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Measurement And Calibration Methodology: How We Test

Asus ROG Swift PG278Q 27-inch G-Sync Monitor Review
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A Quick Word About G-Sync Testing

G-Sync only affects synchronization between the video signal’s input and output refresh rate. Because of this, it either works or it doesn’t. There is no test we can think of that would demonstrate the superiority of its implementation in one monitor over another. For this, and all subsequent G-Sync product reviews, we’ll be sticking to our usual battery of display tests.

In the case of the PG278Q, we’ve added tests to determine the impact of ULMB (backlight strobe) on light output. You’ll find them on page ten.

To measure and calibrate monitors, we use an i1Pro spectrophotometer, a Spectracal C6 colorimeter, and version 5.2.0.1374 of SpectraCal’s CalMAN software.

The i1Pro is both accurate and consistent measuring color on all types of displays, regardless of the backlight technology used. When we just need a luminance value, the C6 works better, especially in low light.

For patterns, we employ AccuPel DVG-5000 and DVDO AVLab TPG video signal generators. This approach removes video cards and drivers from the signal chain, allowing the display to receive true reference patterns. Connections are made via HDMI.

The AccuPel DVG-5000 is capable of generating all types of video signals at any resolution and refresh rate up to 1920x1080 and 60 Hz. It can also display motion patterns to evaluate a monitor's video processing capabilities, with 3D patterns available in every format. This allows us to measure color and grayscale performance, crosstalk, and ghosting in 3D content via the 3D glasses.

The DVDO generator is a new addition to our lab. It supports resolutions up to 4096x2160. We’re using it to verify the proper signal handling of QHD and UHD displays.

The i1Pro or C6 is placed at the center of the screen (unless we’re measuring uniformity) and sealed against it to block out ambient light. The AccuPel pattern generator (bottom-left) is controlled via USB by CalMAN, which is running on the Dell XPS laptop on the right.

Our version of CalMAN Ultimate allows me to design all of the screens and workflows to best suit the purpose at hand. To that end, I’ve created a display review workflow from scratch. This way, we can be sure and collect all the necessary data with a concise and efficient set of measurements.

The charts show us the RGB levels, gamma response, and Delta E error for every brightness point from zero to 100 percent. The table shows us the raw data for each measurement. And the area in the upper-left tells us luminance, average gamma, Delta E, and contrast ratio. The individual charts can be copied to the Windows clipboard to easily create graphics for our reviews.

Every primary and secondary color is measured at 20-, 40-, 60-, 80-, and 100-percent saturation. The color saturation level is simply the distance from the white point on the CIE chart. You can see the targets moving out from white in a straight line. The further a point is from center, the greater the saturation until you hit 100 percent at the edge of the gamut triangle. This shows us the display’s response at a cross-section of color points. Many monitors score well when only the 100-percent saturations are measured. Hitting the targets at the lower saturations is more difficult, and factors into our average Delta E value (which explains why our Delta E values are sometimes higher than those reported by other publications).

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  • 6 Hide
    ubercake , August 11, 2014 9:08 AM
    That Amazon link is to the PB278Q, not the PG278Q! ARRGGGGHHHHH!!!
  • 2 Hide
    TechyInAZ , August 11, 2014 9:12 AM
    Nice! This is great since I am one of those picky guys that believes that 30fps doesn't bring a good enough gaming experience.

    But one thing I do hope for is a 144hz g-sync IPS monitor, ever since I've gotten my new Asus MX239H the ips makes a huge difference in games.

    But besides that, it is a glorious monitor, resolution is great, 144hz, and of course g sync makes it a wonderful monitor.

    But really $800? I know that it is one of the few g sync equipped monitors, but you can buy a 4k monitor for $650!
  • 7 Hide
    CraigN , August 11, 2014 9:29 AM
    Yes - please fix that Amazon link. I almost shat myself thinking that was available already.
  • 0 Hide
    apertotes , August 11, 2014 9:36 AM
    Anybody knows if the incompatibility between G-Sync and ULMB is something that will get fixed or is here to stay?
  • 0 Hide
    CraigN , August 11, 2014 10:09 AM
    Quote:
    Anybody knows if the incompatibility between G-Sync and ULMB is something that will get fixed or is here to stay?


    Pretty unlikely. ULMB requires a static refresh rate, because it has to strobe the monitor at a constant rate. GSYNC would mean that it would have to strobe in time with each frame, at a variable rate. You would introduce a lag time on the strobing if you tried to do this, since it would be at a variable rate instead of a constant one.
  • 3 Hide
    rh_dog , August 11, 2014 10:43 AM
    I know it's expensive for 2560x1440, I know it's not IPS, but to get the refresh rate @144hz and the 1ms g2g and g-sync? The few reviews for this monitor that are out there are all glowing. Come on, Asus, release the thing already, I've been waiting since the Jan announcement for this monitor. Shut up and take my money!!!
  • 1 Hide
    pchampn , August 11, 2014 11:21 AM
    Guys ROG Swift PG278Q is not even listed on Amazon. Update your links, please!!
  • 3 Hide
    Rendezvous , August 11, 2014 11:29 AM
    Omg! I need this now..... I alrdy have 800 set aside for it...I need a exact release date now!
  • 0 Hide
    agentbb007 , August 11, 2014 11:48 AM
    Asus has said on Twitter it should be in the US by the end of August. I can't wait for this, I'm checking newegg everyday to see when it shows up! I hope they have enough of these coming in because there seems to be a lot of people waiting to buy this monitor.
  • -2 Hide
    Merry_Blind , August 11, 2014 11:53 AM
    Yayy finally a review for this monitor! Thanks Tom's!

    Off to read it now! lol
  • 2 Hide
    Rendezvous , August 11, 2014 12:24 PM
    Quote:
    Yayy finally a review for this monitor! Thanks Tom's!

    Off to read it now! lol


    There have been plenty reviews for this monitor just Google it. And they have all been great reviews...makes me want it even more
  • 0 Hide
    Merry_Blind , August 11, 2014 12:24 PM
    As amazing as this monitor looks, it still sucks that you can't use ULMB with G-Sync.

    Personally, I'm sick of the crappy motion resolution in LCDs. It's not so bad in some games, but it's nigh-unbearable in certain games. My next monitor/TV WILL have Strobing-Backlights since it's the best way to get rid of motion blur.

    However, maybe someone can help me out on this, I don't understand why monitors that feature such motion-enhancing technologies seem very nitpicky with which frame rate, refresh rate, etc. it's being used with. I'm saying this because more and more TVs are coming out with such Strobing-backlight technology, and I'm pretty sure those don't require an absolute steady framerate for it to work.

    For example, if I were to connect a console to this ASUS Swift monitor, could I use ULMB in 120hz mode with a 30fps game?
  • 0 Hide
    CraigN , August 11, 2014 12:47 PM
    No, because the console won't output 120 Hz, especially not through HDMI to DisplayPort conversion.

    It's not the framerate they're being picky about, it's the refresh rate. The light has to strobe in time with when the next frame is being introduced. When the refresh rate is constant (i.e., locked at 80, 100, or 120 Hz) then the strobe knows exactly when the next frame will be displayed. You're asking the display to strobe the backlight at will whenever the GPU can put out a frame. You're essentially asking the GPU to not only handshake with GSYNC when to render a frame, but to trigger the backlight to strobe then too. The tricky part here is that's another layer where you will have to reduce response time (response from the GPU's frame being rendered to backlight being strobed) since the refresh rate is no longer constant (it's now dependent on your game's refresh rate - which is barely ever anywhere near "constant").

    How awful would your strobing backlight look if it came a few ms after your frame rendered? That'd probably screw all of the blur reduction qualities you want from it. At best, you could make an algorithm that would strobe at the *average* framerate you're outputting since framerate can rise and dip so quickly, but that could still cause a lot of problems
  • 0 Hide
    agentbb007 , August 11, 2014 12:53 PM
    Quote:

    For example, if I were to connect a console to this ASUS Swift monitor, could I use ULMB in 120hz mode with a 30fps game?

    I'm definitely not an expert on ULMB or Gsync but the blurbusters website says "LightBoost motion blur elimination is not noticeable at 60 frames per second." So even if you could get a console hooked up to the Asus Swift I don't think you would be able to notice any difference unless you get 85+ fps.
  • 0 Hide
    Merry_Blind , August 11, 2014 12:57 PM
    Quote:
    Quote:
    Yayy finally a review for this monitor! Thanks Tom's!

    Off to read it now! lol


    There have been plenty reviews for this monitor just Google it. And they have all been great reviews...makes me want it even more

    Oh I know that, it's just that I was waiting for Tom's Hardware specifically to do a review since I like their reviews!
  • 0 Hide
    Merry_Blind , August 11, 2014 1:08 PM
    Quote:
    No, because the console won't output 120 Hz, especially not through HDMI to DisplayPort conversion.

    It's not the framerate they're being picky about, it's the refresh rate.


    Ok, let's forget consoles then for a second, because I didn't think of the fact that they can't output at 120hz. If, for example, I had my PC hooked to the Swift monitor, set to 120Hz, and that the game I play has a fluctuating framerate going anywhere from 30fps to 90fps. Would I be able to use ULMB since the monitor is running at 120Hz? Despite the framerate being all over the place, and not ever at 120fps?

    Thanks for your reply btw.
  • 0 Hide
    Merry_Blind , August 11, 2014 1:09 PM
    Quote:
    Quote:

    For example, if I were to connect a console to this ASUS Swift monitor, could I use ULMB in 120hz mode with a 30fps game?

    I'm definitely not an expert on ULMB or Gsync but the blurbusters website says "LightBoost motion blur elimination is not noticeable at 60 frames per second." So even if you could get a console hooked up to the Asus Swift I don't think you would be able to notice any difference unless you get 85+ fps.

    But like I said, more and more TVs are being released with a 'Black-Frame insertion' option, and from reviews, it gets rid of motion blur very well, even for a movie, which plays at 24fps.
  • 0 Hide
    CraigN , August 11, 2014 1:18 PM
    Quote:

    Ok, let's forget consoles then for a second, because I didn't think of the fact that they can't output at 120hz. If, for example, I had my PC hooked to the Swift monitor, set to 120Hz, and that the game I play has a fluctuating framerate going anywhere from 30fps to 90fps. Would I be able to use ULMB since the monitor is running at 120Hz? Despite the framerate being all over the place, and not ever at 120fps?

    Thanks for your reply btw.


    No problem. I enjoy discussing the topic.

    Yes. You would. Because with ULMB on, the REFRESH RATE stays constant, despite your varying frame rate. The monitor (In regular, or in ULMB mode, with Gsync off) will only refresh the frame at a rate of every 8.33 ms (1 / 120Hz), regardless of your framerate. This has nothing to do with the 1ms response time. That's where your keyboard or mouse input lag comes in. This is also what causes horziontal tearing, which is what GSYNC aims to remove. If your FRAME rate is much higher, or much lower, than your monitor's REFRESH rate, you will observe lots of tearing. ULMB does not reduce tearing, just motion blur.

    You don't have to hit 120 fps to refresh at 120 Hz, but you get the most benefit out of your monitor that way. So yes, you can play ULMB at any framerate, but you *will* notice stutter if you're playing in the 90s and then drop into the 30s. This is what traditionally VSYNC tries to remove, but introduces input lag as a side effect.

    Gsync removes the stutter and the tearing with virtually no input lag. It makes it so your monitor will refresh at the same rate as your framerate. So if you set your monitor to 144 Hz, and turn GSYNC on, then suddenly your *Max* framerate becomes 144 Hz (can't update faster than the panel), and the refresh rate of the monitor (when the monitor displays new frames from the GPU) varies with the framerate of the game from any range of 35 FPS up to 144 FPS. If you drop below 30 FPS, the GSYNC module switches to traditional VSYNC.

    GSYNC can be toggled on and off from the Nvidia Control Panel. This is how you can switch between GSYNC or ULMB depending on what type of game you want to play.
  • -7 Hide
    redgarl , August 11, 2014 1:45 PM
    It's made by Asus and it is not a motherboard... stay away from it...
  • 5 Hide
    CraigN , August 11, 2014 1:49 PM
    Not sure why you feel that way. Several of their other products I own have been outstanding. My VG248QE is great and so is my G750JX laptop. Their $650 4K monitor got fantastic reviews.

    Some of their lower-end products have some quality issues I hear, but you see that in Dell, HP, Acer... It's not exactly a new trend.
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