Review Index:

ASUS PQ321Q 31.5-in 4K 60 Hz Tiled Monitor Review

Author: Ryan Shrout
Subject: Displays
Manufacturer: ASUS

Setup Process on AMD and NVIDIA, Dual HDMI Testing

Unfortunately for ASUS, setup and use of the PQ321Q isn't quite as simple as plug and play quite yet.  In our initial testing video you saw some of our problems and conflicts getting the monitor up and running on both AMD and NVIDIA test beds - it was kind of annoying and embarrassing enough for NVIDIA to get them to push out a new driver to address SOME of the problems in under a week.  But let's talk about the better experience first with AMD.


Setup with AMD Radeon HD 7000-series

Connecting the ASUS PQ321Q to our AMD Radeon HD 7970 GHz Edition card via the included DisplayPort cable was by far the easier of our two experiences.  With the monitor turned on and MST mode enabled in the DisplayPort STREAM options, we booted into Windows right away but the OS and driver was seeing either head of the display as a unique monitor.  As a result, we had the start menu of Windows 8 on the left hand side and your standard desktop wallpaper on the right hand side.  But, right away, the screen was usable as AMD has identified each panel and set it up as a spaned display configuration, each at 1920x2160.

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Great, but how do you set it up as a single display with a single resolution?  Eyefinity.  I entered into the AMD Catalyst Control Center and ran the standard Eyefinity configuration utility and created a two-panel option.  Boom - we were up and running.

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As with any other Eyefinty result, the operating system sees a single panel, but we just happen to be running it at 3840x2160 with a refresh rate of 60 Hz. 


Setup with NVIDIA GeForce GTX 700-series

Things weren't quite as simple with NVIDIA as it turned out.  There are some bugs and issues that were addressed with some driver fixes they shared with me this week but there are other problems that won't be addressed until a new firmware is pushed out by ASUS and STMicro later in the month.  The first problem was an occasional ability to fail a cold boot - the motherboard would sit and stare at me with a "62" on the POST code and do nothing else until I hit the reset button.  Afterwards, it would start over and make its way into Windows nearly 100% of the time.  Annoying, but workable.

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Another potential problem was the lack of ability to see the POST screen and BIOS during boot - most of the time our PQ321Q only showed something on the panel when we had entered Windows 8 and gotten to the login screen.  That can be pretty annoying and would require a user to have another monitor handy if any troubleshooting ever needed to happen with their rig.

In my experience it was also very hard to get anything on the screen if you don't at first boot into Windows with your NVIDIA graphics card with the monitor in SST mode rather than MST mode.  Once you are in Windows, you can switch the panel to MST mode and the system will recover, and you can reboot back into Windows each time after that without switching modes.

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After talking with NVIDIA and ASUS about these problems, both companies seemed very confident that most of if not all would be addressed with a forth coming firmware updated provided by STMicro and pushed out by ASUS to its customers.  The current estimate for that release is the end of July so I'll be sure to test out the changes once we have the FW installed on our test unit.  (A recent driver release by NVIDIA helps with some other compatibility issues.)

After finally getting MST mode working over the DisplayPort cable with our NVIDIA GeForce GTX Titan graphics card, the rest of the setup is actually easier than you have with AMD.  NVIDIA has never supported 2x1 Surround configurations on GeForce graphics cards and that doesn't really change with these driver releases.  Instead, NVIDIA is looking for these panels as a matter of special case and configuring the setup automatically for you.  There is no need to go into the driver and setup a grouping or tell it which side is right or left, etc.

In truth, that is the promise of the upcoming VESA 1.3 standard that includes new requirements to make tiled displays a better supported category.  Once THAT firmware is released by ASUS (they are claiming later in the year) and with further tiled monitors, the display and graphics card will communicate without user intervention about how many heads are included, their orientation and refresh rates and set it up automatically.  NVIDIA is basically attempting to emulate this with updated drivers but it will be an industry wide feature once VESA 1.3 becomes the norm.


Dual HDMI Testing

I had several readers asking about the support for Dual HDMI mode with the ASUS PQ321Q and I have had mixed results.  Because none of the graphics cards on the market (or at least that I have here) include dual HDMI 1.4 outputs, I was forced to use one native HDMI connection and then adapt either a DVI or DP connection to HDMI for the second input.  With AMD, no collection of adapters would allow me to run 3840x2160 at 60 Hz and after a talk with AMD it seems that we need an ACTIVE DisplayPort to HDMI 1.4 adapter (which I have ordered but are still not yet available) to get it to work correctly.  You are able to run at 4K resolution with a 30 Hz refresh rate but that kind of defeats a primary selling point of this $3500 monitor.  So currently dual HDMI mode appears to be out for AMD cards.

The same was true for NVIDIA last week but over the last few days they were able to provide a brand new driver (not the one posted publicly this week) that was able to enable 3840x2160 @ 60 Hz using the native HDMI port and a passive DVI to HDMI adapter for the second input.

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With this driver and configuration the system acted identically to when it was connected via DisplayPort with MST enabled.  Yes, that does include the POST and cold boot issues, but once in Windows it was seamless.

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Obviously there is a lot left to be desired still for the ease of setup and configuration of the ASUS PQ321Q monitor.  The AMD setup experience was by far the easier of the two but NVIDIA made a lot of strides with a couple of driver revisions in the last seven days.  Most of the other problems with NVIDIA will likely persist until a firmware update or two filter their way out.

July 26, 2013 | 07:14 AM - Posted by Anonymous (not verified)

Is there any unusual behavior when doing MST with either the monitor put into portrait mode directly via OSD, or through windows control panels? How the drivers react to portrait mode can be a problem. Additionally, how are the viewing angles when in portrait mode, as many displays have polarization filters that look fine in landscape, but in portrait orientation screw up the brightness as perceived by the eye. Finally, it appears the control buttons are sufficiently recessed so you can align multiple monitor bezels to touch each other without pressing them, but can you confirm that?

July 26, 2013 | 11:40 AM - Posted by Anonymous (not verified)

The need for MST or tiling in general makes me think now isn't really the time for 4k on the desktop, unless you're working in an industry that can very obviously make use of the added resolution.

I'd rather wait for the next revision of DP or HDMI so the monitor can be driven at native res, at 60 or even 120Hz with just one proper connection. That pretty much means waiting for the next generation of GPUs and monitors.

July 31, 2013 | 09:24 AM - Posted by Anonymous (not verified)

The new driver version 326.41 adds support for tiled 4k monitors.

August 6, 2013 | 12:45 PM - Posted by Anonymous (not verified)

what about three of these in eyefinity :) ?

August 22, 2013 | 07:33 AM - Posted by Anonymous (not verified)

Has anyone tried hooking up 3 PQ321Q in one machine?
Do u think it is doable?

October 6, 2013 | 12:28 AM - Posted by gohkg (not verified)

Hi, wonder if anyone can help. Bought a Asus PQ321, the display is great but somehow i cannot set it to 60Hz using MST whether be it using a GTX690 or AMD 6990 graphics card. Always one half of the panel is blank after setting MST for either cards and both cards cannot detect the blank half and for AMD i cannot even set up Eyeinfinity group...thanks.

December 24, 2013 | 05:01 AM - Posted by ZaraPerkins (not verified)

What do you think about the Sharp, its cheaper and has the same 4k technology, pretty interested to see if there is much of a difference that matters in price point here. Thanks for any help or advice.

December 24, 2013 | 05:03 AM - Posted by ZaraPerkins (not verified)

What about the Sharp PN?, similar in 4k technology but the price points much less for the Sharp, what would be your bigger decision factor between the two?

February 28, 2014 | 02:29 AM - Posted by kiwi (not verified)

This screen runs 4k @60hz, on the new Mac Pro. I have a new Mac Pro (since two days ago), but I don't have this screen yet. I'm about to order it.
This screen, and the Sharp PN-K321, are the two screens whitelisted on apple support page, as running 4k @60hz.
No doubt that list will grow as drivers and stuff get sorted.

Note that SwitchResX gives you a gazillion times more control over the available screen resolutions and refresh rates on Macs. You can even do your own custom ones. So anyone who can't get particular resolution or refresh rate that they want, give SwitchResX a try.

And to mLocke who wants 120hz to become mainstream, well I'm doing my bit. On my MacBook Pro 15"" Retina, mid 2012, and using SwitchResx, I was able to get 1920 x 1080 @120hz (on an Asus VG248QE). 120hz is stunning. (It needed the Apple mini display port to dual link DVI adaptor)

November 25, 2014 | 09:06 PM - Posted by Anonymous (not verified)

How do i do this with intel integrated graphic???

At the moment i'm running the 4k at 3000x1600 and 45hrtz.
When i try to combine it just goes to 30htz

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