The Iiyama G-Master GB2590HSU-B1 monitor chooses a very classic design with well-treated matte black plastic. Only the Y-foot is a little more original than the rectangular foot on the other screens from the Japanese brand, and lets you see the page game of this screen.
The Y-foot is quite wide (50 cm for a depth of 25.6 cm). Fortunately, its branches are quite thin and free up a lot of space on the desk.
This screen offers height adjustment over 13 cm and inclination between -3 ° and + 18 °. The G-Master GB2590HSU-B1 also has a swivel joint to switch to portrait mode.
The back of the chassis is all of good quality, grainy matte black plastic. The connector is oriented downwards. The monitor is compatible with VESA 100 x 100 mm mounts when the stand is removed. There is also a fairly basic cable walkthrough at the bottom of the arm so that all the wires can be grouped together.
The connection consists of an HDMI input, a DisplayPort input, a headphone output and USB 3.0 ports. The screen also has two 2 W speakers, far from being exceptional, but which help even for system sounds and for watching short videos.
Navigation through the OSD (On-Screen Display) menus is performed using five buttons located on the edge of the screen. Not very practical, they generate quite frequent handling errors. Too bad the manufacturer did not choose a joystick as it does on some of its models (e.g. Iiyama ProLite XB3288UHSU-B1).
On our 140 x 60 cm desk, the Iiyama GB2590HSU-B1 is very comfortable. The base is not very compact, as the screen with a depth of 25.6 cm fills a good part of the desk. However, its ventilated side leaves enough space to install the keyboard and mouse. The Full HD definition of 1920 x 1080 pixels on this 25-inch panel results in a very average resolution of 88 pixels per inch (ppi). The full HD resolution of 1920 x 1080 pixels is excellent for gaming, especially at 240 Hz – a frequency that already requires a powerful graphics card. For other tasks, such as office automation or even web browsing, this definition is still quite limited.
Colors and contrast
Right out of the box, the Iiyama G-Master GB2590HSU-B1 monitor is already very well calibrated. With an average Delta E of 2.4, the colors can be considered faithful to those sent by the source, while the gray levels are perfectly reproduced thanks to an average gamma measured at 2.2 and a perfectly stable curve across the spectrum. Same observation on the side of the color temperature, whose average is measured at 6380 K, very close to the reference value (6500 K), while showing perfect stability over the whole spectrum. By lowering the brightness to 20 to achieve a white close to 150 cd / m², the image quality remains almost unchanged, with a gamma dropping very slightly to 2.1, with no real effect on the reproduction of grayscale. Calibration of the screen using a probe makes it possible to display perfect colors, especially at the level of red, green, blue and yellow, which fall below a Delta E of 2. Gamma curves and temperature are perfectly stabilized. You can download the color profile by clicking this link.
The original 1170: 1 contrast is slightly lower than that measured on the Asus TUF Gaming VG27AQ and AOC 27G2U, in both cases higher than 1200: 1. This contrast remains very good for an IPS panel. In any case, this monitor remains far from the contrast raised on the best VA monitors on the market, such as MSI Optix MAG271CR or Philips BDM4037UW, whose contrast ratio exceeds 4000: 1. In practice, this translates to washed-out blacks in a darkened room. During the day, this is much less noticeable.
The average white homogeneity deviation is good. We measured it at only 8% on the 25-inch panel. Thus, there is no difference in brightness that can be felt before the eye. We did not notice any light leaks around the corners or anything ambiguity (“cloud effect”) on our test model. IPS technology also offers good viewing angles, with very little variation when the user is no longer in front of the screen.
Iiyama G-Master GB2590HSU-B1 does not use pulse width modulation (PWM, Pulse width modulation) to adjust the brightness; it is therefore devoid of flicker and does not cause headaches for those who are sensitive to this phenomenon. Iiyama also offers a blue light reduction mode in software via OSD.
This monitor handles FreeSync (and by extension G-Sync) between 40 and 240 Hz and therefore works best when the graphics card transmits between 40 and 240 frames per second. To get the most out of this screen, you need a pretty powerful graphics card, especially to be able to display 240 frames per second in Full HD. A graphics card like the GeForce RTX 3060 or Radeon RX 6600XT seems like a minimum. You can even choose higher performance models for the most demanding games. In all cases, the fluidity is there and the image does not suffer from tear problems (tear) or jerk (microarray).
We measured the afterglow time to 7 ms with overdrive (in French “response time” in the OSD) set to 4. With the maximum setting of 5 we notice a small effect of reverse ghost. The Iiyama G-Master is not one of the most responsive monitors on the market, as the Samsung Odyssey G7 27-inch and G9 49-inch equipped with a 240 Hz VA panel have an afterglow time of 4.5 ms, but its IPS- panel offers wider angles. However, with its 27-inch Full HD IPS 280 Hz panel, the Asus VG279QM also performs better with an afterglow time of only 4.5 ms. The display delay measured at 11.6 ms (at 60 Hz) results in an almost zero delay between the action performed with the mouse or keyboard and its effect on the screen.