Next, we're going to take a look at graphics performance. Since Fraps (or something like it) isn't available to track frame rates during actual gameplay, we have to rely on a handful of 3D graphics benchmarks. The first of these is GLBenchmark 2.1, which uses OpenGL ES 2.0 and is available for both Android and iOS. GLBenchmark isn't available through the Amazon Appstore, forcing the Kindle out of the action for another round.
GLBenchmark's standard tests measure frame rates as the scene is drawn on the screen. This mode constantly invokes vsync (which can't be disabled) on the Transformer Prime, so we've also tested with GLBenchmark's offscreen mode. Those tests are run at 1280x720 but aren't shown on the screen, preventing vsync from artificially limiting the performance of the graphics processor.
In the Egypt and Pro scenes, the Transformer Prime is handily beaten by the iPad 2. The results aren't even close when we look at the offscreen scores, which give the Apple tablet a commanding lead. That said, the Prime is a huge upgrade in performance over the old Transformer and the Galaxy Tab. Clearly, the Tegra 3 has much more graphics horsepower than its predecessor. Switching the Transformer Prime into power-saving mode doesn't slow the chip's integrated GPU much, either.
We've been having problems getting the full version of RightWare's Basemark ES 2.0 graphics benchmark running on our Transformer tablets, so we had to resort to the free version of the app, which contains only the Taiji test. Unfortunately, the free version isn't yet available on iOS, so the iPad will have to join the Kindle on the sidelines.
The Taiji test confirms that the Tegra 3 has much more potent graphics hardware than the last generation of the chip. Turns out Nvidia's claim of a threefold increase in graphics performance is right on the mark, at least in this scene. Once again, we see very little difference in graphics performance between the Prime's various configurations. I suspect the integrated GPU is being kept at close to full capacity in power-saving mode to ensure that the CPU isn't disturbed for HD video.