PC gaming is all out extreme performance and eye-popping visuals. DirectX games on Windows are always pushing the boundaries of the latest graphics hardware and software technology that will bring things “to the next level”. In this article I’m going to share with you an amazing set of experiences that I recently had pushing the boundaries of 4K multi-mon gaming with several Sharp PN-K321 4K Ultra HD displays that I had on loan for a short period of time. I’ll start with some scenarios that have been tested before and then walk through a technology demonstration and collaboration that I worked on with AMD to see how far we could push things. Let’s just say this was an intense experience!
Ever since I had my first taste of 4K resolution gaming on Windows 8 (which you can read about here) I’ve been wanting to explore some additional related scenarios. First, I was thinking it would be awesome to try 4K multi-mon gaming. Second, I wanted to see how the 4K gaming experience would change when the screen refresh rate was pushed from 30 Hz to 60 Hz. Finally, I thought it would be amazing if I could push a tri-mon 4K setup to 60 Hz. Things were about to get real interesting.
12K Multi-Mon PC Gaming
So there I was rolling a cart with $15,000 worth of displays towards the lab. What am I going to try first I asked myself… How about a 3×1 12K setup with a DirectX 11 game? I couldn’t wait to get started.
The first question that I had was how I was going to connect these displays to a PC. I then pondered how much graphics horsepower I would need to run a DirectX 11 game at 30 Hz (the highest frame rate possible over single-stream connections). I called up my friend Jeff from AMD to discuss this project, and he said “I have just the video card for this”. Jeff brought over an ASUS HD 7970 DirectCU II card that is equipped with four full-size DisplayPort outputs.
Once the displays were setup and connected via DisplayPort, I created a 3×1 Eyefinity display group in the AMD Vision Engine Control Center. Wow! A display surface with a resolution of 11,520 x 2,160 – amazing!
I opened the Display Control Panel and confirmed that Windows now saw this Eyefinity display group as a giant display surface:
This setup is the equivalent of 12 1920×1080 displays, that’s a total of 24,883,200 pixels! The last time I tried DirectX 11 gaming at 4K I used a single AMD 7970 card and was able to hold 30 Hz no problem with Max Payne 3. Now I was about to find out how the same graphics hardware would perform with three 4K displays running at 30 Hz. I decided to run Dirt3 since the panoramic effect of 3 displays would work well with that game. Would this setup be able to hold 30 Hz with a single AMD 7970 graphics card? I was about to find out!
Running Dirt3 at 11,520 x 2,160 with settings maxed out resulted in a frame rate just below the 30 Hz target. I closely examined my graphics settings, and was able to turn off some features that optimized the gameplay experience. One of the most important changes I made was to turn off multisampling as it’s not important at high resolutions and it does impose a performance penalty. Settling on medium to high overall settings I was able to hold an average frame rate of about 35fps. Because I was not dropping frames with this setup the overall gameplay experience was awesome, and the sheer quantity of pixels was truly like nothing I’ve experienced before!
This was an awesome setup, but I was also wondering how the 4K 60 Hz gaming experience would feel. The next logical step was to try out the MST (Multi-Stream Transport) capability that the Sharp PN-K321 supports to push the screen refresh rate up to 60 Hz.
4K Gaming at 60 Hz using MST
With 4K display technology just emerging in the US this year, this technology is still very new. You can connect 4K displays to a Windows 8 PC over HDMI or DisplayPort, but there are some special considerations if you demand high frame rates. By default displays connected via DisplayPort or HDMI will max out at a 30 Hz refresh rate. This is due to bandwidth limitations inherent with the existing standardized specifications for these display connectivity busses. In order to support a 60 Hz display refresh rate at 4K you need to use more than one stream. When MST is enabled on the Sharp PN-K321, two display surfaces are presented over a single DisplayPort connection. What you end up with is two “portrait mode” displays, one for each half of the physical display. I added a second AMD 7970 card in Crossfire mode just in case additional GPU horsepower was needed for 60 Hz gaming with this setup.
The important thing about MST is that each stream (display seen above) can be driven at higher refresh rates, 60 Hz in this case. By using AMD Eyefinity these two display surfaces can be unified as a single 3,840 x 2,160 virtual display capable of full 60 Hz refresh rate.
Success! Full 4K Ultra HD resolution at 60 Hz
Wow, the textures in the game and the fluid motion at 60 Hz was just astounding. I cranked up all the setttings to “high” and was still pushing ~150fps. I don’t think I needed the second 7970 card, but I had it on hand, so why not?
The following video shows both of these gaming scenarios in action:
Pushing 12K PC Gaming to 60 Hz
Both of the previous scenarios (4K 3×1 at 30 Hz and 4K 1×1 at 60 Hz) were trouble-free and are supported by the AMD graphics drivers and software I had installed. But what I really wanted to experience was a full 3×1 12K panoramic gaming experience at 60 Hz. I called up Jeff at AMD again and he was interested in trying this out since he wasn’t aware of anyone testing this type of setup. The events that would follow would push the limits of everything we had at our disposal. Could it be done? Read on.
In order to test this scenario we would need to leverage MST on the Sharp PN-K321 displays, leverage DisplayPort connectivity for all displays, and use Crossfire to supply enough GPU resources to push 12K resolution at 60 Hz. Sounds like fun to me!
We decided to run the ASUS HD 7970 DirectCU II card as the primary card due to the 4 full-size DisplayPort connectors that it supplied. We added a second AMD 7970 card in Crossfire mode, and went through the process of setting up the MST display groups. This did not work since this configuration hasn’t been tested and is not supported.
Determined to experience 12K 60hz gaming, Jeff asked his team at AMD to produce a custom driver package so that we could test out this extreme 4K MST setup. With only one day remaining with the loaner Sharp PN-K321 displays, we knew we only had one shot at this. We would be stepping into new gaming territory if we succeeded.
Jeff showed up the next morning with a custom driver build, extra GPU hardware, and many power connectors. We were determined to reach our goal. It wasn’t a smooth process, but we were able to get all 6 virtual displays unified as an Eyefinity display group. We fired up Dirt3 and were not hopeful about gameplay because the intro screens were very choppy and slow. “Let’s try the game and see how it goes” we agreed. Gameplay was not good as we were only getting 8fps. We spent a while adjusting graphics settings in the game, but decided that it was not going to work out with the hardware we had. We speculated that adding more GPU capability could potentially get over the threshold that was causing the “thrashing” that resulted in low fps numbers. We decided to add another 7970 card (for 3 total). This would be challenging as our case/motherboard was only setup to accommodate two cards, and we would need to install three cards (two double width, and one triple width). We both took a good look at the two gaming PCs we had on hand and decided that one of them may fit all three cards if we unbolted the power supply and pulled it out to make room for the 3rd card.
**Warning: do not try this at home – replicating this setup could damage hardware and/or void your warranty!
We had to stretch one of our Crossfire bridge connectors a bit, and used every power adapter on hand to get everything connected. Jeff calculated that we had “at least 50 watts of power to spare” out of 750 watts total. Ugly as it was, the machine did boot just fine!
Running completely untested private drivers and bumping up against thermal and power thresholds, we ventured forth towards our goal of 60 Hz 12K gaming.
With all settings on “High” except shadow detail and particles, we were able to maintain 62-67fps average, peaking over 70fps. We were both able to experience this awesome gaming setup for several minutes each before the PSU would reset due to power overload. Perhaps we didn’t have 50 watts to spare. We reached our goal and were able to see into the future of multi-mon gaming. Now that’s a great day at work!
Here are some statistics for this demo:
- GPU cores: 3 x 2,048 = 6,144 total cores
- Rendered pixels per second = 11,520 x 2,160 x 60 Hz = 1,492,992,000
Regrettably I did have to ship back these amazing displays, but I enjoyed the time I had with them in my lab. I have more extreme 4K content related to the PN-K321 coming shortly, so stay tuned!
Find me on twitter here: @GavinGear
Updated November 7, 2014 7:17 pm