How CNET Tests Monitors
Monitor testing and evaluation consists of formal and subjective quality tests and hands-on assessment of the display’s design and features — connection selection and location, menus and options and overall behavior. As part of the process we use the monitor for tasks specific to its mission, such as everyday productivity, video streaming, image and video editing or different types of gaming (such as FPS or RPG). Note that we only report a fraction of our results, usually what’s necessary to adequately convey a monitor’s strengths and weaknesses for particular uses.
The process begins with unboxing and setup; it’s connected to our Windows-based desktop testbed (or a relatively high-end Mac in cases that require it) equipped with a current-generation Intel Core i9 and high-end Nvidia GeForce graphics card. Both the computer and monitor are plugged directly into a wall outlet to prevent any power issues that might impact performance.Β
We generally prefer to use our cables rather than the manufacturer-supplied ones since they’re a known quantity and tend to be higher quality; if we run into any issues, we double check using the manufacturer’s cables. DisplayPort is our primary connection for testing. If the monitor specifies any console-specific capabilities, we connect it to the relevant console(s), Xbox Series X and/or PS5 via HDMI.
Before any testing begins, we photograph the default settings and all menu options for reference and to determine the complete set of tests we’ll need to run on that particular monitor given its specific capabilities; how extensively we test depends on the capabilities of the monitor, the screen and backlight technology used, and the judgment of the reviewer. We disable power-saving measures where relevant, which can affect brightness and related measures (the option is mandatory per California law). We use a subset of these tests to evaluation laptop displays and run them both plugged into a wall outlet and on battery using the default profile but with screen timeouts disabled.
We also record any relevant information about the panel — manufacturer specs for resolution, color gamut and profiles, refresh rates and so on — that may impact our evaluation against manufacturer’s claims. While we review a display with the company’s publicly expressed target market in mind, we also consider the monitor’s suitability for other uses that might apply. Wherever possible, we download drivers and color profiles specific to the monitor.
What we measure
All measurements are performed using the most recent version ofΒ Portrait Display’s Calman Ultimate software using an X-Rite i1Display Pro Plus (rebranded asΒ Calibrite ColorChecker Display Plus) and a variety of included patch sets, with additional HDR testing using a Murideo Six-G pattern generator and or the Client3 HDR patterns within Calman. We periodically spot check the colorimeter’s accuracy against theΒ Konica Minolta CS-2000 spectroradiometer used for our TV testing.Β
Our test lab is equipped with blackout curtains to fully block ambient light, though complete darkness isn’t essential since the colorimeter sits directly on the screen and isn’t affected by dim lighting. The room has natural light and various artificial sources for normal usage evaluation.Β Β
Color accuracy results are reported in units of Delta E 2000. We perform most of the tests (where we know results vary) at both 100% and default hardware brightness levels.
Core tests — those we run on every display, regardless of intent or price — include:Β
- White point, brightness (peak and minimum), contrast and gamma for sRGB and the native color space measured across 21 gray patches (0-100%), reported rounded down to the nearest 50K as long as there are no big variations. A variation of plus or minus 200K around the target color temperature is considered acceptable for all but the most color-critical displays.
- Color gamut coverage and accuracy for sRGB and the native color space using Calman’s standard Pantone patch set plus grayscale and skin tone patches.
- We addΒ Blur Busters’Β motion testsΒ for gaming monitorsΒ to judge motion artifacts (such as ghosting) or refresh rate-related problems.Β
If a monitor has menu options beyond the basics, we run the same core tests for the following settings when available:
- All color presets
- All gaming presets (such as FPS). We also test brightness for pixel overdrive and motion-blur reduction modes (which tend to lower brightness considerably).
- Gamma for at least 1.8, 2.2 and 2.6Β
- Color temperatures for at least 5000K, 6300K, 6500K and 9300K
For HDR, we add testing for HDR-specific presets (such as Game HDR or Cinema HDR) and brightness for window sizes of 1%, 5%, 10% and 100% of the screen.
Finally, there are tests we only run when needed to understand the measurements we’ve gotten or to confirm that artifacts we’re seeing — notably nonuniformity — aren’t imaginary.Β
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Source: CNET