AOC AG251FZ 240Hz FreeSync Monitor Review

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Brightness & Contrast

To read about our monitor tests in depth, please check out Display Testing Explained: How We Test Monitors and TVs.Brightness and Contrast testing are covered on page two.

Uncalibrated – Maximum Backlight Level

Normally, we try to group monitors by price, size, or technology. Today, it’s all about speed. We found the fastest screens in our database and picked the most recent models for the comparison. Asus is represented by its PG258Q. Acer delivers the XB252Q and Z301C. A second AOC is here in the form of the AG271QG. Finally, we have Dell’s S2417G. All operate at high refresh rates and offer the shortest possible panel response and extremely low input lag.

Gaming monitors need to be bright enough to accommodate blur-reduction technology with its output-robbing backlight strobe. The AG251FZ omits that feature but delivers a high white level anyway, nearly 400cd/m2. Few players will need that much light, but if AOC were to add blur-reduction in the future, the panel is ready.

TN and IPS screens are about even in the black level and contrast department. We always hope to see at least 1000:1, and the AG251FZ delivers. It’s fortuitous that we could include an AMVA display here. It has almost triple the contrast of the next best monitor. Now that 240 Hz is a practical reality, perhaps manufacturers will concentrate on upping the dynamic range ante.

Uncalibrated – Minimum Backlight Level

The backlight throttles down to a reasonable 68.9614cd/m2, which is an acceptable level for dark-room use. The black level score drops to fourth place, but only because the other screens can go dimmer. Contrast remains in third with a consistent 1002.7:1.

After Calibration to 200cd/m2

Calibrating the AG251FZ moves it ahead of the PG258Q by just a hair in the black-level test. The two monitors share their core panel part, so that makes sense. And we’ve lost no performance whatsoever, while the other screens drop their contrast just a little. Color accuracy gains are small, but if you can make the adjustments, we think the result is worth the effort.

ANSI Contrast Ratio

The ANSI test puts the AOC back in third place, but it remains solidly above the rest of the field. Despite its old-school TN technology, the AU Optronics panel used here is a brand-new part made to a high quality standard. When coupled with its insane speed capability, it takes gaming to a whole new level.

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Christian Eberle
Contributing Editor

Christian Eberle is a Contributing Editor for Tom's Hardware US. He's a veteran reviewer of A/V equipment, specializing in monitors. Christian began his obsession with tech when he built his first PC in 1991, a 286 running DOS 3.0 at a blazing 12MHz. In 2006, he undertook training from the Imaging Science Foundation in video calibration and testing and thus started a passion for precise imaging that persists to this day. He is also a professional musician with a degree from the New England Conservatory as a classical bassoonist which he used to good effect as a performer with the West Point Army Band from 1987 to 2013. He enjoys watching movies and listening to high-end audio in his custom-built home theater and can be seen riding trails near his home on a race-ready ICE VTX recumbent trike. Christian enjoys the endless summer in Florida where he lives with his wife and Chihuahua and plays with orchestras around the state.

  • apertotes
    Contrast 1000:1

  • darkomaledictus
    Won't be buying anything until that 4k, 144hz, hdr hits next year...
  • Newtoobuilding
    Would absolutely LOVE this for Quake live or Quake champions!!!!

    wonder if 1060 gtx would be anywhere close to supporting it
  • phobicsq
    I really don't see the point in 25 inches and 1080p.
  • alextheblue
    If you don't see the point in a display like this, you're obviously not in the target audience. I keep seeing comments on TN gaming display reviews that are absolutely ridiculous. This thing is about speed. Why are you reading a review of a 240hz TN gaming display? Go find reviews of different panel tech. That would be like commenting on a review of a professional IPS display, and pissing and moaning about the input lag and the low refresh rate. Do you also comment on reviews of sports cars and whine about the lack of third row seating and the low ground clearance? Simply incredible.

    Also, why is Tom's still using a 285 for their Freesync reviews? Even a 580 would help you put the display through it's paces a little bit more.
  • berezini
    LOL less product = Higher cost. Welcome to America.
  • mrmez
    20275445 said:
    Won't be buying anything until that 4k, 144hz, hdr hits next year...

    I'd like to know what graphics card would be running that.
    You know, since a 1080ti can barely crack 60fps @ 4k in GTAV.
  • Vishlod
    No CI / Common Interface? .. pass.
  • MaCk0y
    Can always use Custom Resolution Utility to increase the freesync range from 48Hz to a lower value. I have mine changed from 48 to 30. Not like it would be a good experience playing at that framerate though at least for an FPS.
  • AgentLozen
    I like the people who dismiss this monitor based on some superficial quality.

    "No CI / Common Interface? .. pass."
    "Contrast 1000:1 Next!"
    "Isn't a 10-bit AMVA panel? Skip."
    "It doesn't come in green? Try again."

    I like ALEXTHEBLUE's summary:
    If you don't see the point in a display like this, you're obviously not in the target audience...

    This Corvette doesn't seat seven passengers? I don't see the point to this car. Pass.