Gaming at 4K on the PQ321Q
First up, a confession: we don't have benchmark numbers that were captured on the ASUS PQ321Q quite yet. But here's the secret – we already have relevant 4K testing results from our first article that are completely valid for looking to compare the latest cards from AMD and NVIDIA at super-high resolutions like 3840×2160. If you haven't already read that story I would suggest you do so but I have a couple of graphs I'll include here to set an example.
Gaming at 4K with a 60 Hz refresh rate is definitely a different experience than gaming at 30 Hz. If you like to game with Vsync disabled then you'll be glad to know that the horizontal tearing that occurs will be much less frequent when the display operates at 60 Hz than when it operates at 30 Hz. Not only that but the mouse movement is definitely more responsive with a 60 Hz panel than at 30 Hz, but it isn't as big of a deal as it was in the standard Windows desktop environment.
It should come as no surprise that the single fastest GPU for gaming at 4K resolutions is the GeForce GTX Titan. Since those tests were run, NVIDIA has released the GeForce GTX 780 and GTX 770 so we will be doing some more testing in the coming days, but AMD's single-GPU Radeon HD 7970 GHz Edition can definitely hold its own.
There are other concerns to be aware of with gaming on the ASUS PQ321Q that didn't exist with the SEIKI SE50UY04 we tested in April. Most importantly is that the ASUS monitor is a tiled display meaning the NVIDIA and AMD graphics cards are sending output to two distinct display heads. Essentially, we are running in either Eyefinity or Surrond mode depending on your graphics card vendor. As we have seen in previous GPU testing with our Frame Rating capture-based system, introducing multiple displays can complicate things in a negative way and adding in SLI and CrossFire makes things even more complex.
After another quick trip and Quakecon 2013 we'll be back in the office to dive into this issue head-on and we'll be sure to report back any additional complications that pop up with our real-world testing capabilities.
Another interesting topic for gaming at 4K resolutions is whether or not you'll need antialiasing technology anymore. The argument basically says that with sufficient pixel density, the benefits of smoothing out lines with AA becomes much less apparent to the human eye. There is definitely truth to this statement, but in my game testing with the PQ321Q there were still plenty of cases where turning off AA result in jaggies and "shimmers" in objects that were improved with AA enabled. Skyrim was one such example:
While I know that taking screenshots from the game and posting them here isn't exactly going to emulate what I was seeing as a gamer, the screenshots do a decent job emulating it in this case. While actually moving in the game world around that tree the lack of antialiasing was even more apparent than in the stills shown above.
That being said, in Crysis 3, at Very High presets, I couldn't really tell the difference with AA enabled or disabled and playing a few minutes of the game. Obviously texture quality on a game to game basis will mean a lot when it comes the continued need for AA in gaming on displays with pixel density this high.
Finally, I did have a request to check how gaming at 1920×1080 would look on this panel for users that didn't have the GPU power to push 4K pixels but were interested in the ASUS PQ321Q for desktop and productivity usage. Bad news to report here: as of today the firmware of the STMicro controller does not support scaling non-MST resolutions on the fly. Changing the resolution in the Windows control panel essentially breaks the Eyefinity or Surround configuration.
In this image, trying to enable a 1920×1080 resolution on an AMD card results in mirrored, incorrect aspect ratio displays. With NVIDIA the result was similar but was not mirrored. As it turns out, if you want to run full-screen at 1920×1080 you will have to change the PQ321Q into SST DisplayPort stream mode which requires a reboot of the panel and likely of your machine. ASUS told me they were working on the capability to scale without changing from MST mode but didn't have any time frame for when that might be ready.