Lenovo Legion Y25-25 and Samsung Odyssey G4 Review

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According to the manufacturer, the Lenovo Legion Y25-25 should be able to conjure up response times of 1ms on its 240Hz screen. We did not achieve that, but the compact full-HD screen is fast and has a nice display in the most commonly used color space, sRGB. That is also the only supported color space: the screen does not offer many extras. The HDR option is not really useful: the brightness is insufficient for gaming with HDR. If you like the design, you can buy the screen, but remember that there are better screens for less.

Not so long ago, manufacturers proudly announced their first monitors that had a 240Hz panel. We are now about five years later and 240Hz is no longer a feature to make a lot of fuss about in your press releases. For consumers, however, something much more important has changed: the prices of 240Hz screens have roughly halved. That means that you can already buy a 25″ screen with a 240Hz full HD panel for around 250 to 270 euros. Game on!

The two screens we’re looking at here are the Lenovo Legion Y25-25 and the Samsung 25″ Odyssey G4, with the resounding name LS25BG400EUXEN. You can currently buy the Lenovo screen for 270 euros and the G4 will cost you around 260 euros. In both cases, you can buy an IPS screen with a diagonal of 25 inches, of course with the aforementioned 240Hz refresh rate. Both screens support AMD’s FreeSync and are G-Sync compatible so that even if your video card cannot handle 240Hz, the images will be neat The minimum frame rate for the Legion is 44Hz and for the Samsung, it is 48Hz, which makes the variable frame rate range of the screens nice and large.

In terms of their specifications, the screens hardly differ. Their price is also almost the same, so where are the differences? We compare the two fast displays and put them next to screens from other manufacturers with reasonably high refresh rates. We have not yet tested many 240Hz screens, but the Legion and Odyssey show that such screens are becoming increasingly accessible.

The feature set and practice

The two screens are made for gaming and to keep the price relatively modest. Certain concessions have been made for this, but both manufacturers have tried to retain the relevant features. For example, the functionality is somewhat stripped down, because both screens are limited to only the sRGB color space, in addition to a few options to personalize the display and adapt it to gaming.

However, both manufacturers thought the appearance was important. Lenovo opts for round holes as an accent with the Legion. They can be found on the back and the foot is also perforated. Moreover, that foot has a blue bottom, which makes it stand out quite a bit. The rest of the design is quite sleek, with an almost bezel-less design for the top and side edges. The lower edge is wider and houses the Legion logo in the middle and six physical buttons on the right.

The Odyssey has a busier design, with a more angular foot and especially the faux speakers at the bottom left and right that stand out. The back is also quite noticeable thanks to a blue ribbed, flared attachment of the foot on the back. The entire back also has a fairly busy relief. The screen itself is, apart from the bottom edge, also virtually edgeless and the Samsung logo adorns the bottom center.


The Legion and Odyssey both have a foot that gives the screen a lot of freedom of movement. Samsung allows the screen to be adjusted in height: you can adjust the screen by 120mm. The screen can also be turned left and right in portrait mode and you can tilt it forwards and backward, about 3 and 22 degrees respectively. Finally, you can rotate the screen on its base, fifteen degrees to either side. That foot is a rectangular beam with a spread V-shaped, angular foot. In the position towards the screen is a bracket with which you can secure your cables.

Lenovo has assigned the same freedom of movement as Samsung to the Legion. The screen is slightly more height adjustable at 130mm and the tilt function is also marginally more extensive, thanks to a tilt of 5 degrees forward and 22 degrees back. The rotation options to portrait mode are also left and right, with 90 degrees instead of the Samsung’s 92 degrees. You can rotate the screen 30 degrees left and right on the base. The foot, or at least the upright, is tighter and is a round tube. Here too, a simple form of cable management is possible thanks to a fixed ring through which you can feed your cables.


A big difference between the two screens is the way they are powered. Lenovo has a built-in power supply, so you simply have to plug it into the screen. Samsung supplies a small adapter that supplies the screen with direct current.

The Legion Y25 only has one HDMI 2.0 and one DP 1.2 port on board, but it does put a 5Gbps USB hub next to it. Samsung has two HDMI 2.0 ports and a single DP 1.2 port and includes a headphone output. The USB port you see is for service purposes and of no interest to the end user. We already mentioned the faux speakers, but although it seems that the Odyssey has speakers on board, that is only a design element and not functional.

The Legion Y25 has one last feature that the G4 lacks: a bracket to hang your headphones on. You can use the blue tab on the left side of the screen to fold down that metal bracket.


The Samsung Odyssey has a kind of d-pad to operate the screen. It’s at the bottom in the middle, a bit hidden behind the Samsung logo. There is a center button and four buttons all around. You use the middle button as a power button and with the rest you operate the menu. It takes a lot of getting used to using that menu and personally I didn’t find it very pleasant to work with. The buttons on the front of the Lenovo Legion are a bit more traditional in terms of functionality and work a little more pleasantly. This has the disadvantage that the buttons are very visible. Both menus are quite sparse but functional.

With the Legion, there are menus to adjust the most important picture properties and you can adjust the settings for gaming.

The Odyssey has more extensive options, including the possibility to turn on a crosshair yourself. You can also adjust your color channels, for example, and you have more control over the display. The G4 has one more special feature: the Ultrawide Game View. This simulates an ultrawide monitor, so you see more on the sides of your playing field than when you display the standard 16:9 ratio. In addition to an ultrawide 21:9 ratio, you can also choose other different ratios.

Test method and test field

For this review, as usual, we took an extensive series of measurements. We measure brightness, contrast and color rendering using a Spectracal C6 colorimeter, an X-rite i1 Photo Pro 2 spectrophotometer and Portrait Displays Calman Color Calibration software. We test monitors as they come out of the box, adjusting the brightness for color measurements to a value as close as possible to 150cd/m². We measure any sRGB and Adobe RGB modes separately. We do the same for any HDR mode.

We measure response times with a photo sensor and the LeCroy Waverunner 6100 oscilloscope. We ran more extensive response time tests for this article, measuring 20 transitions. We determine the input lag with a Leo Bodnar tester, sending 1080p-60Hz signals to the screen in addition to 1080p-60Hz. To determine viewing angles, we measure residual brightness and color change at a 45-degree angle from a perpendicular measurement. For the uniformity measurement, we look at the ratio between the brightness at fifteen measuring points, measured on a completely white and a completely black screen. We also determine the relative color differences along the edges in relation to the center. Finally, we measure the energy consumption of the monitor,

The test method has recently been adjusted: we have especially adjusted the measurements for color and gray deviations and the way in which we measure them. You can read more about these adjustments in this .plan .

Color space Default view sRGB
Lenovo Legion Samsung Odyssey G4 Lenovo Legion Samsung Odyssey G4
Picture mode Standard Custom sRGB sRGB
White Point (6504K) Normal Normal Normal Normal
gamma 2.2 2.2
Gamma setting 2.2 Mode1 2.2 Mode1

The menu settings of the Lenovo and Samsung when tested in the three color spaces

Test field

We have taken the faster gaming screens with a screen diagonal of 24 to 25 inches as comparison material. We have chosen screens that can handle 165Hz as a refresh rate as the lower limit. The two tested screens are of course 240Hz screens. Half of the tested screens have a VA panel, the other half an IPS panel. In the table below we compare the two tested 240Hz screens. The prices of the screens tested are listed in a second table below.

Monitor Panel type Refresh Actual price
Lenovo Legion Y25-25 ips, 1080p 240Hz € 269,-
Samsung Odyssey G4 25″ ips, 1080p 240Hz € 249,-
AOC 24G2SU/BK VA, 1080p 165Hz €179
AOC C24G2U/BK VA, 1080p 165Hz €192.01
IIyama G-Master GB2470HSU-B1 ips, 1080p 165Hz €182.01
IIyama G-Master GB2570HSU-B1 ips, 1080p 165Hz € 199,-
Iiyama G-Master Red Eagle G2466HSU-B1 VA, 1080p 165Hz €162.64
ViewSonic VX2718-P-MHD VA, 1080p 165Hz €187.70
Fashion model Lenovo Legion Y25-25 Samsung Odyssey G4 25″
Screen diagonal 24.5″ 25″
Curved screen no no
Resolution 1920×1080 (full hd) 1920×1080 (full hd)
aspect ratio 16:9 16:9
Pixel density 90ppi 88ppi
Panel and backlight
Type of panel lcd lcd
LCD panel Ips Ips
Response time 1ms 1ms
Refresh rate 240Hz 240Hz
G sync support G-Sync Compatible
FreeSync support FreeSync Premium FreeSync Premium
FreeSync max refresh rate 240Hz
Imaging technique
Viewing angle 178° 178°
Brightness 400cd/m² 400cd/m²
Contrast ratio (static) 1,000:1 1,000:1
Color depth 8-bit (16.7 million)
Video in Display Port, HDMI Display Port, 2x HDMI
Total video inputs 2x 3x
Outputs (Monitors) 3.5mm
USB hub (downstream) USB 2.0
Ergonomics 90° horizontally rotatable (Pivot), Height adjustable Rotatable on foot, Height adjustable, Vertically tiltable
Power consumption 30W 18W
Bracket mounting Vesa 100mm Vesa 100mm
Included accessories/cables Display Port, USB HDMI
Height 512.5mm 552.9mm
Adjustable height 120mm
Minimum height 432.9mm
Height (without foot) 341.1mm
Width 558.7mm 558.5mm
Depth 250.5mm 244.8mm
Depth (without foot) 85.4mm
Weight and color
Weight 5.59kg 4.5kg
Weight (without stand) 2.8kg
Colour Black Black

Response time and input lag

You obviously buy a 240Hz screen primarily for gaming, so you can benefit from the high refresh rate and hopefully fast transitions. Both Lenovo and Samsung promise 1ms for gray-to-gray transitions in the fastest overdrive mode, which is undoubtedly a best-case scenario. For a 240Hz display, transitions should take no longer than 4.16ms to fit within a single frame.

We first measure the response times with the overdrive switched off, then we set the overdrive to the maximum position and finally we see in which position the response times are optimal. That is, at which overdrive position are the response times short, but also the under and overshoot limited. After all, with overdrive the pixels are controlled with higher voltages to change the light transmittance of the LCD as quickly as possible, but that often means that the crystals rotate a little too far and therefore block either too much or too little light. This phenomenon is called over- and undershoot and can lead to disturbing artifacts.

According to Samsung’s specifications, the Odyssey G4 should be able to achieve response times of 1ms for gray-to-gray transitions, and Lenovo also advertises response times of 3ms or 1ms in Extreme overdrive mode. In both cases, we do not see that 1ms in the standard transitions, although the G4 only takes 1.6ms for the transition from light to dark gray. That requires the overdrive on the most aggressive setting, resulting in considerable overshoot. That is much less the case with the Lenovo: the overdrive seems to have hardly any influence on the control of the pixels.

Extensive response time test

Because response times for gaming screens like this are extra important, we also performed our extensive response time measurements in addition to the limited measurements. We measure the response times and overshoots of twenty transitions. We measured the Legion in the optimal (Fast) and fastest (Extreme) overdrive mode at 240Hz. With the Odyssey, only the optimal overdrive position, ‘Faster’ in this case, has been measured.

The Legion only achieves response times of less than 4ms for transitions to and from black or white: the gray-to-gray transitions require more time. The response times can be faster if you set the overdrive to maximum, as shown in the second diagram, but then the overshoot for certain transitions is very high. With the Odyssey, the gray-to-gray transitions are faster, but all transitions remain well below the 4.2ms that a frame at 240Hz takes.

Input lag

Actually, just like the transitions, a 240Hz screen should have an input lag of no more than 4.2ms. However, we test with the Leo Bodnar meter at 60Hz as standard, for which 16.6ms is already enough. However, we measure just under nine milliseconds for both screens, which is about enough for a 120Hz screen. Now there’s no screen that has such a low input lag to keep up with a 240Hz refresh rate, so we won’t overcharge the Legion and G4 for that.

Default display: brightness, contrast and color

We tested the screen with almost no adjustments right out of the box, with only the brightness adjusted to 150cd/m². Because we do not adjust anything else to optimize the performance of the screen, the screen is emphatically not set to its best position. Logically, this does not produce the best results in the graphs below: only the ‘out-of-the-box’ performance. Keep that in mind when viewing the results.

The minimum brightness of the two 240Hz panels is almost equal and still quite bright, especially in a dark room after a night of gaming. However , compared to the other screens, that brightness of roughly 75cd/m2 is not very bad. In terms of maximum brightness, the Odyssey G4 takes a clear lead: the backlight pushes the brightness towards 500cd/m 2 , considerably higher than the other screens tested. In terms of contrast, the two fast screens score almost equal again and quite good for IPS panels, although Iiyama shows that an IPS panel can also achieve quite a higher, and ironically also a significantly lower, contrast.

In their standard display, both monitors display a color range that most closely matches the sRGB color space. The degree of coverage is slightly better with the Lenovo than with the Samsung. The latter is also set quite warm, with a color temperature of just above 6000K. With the Lenovo screen, it comes closer to the desired 6504K. The range is also not so different, but here too the Legion is a bit neater.

For all screens, with the exception of the ViewSonic, the color reproduction could be a bit tighter, but the Legion certainly manages to impress with its small gray deviation. The Samsung does well, especially when we look at the overall picture of the color checker, but Lenovo does a little better.

For the sake of completeness, we present the measurement results in the old ΔE 2000 values. So you see that both screens actually have a barely perceptible deviation: everything below the three is normally not visible.

Display sRGB

From now on we will measure all screens in the sRGB color space; the gamut for which the most content is created. In their standard view, the display was already very similar to the sRGB mode and the results are therefore not very significantly different from the standard mode. In fact, while the Samsung Odyssey does have a mode that is actually called sRGB, we have to leave the settings for the Legion on ‘Standard’ to get the best sRGB display. There is an sRGB mode, but it produces higher deviations than the standard mode.

The AOC screens do not show up neatly at the desired brightness of 150cd/ m2setting, but fortunately the other screens do. While the Legion has better sRGB coverage and color temperature than the Odyssey G4, the color deviation is less than that Samsung. The grayscale deviation of the Legio Y25 has increased considerably compared to the standard display, while the display mode remains unchanged at ‘Standard’. This is because we also use the sRGB gamut as a target for the sRGB measurements, which deviates from the 2.2 gamut curve that we use in the standard display tests, especially in darker tones. This is more apparent in the ΔE ITP measurements than in the ΔE 2000 values, because the former weighs more heavily on brightness deviations. The graphical representation clearly shows that the grayscale deviations for dark shades differ much more with the ΔE ITP calculations than with the ΔE 2000 calculations.

Other display modes

The Lenovo Legion Y25-25 only has the option to turn sRGB on or off. Other color spaces are not supported. You can turn on game modes: there are two fps modes FPS1 and FPS2, Racing, and RTS, and a self-adjustable game mode Game1.

The same goes for the Odyssey G4: there is an option to turn sRGB on and off, but other color spaces such as DCI-P3 or AdobeRGB are not supported. You can, however, turn on various modes, which are mainly aimed at gaming, such as FPS, RTS, RPG and Sports . There is also a Cinema mode and a DynamicContrast mode.

HDR view

The Samsung Odyssey does HDR without grumbling, but we can’t say that about the Lenovo Legion. By manually switching the screen to HDR display, we were still able to perform the HDR measurements, but this was not done automatically. The Legion also doesn’t have HDR certification, because as you can see below, we don’t even reach the 400cd/m2 required for HDR400 certificationIn other words: you can force it through the menu, but in practice you don’t have to expect anything from it.

Both screens do not vary their brightness according to whether a smaller part of the screen needs to be brightly lit: that is reserved for screens that display better HDR.

Both screens show considerable deviations in both the color reproduction and grayscale of HDR content, which is particularly striking that the Lenovo Legion lacks brightness. The deviations with luminance are greater than without, while we generally see the opposite. Apart from that, the HDR display of both screens is not at all impressive, not only because of the deviations but of course mainly because they hardly produce any light and have a low contrast.

Uniformity and viewing angles

Samsung sometimes has its viewing angles slightly better than each other, but they do not differ much. The horizontal angles are not particularly impressive, while vertically little clarity remains. Compared to the other screens in the test, it is still fine, but it is not great. Of course, that is not really necessary, because with a relatively small screen, which you as a gamer usually just sit right in front of, the viewing angles do not have to be significantly large. Moreover, IPS screens are never as impressive as OLED screens and we don’t expect miracles for this money.

Even if we look at the color reproduction at oblique angles, the 240Hz screens do not impress. The color errors quickly become very large, especially if you look from below or above, so it is important to set the height of your screen properly. Fortunately, both monitors are equipped with a height-adjustable foot, so that should not be a problem.


The screens are relatively small, but even then you prefer to look at a uniform screen, with few brightness differences caused by the backlight or other factors. We measure the ratio between the highest and lowest brightness of black and white areas with an all-white and all-black screen and calculate the ratio of the highest and lowest brightness for white and black. A figure approaching 100 percent is completely uniform and shows little difference in brightness. We also perform this calculation for the highest versus average brightness of the black and white areas. Here too, a nice uniform screen allows the ratio to approach close to 100 percent.

Both the Lenovo Legion and the Samsung Odyssey G4 have significant differences in brightness, resulting in a fairly low uniformity ratio between highest and lowest brightness. That is a bit shrouded when we look at the average brightness versus highest brightness, but the Legion ranges from 131 to 152cd/m 2 , with the top edge in particular a bit darker than the bottom. The Samsung screen makes things even crazier, ranging from 128 to 150cd/m 2, with the center of the screen especially brighter, with darker edges.

Finally, we took a picture of the screen showing a black image so that we can visualize the uniformity in black rendering and also see where the backlight may be leaking some light around the edges. The photo was taken and edited to exaggerate the effect.

As was already visible in the uniformity matrix for black reproduction, both screens do not suffer much from hotspots or backlight bleeding. There are no crazy light leaks to be seen in the photos.

Power Consumption

We measure the power consumption in two scenarios. First we measure the energy consumption while displaying a white screen with a brightness of 150cd/m². That is the brightness we use for normal use and with which we perform almost all our screen measurements.

Under normal conditions of use, the screens require relatively more energy than the other monitors: only the Red Eagle from Iiyama is in between the Legion and G4. At maximum brightness, however, both 240Hz screens are mid-range again. If you use these screens five days a week, eight hours a day at 150cd/m 2 , they use about 33kWh for the Legion and almost 38kWh in the case of the Odyssey G4.


The range of fast screens has increased considerably recently, but it is still difficult to find many screens of about 25 inches under three hundred euros. Larger screens of 27″ with a refresh rate of 240Hz or higher are more available than smaller ones, but you then sacrifice pixel density. With a 24-25″ screen you have more than 88 to 93ppi, but with 27″ screens that drops to 82ppi. Two of those smaller screens with a higher pixel density are the Lenovo Legion Y25-25 and Samsung Odyssey G4 25″. Moreover, they are both screens of more than three hundred euros, of which we have thirteen in the Pricewatch at the time of writing.

The Legion is a bit simpler than the Oddysey, with a fairly useless HDR display but a very usable sRGB display, the most commonly used color space for Windows users and gamers. The Odyssey has a slightly better display and has something that comes close to HDR reproduction, but still not convincing in that area. Both screens do not excel in uniformity and viewing angles, but their main feature is of course the high refresh rate.

Both screens reach 240Hz and do that quite nicely. The response times of the Legion, unfortunately, don’t come close to the promised 1ms, but the Odyssey has one transition that does: that’s probably reason enough for the marketing department to advertise with it. Please note that the other transitions take a lot longer, but all our measurements remain well below the 4.2ms limit; that is how long a single frame is displayed.

This makes the Odyssey G4 a lot more attractive than the Legion. The screen has more settings options, better display properties and has much better response times than the Lenovo Legion. On top of that, the Samsung is even cheaper. As far as we’re concerned, the Samsung Odyssey G4 in 25 inches is the clear winner and highly recommended if you’re looking for a fairly modest, but very fast screen. If you’re satisfied with lower refresh rates, or your video card doesn’t have the muscles, you can also spend less money for a 165Hz screen of the same size. And if you still have enough space on your desk, you can always opt for a slightly larger 27″ screen with 240Hz: that costs just as much, even if you sacrifice something on your pixel density.

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