Overlord Tempest X270OC, 27" 120 Hz IPS Gaming Monitor Review

After many reader requests to review Overlord’s 120 Hz 27-inch QHD monitor, we finally got a brand new X270OC in our labs. It’s the only IPS screen we know of that can exceed a 60 Hz refresh rate. We run it through our benchmark and usability test suite.

Over the past few months, we’ve covered several gaming-oriented monitors capable of refresh rates greater than 60 Hz. They all performed extremely well, and certainly lived up to their speedy specifications. But there was one thing still lacking: higher resolutions.

In the current market, a high-refresh gaming monitor is always based on a TN panel with a 6-bit/FRC color depth and FHD resolution. The speed issue is addressed decisively. Moreover, the screens that have come through our lab performed well with regards to color accuracy. However, enthusiasts plead for the greater pixel density of QHD and the superior viewing angles of IPS technology.

So far, the only company to answer that call with a quality-controlled and warrantied product is Overlord Computer, a small firm that markets gaming accessories and peripherals.

Panel Type
W-LED, edge array
Screen Size
Max Resolution
Max Refresh Rate
60 Hz, up to 120 Hz
Aspect Ratio
Native Color Depth
Native Gamut
Response Time (GTG)
6 ms
380 cd/m2
2 x 10 W
DisplayPort v1.2
HDMI 1.4
Audio  In
1 x 3.5 mm
Media Card Reader
Panel Dimensions
WxHxD w/base
25.25 x 19 x 8.5 in
636 x 479 x 214 mm
Panel Thickness
2.5 in / 63 mm
Bezel Width
.95-1.55 in / 24-39 mm
15 lbs / 6.8 kg
One year

Overlord’s best-selling line of monitors is the Tempest series. For gamers seeking the extra size and pixel density of a 27-inch QHD display, there are several different models available. You can have one with or without an anti-glare layer, for instance. Removing that layer improves clarity and detail rendering. If you can manage the light sources in your room, it’s a compelling option.

Of course, this company's main attraction is its overclockable panels. Right now, the Tempest is the only IPS screen capable of refresh rates higher than 60 Hz. And its pricing is significantly below the average for even run-of-the-mill QHD monitors. In fact, the only less-expensive ones we know of are the gray-market Auria and Catleap screens. Neither of those run above 60 Hz reliably, though.

The key to Overlord’s success with the X270OC is a custom-made control board. That single component is the reason other IPS screens are stuck at 60 Hz. You can perform the same software tweaks necessary to run at 120 Hz on other monitors, but unless the board is equipped to handle those extra frames, you'll likely see either an unusable image or nothing at all.

The Tempest monitors are essentially hand-built using an A-grade LG panel as their core part. The proprietary control boards are tested before installation to be sure they can handle higher rate signals. Heat is minimized in the chassis by utilizing external power supplies. And the end result is the only 2560x1440 monitor available able to run at 120 Hz.

Otherwise, the X270OC is a very typical 8-bit sRGB IPS QHD monitor with a W-LED edge backlight. It runs your Windows apps, games, and other software no differently than any other display. Our press sample was tested to 120 Hz prior to shipment, and we verified its operation with our test platform. But this is no one-trick pony. We discovered it performs well in other areas too. Let’s take a look.

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  • oudmaster
    the price is interesting with these specs !
    any idea if there will be a similar monitor spec but 4k resolution ?

  • oudmaster
    the price is interesting with these specs !
    any idea if there will be a similar monitor spec but 4k resolution ?

  • oudmaster
    [No message]
  • wtfxxxgp
    Crickey me...this is a monitor of note it seems! At that price point, I find it incredible. Well done to Overlord! The only issue I have now is... will the price increase as a result of all the buzz this will generate? This is probably going to be my next monitor, depending on exchange rates...
  • Shneiky
    4K at 120 MHz? Not in the next 5 years.
  • Swiperd3
    Driving QHD to 120 FPS at the max graphics detail is sure as hell will require A LOT of horsepower. Will TOP-SLI/CF-x2 be enough for modern FPS games?
  • Traciatim
    Wow, you get this with one of the variable sync techs and you have yourself one fantastic monitor.
  • waxdart
    16:9 :(
  • envy14tpe
    Thank you Thank you Thank you. I've been dying to see a review on this monitor.
  • Reaver192
    Yeah, I've been waiting fir this for too long. I wanted one of these months ago but they have been out of stock. Such a sweet deal
  • avatar_raq
    This is the holy grail of PC monitors, if only it comes with 120 Hz guaranteed out of the box.
  • yogalD
    I wish it had a strobe backlight though, that would make it perfect
  • Durandul
    If it had an option for Display port, that would have been almost perfect. That being said, I use DVI anyway, so who am I to complain.
  • MonsterCookie
    This is already a step at the good direction. Even the price in $ looks decent.
    Question is how much will this cost here in Europe.

    Also, now make the same thing happen in a 30" format with 2560x1600 resolution, and than I am definitely opening my wallet.
  • mapesdhs
    MonsterCookie, alas I doubt that will happen. A few years ago, 1440 and 1600
    height monitors were priced basically the same, ie. expensive. Back then, top-end
    GPU reviews tended to use 2560x1600 as a typical max res test for gaming. But
    then buying patterns evolved, the usual feedback between pricing and demand,
    people tended to opt more and more for 1440 displays instead. As a result, when
    I wanted to get a 1600 IPS a while ago, I was amazed to find 1600 hieght displays
    were about 4X more expensive than 1440 IPS models.

    Presumably it suits the industry to home in on a more typical standard, and for
    the moment, beyond HD, 2560x1440 seems to be it. Very unlikely the industry has
    any interest in pushing 1600 height to the masses, so probably the next main step
    up will be to 4K, or as I wish they'd call it instead, quad-HD.

  • ubercake
    The specs look goood, but the key is they don't guarantee 120Hz for all OC monitors:

    It's like hoping you'll get an i7 that will have a stable OC to 4.5Ghz 24/7. It's the luck of the draw.
    I don't much like putting my money on hope. If they did have a guarantee or just sold a monitor that shipped to my house with 120Hz capability, I'd be more likely to hand over my cash.

    You know darn well they make sure the review site is getting a good one.
  • daglesj
    So does it work fine at say 90Hz and if so is that an improvement?
  • npyrhone
    Thanks a million for the review! This will be next monitor. Hallelujah! Lacking a decent non-TN gaming panel, I've played with a pro 24" CRT for all these years.
  • npyrhone
    A few answers and corrections concerning ideas thrown around in this thread:

    1) Yes, This works perfectly at 90Hz. Yes, it is a great improvement. Much greater improvement is 60->90 than 90->120.

    2) All monitors are from this day to the future to come 16:9. So, its useless to fancy 16:10 monitors anymore, they wont be coming ever again.

    3) 4K 120Hz gaming monitors wont be coming, either. At least not in the foreseeable future.

    4) Overclocking this is not luck of the draw. They all come at least 96Hz, and the great majority work 120Hz.

    5) The lack of displayport etc is what helps keeping input lag low.
  • rishiswaz
    I wonder why they don't just have another model with cherry-picked panels that they ship at 120 out of the box
  • xenol
    An up to 120Hz IPS 1440p IPS monitor for $450?

    Dammit HP, where were you last year when I bought a 1440p monitor?
  • InvalidError
    705201 said:
    5) The lack of displayport etc is what helps keeping input lag low.

    A synchronous digital multiplexer operating at 1GHz adds maybe two nanoseconds to propagation delays. You would need a horribly poor design for the number of inputs to actually have any measurable effect on lag.

    Where displays get most of their input lag from is image processing when they do things like dynamic contrast and power-saving backlighting.
  • rishiswaz
    I think the lack of display port is cost saving, not really as standard as DVI and probably cheaper to make the ports
  • jerrolds
    I was the *first* Overlord Tempest OC owner lol - pre-order #8 (1-7 were test orders) back in Aug 2013

    Great monitor - back then 1440p 120hz IPS was unheard of, only Catleap 2b monitors were capable. And it was $650 at the time.