Triple Monitor 4K: Gaming at 1.5 Billion Pixels Per Second

By Wesley Fenlon

Microsoft puts some loaner 4K monitors and beefy AMD graphics cards to great use.

While most of us are tantalized by the thought (and horrified by the expense) of gaming on a 4K monitor, Microsoft's Extreme Windows Blog has been dreaming bigger. Who would want to play on one 4K monitor when the option exists to play on three of them? As if that weren't taxing enough, the blog set out to do a triple monitor setup at 60Hz, rather than the far easier 30Hz.

Spoiler: They succeeded, but the hardware it took to run games at that resolution is the interesting part. It started with three 4K Sharp panels running at a combined resolution of 11,520x2160. They fed the displays video from an ASUS AMD HD 7970 DirectCU II card, which features four DisplayPort connections and 3GB of GDDR5. That card, by itself, was just barely up to the task of delivering 30 frames per second in Dirt3 at high settings.

But that wasn't enough. 30Hz is too easy, and too slow, so they shot for a 60Hz refresh rate. Getting 60Hz out of DispalyPort for a single 4K display meant turning on Multi-Stream Transport and using AMD's Eyefinity to essentially combine two "virtual" portrait mode 1920x2160 displays into one unified display.

Adding in another AMD 7970 actually delivered about 150 fps in Dirt3--but only on a single monitor. Pushing 60Hz on all three 4K monitors turned out to be an even bigger challenge. For starters, there were no drivers that supported a Crossfire 7970 4K setup. Since AMD was collaborating on the project, they whipped up a custom driver.

And it worked, but at about eight frames per second. Adding a third 7970 brought the game up to an amazing 60+ frames per second. For about five minutes at a time, anyway, since the whole thing would overheat and shut down after that short a time. After all that setup, it was the 750 watt power supply that let them down.

In total, the three video cards were pushing almost 1.5 billion pixels (1,492,992,000) per second. How long until we'll be able to do that with a single graphics card?