mode, but we can do better.

LG 27GN750 – Overdrive Fast (240 Hz)

In the fast mode, we achieve a slight improvement compared to a gray-gray average of 3.79 ms, without significant exceedances occurring. So this is the best mode for 240 Hz games with high update. With 95% of the transitions corresponding to the refresh rate of 240 Hz, an IPS monitor is left that is really able to update with 240 Hz and a resolution of 1080p.

LG 27GN750 – Overdrive faster (240 Hz)

Like most of LG's latest 1 ms monitors, they essentially cheat to list this as a 1 ms monitor. With the faster overdrive mode I was able to achieve a gray-gray average of 1.9 ms. For some transitions below 1 ms, the overshoot level here is very high, with an average error of 38% and 55% of the transitions that have severe inverse ghosting. Although this mode is approximately 1 ms long, it is unusable due to the bright traces it creates in practice.

We now know that Quick Mode is the best way to get maximum performance at the highest allowable refresh rate. Which mode is best for the entire refresh rate range? After all, it is an adaptive synchronization monitor, so that the refresh rate fluctuates in games and can be in different areas depending on the game. Consistent good performance across the entire refresh rate range is important to take this into account.

Scrolling through the quick mode shows that an overshoot is visible at 144 Hz. At this stage, this is not terrible. However, if this update reaches a gray to gray average of 3.78 ms, a little overshoot creeps in. The monitor is still working well at 120 Hz. But it is at 100 Hz where we see noticeable inverse ghosting. The performance remains fairly constant in Fast mode with an average response time of just under 4 ms, but 120 Hz is around the usable limit for this mode. Underneath, for example at 85 Hz and 60 Hz, inverse ghosting can be seen, so I would not recommend this mode for lower refresh rates.

However, normal mode works very well across the entire update area. Even at 240 Hz, we still get a gray to gray average of 4.4 ms, which is only 17% slower than the fast mode. In normal mode, however, overshoot is only noticeable at 85 Hz and not at 144 Hz, and even at 60 Hz, inverse ghosting is not a big problem. In the meantime, the response times are mostly between 4.0 and 4.5 ms, which is great for an IPS display.

This leads me to two main recommendations for playing with the 27GN750: If you mainly play with high refresh rates, over 144 Hz for competition shooters and the like, I would use the Fast Overdrive mode. If you want to play at lower update rates or if you want a single mode that best covers the entire adaptive sync range, I'll stick to Normal.

How can the 27GN750 be combined with other 1080p and high refresh panels? The new fast IPS range from LG holds up well with a view to top performance, i.e. the best overdrive mode for the highest refresh rate. It's faster than a TN monitor like the Pixio PX5 and easily outperforms the 27GL850. However, it does not offer the same performance as the current generation of TN panels of the 0.5 ms class that you get in the Aorus KD25F from Gigabyte. Here the KD25F is about 20% faster with the same excellent overshoot handling.

One of the bigger fights is between the 27GN750 and the MSI MAG251RX, the two 240 Hz IPS monitors I tested, one with a LG 27-inch panel and the other with a 24-inch AUO. With this chart of peak performance, there is no clear winner. The MSI monitor is 18% faster, but has a higher level of inverse ghosting.

When I look at these two monitors across the refresh rate range, it is interesting to note that the IPS panel from LG is only slightly faster than that from AU Optronics. If you look at the normal mode with the LG monitor compared to Fast with the MSI monitor, the 27GN750 only gets 5% faster at these medium refresh rates and offers slightly better overshoot handling. However, it is superior at higher and lower refresh rates, so the 27GN750 is a little faster when comparing these two modes.

LG has the small advantage that its faster overdrive mode, in this case Fast, is better than the MSI mode called Faster. In this mode, as we have already seen, MSI reaches 3.2 ms at 240 Hz, but is completely unusable at 144 Hz. The LG equivalent is somewhat slower at 240 Hz, but can be used up to 120 Hz without any problems. In my opinion, this makes the LG option more suitable for games with a higher refresh rate, while using adaptive synchronization. Overall, AU Optronics offers a good IPS panel for 240 Hz, but LG's technology seems a bit superior.

Back to the general comparison tables. Performance in the dark is not a problem with the 27GN750. MSI offers a little better in this region, but there is no smudging in the dark. We also see excellent response time compliance for the maximum refresh rate of over 90%. So don't worry that IPS is not good enough for 240 Hz. This latest generation is definitely good enough.

Average error rates are kept well under control even in Fast mode at 240 Hz, and as mentioned earlier, this is an area where the MSI MAG251RX has suffered somewhat. However, the MSI monitor is faster at 60 Hz, although you think that 60 Hz is not used very often with such a high display.

Input latency is not a problem with the 27GN750, with a processing delay less than 0.5 ms and a total chain delay around the 6 ms mark. This is a very responsive display that feels fast in every way. It offers only one of these great combinations of low input delay, high refresh rate and good response times.

The power consumption is average, nothing interesting to highlight. This is your standard 27-inch display in terms of energy efficiency.

A key feature that LG does not offer with the 27GN750 is the stroboscopy of the backlight to reduce blurring. It is therefore similar to the 27GL850 in this regard. MSI's MAG251RX and other options available on the market, such as the Asus VG279QM, include backlight strobe. For those who want this feature, LG's option may not be the best.

Color performance

Nothing special is going on here, since it is a pure sRGB display that does not support a wide color range. Although it is advertised as HDR10 capable, it is not really HDR either. So don't expect real HDR functionality. Still, a 99% sRGB IPS display can still look fantastic. So let's see what we work with …

Standard color performance

This is the performance of the 27GN750 in relation to the default setting. Note that we are switching to a new DeltaE formula for this test and all future reviews, dE ITP instead of dE 2000, since dEITP is the new industry standard. We'll also display dE2000 results so you can compare it to other reviews, but dEITP is a more sensitive and, in a way, better metric. The formula was specially developed to better handle modern displays such as those with a wide range of colors. The basics, however, remain the same: a difference of 1 deltaE should be perceptible to the human eye, and anything below a dE of 2-3 is generally considered accurately.

Our device had a slight shade of pink, but nothing unusual. The CCT average curve is pretty good, but there are some low gamma problems, as you can see in the gamma curve. This leads to a high DeltaE performance in these upper midtones. Therefore, it is not a particularly accurate display for grayscale.

OSD optimized performance

With a wrong white point, these errors such as color saturation continue in our color tests. A dE of 9.35 is pretty high using the new ITP metric, but even with the old formula, we're still looking for performance that isn't entirely accurate. We ended up with an average performance for a gaming display. There is not much new in the ColorChecker test either. These are average results.

There are two main performance issues, and we can fix one of them in the OSD. This is the white dot with some improvements that you can see here. However, the problems with the gamma curve that we saw earlier cannot be solved. So if we look at the grayscale performance, we still get a DeltaE over 3.0. Not a terrible result and more accurate than before, but not perfect. Similar story during color tests, improved performance, but not enough to make this an accurate display.

Calibrated color performance

However, it is possible to achieve a reasonable level of accuracy through a full calibration that we did with DisplayCAL. The gamma curve is now largely resolved, resulting in a DeltaE of 2.05, which is very solid and only disappointed by the dark performance. In terms of saturation, we have a DeltaE below 2.0 and an average of 2.27 DeltaE in ColorChecker, which is a great result for a gaming monitor. Like many IPS displays, the 27GN750 responds well to calibration, and you may get a really good looking monitor.

The maximum brightness after calibration is an average of 350 nits, which is fine for most viewing conditions. As for contrast … well, this is an area that LG's 1 ms class IPS panels are struggling with. The 27GL850 is a particularly bad result. The 27GN750 isn't quite as bad as the 27GL850, but with a contrast ratio below 900: 1, black levels and contrast are still a weakness for this type of panel. In particular, in the MAG251RX you can see the AU Optronics equivalent at the top of the diagrams, which produces a 40% higher contrast ratio, which is more like what we would normally expect from a modern IPS.

The viewing angles are very solid. So if you switch between this and a 240 Hz TN panel, you can generally expect similar contrast ratios but better viewing angles with the LG IPS option. The uniformity was also excellent for my test model, well above average, although IPS monitors tend to be strong in this area.

For whom is that?

All in all, we think the LG 27GN750 is a pretty good monitor. We do have reservations for 1080p monitors that are 27 inches in size, but if you are looking for them, LG offers you excellent performance in combination with generally solid colors. I am very happy that the current IPS technology enables such a combination of extremely high refresh rates and a great viewing experience. A 240 Hz IPS display wouldn't have been a good experience a few years ago, but now it's definitely a reality.

The LG 27GN750 offers performance that is only one step behind the currently best TNs on the market and easily delivers an average response time of 4 ms. This particular model can achieve these speeds across the entire refresh area. You can even push it faster than at the top, which provides a clear and responsive 240 Hz experience.

Given that the 27GN750 also offers a decent color experience, especially when calibrated, along with fantastic viewing angles and uniformity, I would much rather buy this type of 240 Hz display than a TN equivalent, even if the TN 20 % faster ends. Personally, I think a compromise between low speeds is worth it if you gain a lot in the color department, especially if the current pricing doesn't make the IPS version more expensive.

This test in particular produced some interesting results. For one thing, the LG 1ms class IPS panel is faster than a similar offering from AU Optronics, but not much faster. In practice, you will have a fairly similar experience, whether you choose the 27GN750 or high quality AU Optronics alternative like the MSI MAG251RX. LG doesn't have as much of an advantage in this 1080p 240Hz market as in the 1440p market with its flagship panel.

The performance is undoubtedly very strong and offers us the best response times. However, this has led to some compromises. Once again we have inconspicuous contrast ratios, so the 27GN750 is not particularly suitable for players who play in dark rooms. LG also failed to provide backlighting. Both concerns may make an alternative with the AUO panel a better choice.

The LG 27GN750 brings you back $ 400, which is comparable to similar models. It is hard to say definitely whether you should buy this or something else. It really depends on what you're looking for on a monitor. To get the best performance, purchase the 27GN750. If you want backlighting or need better contrast, or aren't a fan of this size, there are a few other decent options available to you. We would personally turn to the MSI MAG251RX as it is a little cheaper and has backlighting. However, this recommendation may not be suitable for everyone.

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