Instead of using an entirely new GPU, Cerny said the PS4 Pro is using a "double-sauced one." In effect, the new console has a second, identical GPU configured next to the original, more than doubling the processing power of the Pro. While the standard PS4 produces 1.8 teraflops, the PS4 Pro achieves 4.2 teraflops. This is how the device can achieve native 4K and, in some cases, what Cerny said are results "extremely close to 4K." For select software, including games like adventure title Horizon Zero Dawn and Call of Duty: Infinite Warfare, the PS4 Pro will use a crafty technique called checkerboard rendering to achieve 2160p resolution. Checkboard rendering changes the formation of pixels to achieve higher-fidelity graphics.
Standard PS4 games will play just the same unless devs patch them
For the more than 700 or so existing PS4 games, Cerny said the goal was to ensure those titles played smoothly no matter what. That's why the Pro incorporates an identical GPU. Because the new console has "the old GPU next to a mirror version of itself," Sony can support existing games with a simple trick: "We just turn off the second GPU," he said. Developers can patch these titles to boost graphics and performance in very subtle ways. But unless you have a 4K television, the difference will not be substantial.
Sony says it doesn't want games released solely for the PS4 Pro
When asked whether Sony would ever let a game run exclusively on the PS4 Pro, Cerny was blunt. "We're putting a very high premium on not splitting the user base in that fashion," he said. That doesn't rule out the possibility that, two or even three years down the line, a game comes out that relies so heavily on the hardware improvements of the Pro that it becomes unplayable on the standard PS4. Cerny wouldn't really speak much to that scenario, saying that Sony is asking developers to take advantage of the new console without leaving older hardware behind. You can also watch Mark Cerny chat with PlayStation Blog's Sid Shuman about the creation of the PS4 Pro here on YouTube.