Response Time, sRGB Performance, DCI-P3 Performance
Response times for the PA32UC are typical for an IPS panel, I recorded a 7.18ms grey-to-grey average, while Asus reports 5ms. There six overdrive modes that Asus lists as "Trace Free", the default "60" setting introduces a small amount of overshoot that exceeds our testing threshold so I reduced it to "40", clearing that problem right up.
5ms response times are totally within the realm of possibility at high overdrive modes but the overshoot becomes unacceptable. In any case, an average response of 7.2ms for a non-gaming IPS display is decent, it's faster than a typical VA panel and well under the 16.6ms refresh window.
The main issue with the PA32UC is input lag, which is very poor. At nearly 60ms of lag in our standard test mode, this monitor is the slowest I've tested, and I couldn't find an OSD setting that improves upon this result. When you combine this input lag with the standard 60 Hz refresh rate, the monitor does feel a little sluggish to use. Again, considering response times themselves are still good, the issue with input lag only really impacts gaming; it didn't affect any of the content creation work I've been doing on the panel over the last few months.
Color accuracy is obviously a big part of how a professional monitor should perform, so it's great to see Asus providing an X-Rite i1 DisplayPro in the box with the PA32UC-K. This allows anyone buying this monitor to calibrate it continually over its lifespan, so that it remains accurate initially and for years to come. This isn't some nice addition, in my opinion this is the key selling point to the PA32UC.
But it gets better than just having a colorimeter in the box. Through the use of Asus' ProArt Calibration software tool, you can generate color accurate profiles and save them to the monitor. This is an absolute godsend for content creators, because software profiles you set within Windows can only get you so far, as not every application supports or adheres to basic ICC profiles.
With the PA32UC, you can basically ignore software profiles altogether, and just save the profile directly into the monitor's firmware. Then you can not only use your exact calibrated profile with your main PC, but with any device you hook up to the monitor, including those that don't allow software-side calibration like a Blu-ray player, game console or Chromecast.
The ProArt Calibration software is super easy to use, you can set your color space, brightness, gamma and white point targets, then you just plug in the i1 DisplayPro to the monitor, the tool gets to work, and you can save your profile into one of two user profile slots. Having two slots is also important, because you can then have an accurate sRGB profile, and an accurate DCI-P3 profile (for example), allowing you to switch between them whether you're working with wide gamut content or not.
Calibrated sRGB Performance (Asus ProArt Calibration Utility)
Asus' own software isn't as accurate as SpectraCAL's CALMAN 5 that we normally use for display calibration, but it still gets the PA32UC to a point that content creators should be happy with. When calibrating to sRGB, I was able to achieve a greyscale deltaE below 2.0, decent enough white balance, good gamma, and both saturation and ColorChecker deltaE averages around that 1.0 mark which is basically dead accurate. Combined with 99.5% sRGB coverage and that's a fantastic result for color accurate work, especially as this profile is saved directly to the display itself, and you can re-calibrate the monitor as many times as you like over the lifespan of the display.
Calibrated DCI-P3 Performance (Asus ProArt Calibration Utility)
For DCI-P3, calibrated results weren't quite as accurate for greyscale with a bit of wonkiness to the CCT curve, however color performance was still very accurate with deltaE averages of 1.07 and 1.22 for saturation and ColorChecker tests respectively. So after running the Asus wizard with the tool provided in the box, you can quite easily send accurate sRGB and wide gamut profiles to the monitor, which is exactly what you want from a professional grade monitor.
Those who want even greater levels of accuracy, which probably isn't necessary unless you have strict deltaE standards of sub 1.0 for perfect accuracy, could use CALMAN 5 to create a software profile, which could be used in conjunction with the on-display profile for extreme accuracy. As you might expect, here we were able to create a very accurate profile with essentially no issues.
There are a few other reasons why having the calibration tools provided is great for buyers. There are lots of professional grade monitors out there that come with profiles calibrated at the factory, including the PA32UC, which definitely gets you part of the way there. But often these profiles come with restrictions, for example with the PA32UC's factory sRGB mode, there is no way to change the brightness level, you're stuck at 165 nits. Using the calibration tools allows you to set a brightness target yourself. Monitor accuracy degrades over time, so factory calibration will be less accurate a year after you purchase the display. Again, the included calibration tool means you can continually ensure the display is accurate.
Calibration also allows you to correct errors with factory calibration. In the case of the PA32UC, the default factory sRGB mode uses a 7500K white point target, rather than the correct 6500K. This is a bit bizarre for a professional monitor targeting sRGB, and if the calibration tools weren't provided I'd slam Asus for this mistake, because the factory profile is not accurate. But when the tools are there, I'd recommend and expect anyone purchasing this display for professional use will perform a calibration after taking it out of the box, which corrects the problem and really makes it less of an issue.
The final area of performance I want to look at is uniformity. Again, this is an area Asus allows you to calibrate using their ProArt Calibration software, which is unique because calibrating uniformity is often very difficult aside from these sorts of tools. Naturally, I'd recommend buyers use the uniformity calibration tool straight out of the box, alongside a full color calibration.
However even with a uniformity calibraton, results are a little weak for a professional grade display. It's definitely good overall, especially in the center of the display, but for a pro-grade monitor I'd want the entire screen reporting in with a sub-2.0 deltaE relative to the center. Some outer areas are up over 3.0, and I suspect this is partially down to the FALD backlight. Getting an even result out of this sort of backlight is tricky.
I guess the disappointing thing here is uniformity is actually worse for this monitor compared to the gaming grade Acer Predator X27 which also uses a 384 zone FALD backlight. That monitor also features better factory calibration, though it doesn't support some of the calibration features I've been talking about throughout this review.