Today, Imagination Technologies announced its new top of the line mobile GPU and successor to the PowerVR GX6650, the PowerVR GT7900.
The new GPU comes with 2.6x more ALUs than the GX6650, which is 512 "cores" in total, combined in 16 Unified Shader Clusters. The GX6650 had only 192 ALUs and six clusters. This will give the GT7900 more than triple the performance of the GX6650.
Imagination expects the higher performance to be kept in check by the transition to the newer 14nm and 16nm FinFET process nodes later this year. Also, this new GPU is mainly targeted at inexpensive mini-consoles (such as Android TVs), which could afford extra cooling compared to a mobile phone or tablet.
The PowerVR GT7900 aims to bring "PC-class" gaming with powerful hardware and support for the OpenGL ES 3.1 graphics API and the Android Expansion Pack (geometry shaders, tessellation, ASTC LDR and HDR texture compression standards, and so on).
Imagination also added hardware virtualization inside the GT7900 GPU so it can support multiple operating systems without a drastic hit in performance. This feature could be especially useful for enterprise customers who want to keep personal environments separated from work environments, even on mobile devices. The feature can be found in Imagination's MIPS Warrior CPU, as well.
Even though most CPU or GPU designers these days focus on "burst" or "turbo" speeds that win popular mobile benchmarks, which run for only a few minutes, which isn't enough time to really heat up the device, Imagination seems to remain focused on sustained performance. Fortunately, when it comes to gaming, sustained performance is really all that matters. If a GPU or CPU can only run at its full advertised speed for 5-10 minutes, and then its performance drops by half in order to keep the device's internals from melting down, that doesn't provide a very good user experience.
A new feature that came with the Rogue architecture is PowerGearing. This is a saving mechanism that automatically shuts off parts of the GPU in power-constrained applications. In other words, the GPU's performance will only be activated as needed, rather than the whole GPU being fully activated at all times and consuming more power.
Just like Nvidia's Tegra X1, Imagination brings a bigger focus on the high-performance/low-power FP16 mode that can reach up to 1.6 TFLOPS. The GT7900 GPU can reach 800 GFLOPS in the FP32 mode.
All the new GPUs being announced right now will feature (true) 4k support, and the PowerVR GT7900 is not missing this feature either. In fact, the GT7900 is the second PowerVR generation to support 10-bit YUV color support, which is an essential part of the UHD/4k standard. Imagination's new GPU can also easily handle 4k video playback at a smooth 60 fps.
Imagination also offered a sneak peek at the Dwarf Hall console demo, which is to be fully unveiled at GDC this year. Some of the effects in the Dwarf Hall demo include:
1 million triangles per frame in some scenesDeferred shading with 128-bit physically-based G-bufferMany dynamic lightsMultiple specular probes treated as lightsSoft particlesLens flare effectsFull post-process pipeline with color correction, saturation, dynamic exposure and HDR tonemapping
System makers interested in building an affordable console with PC-class gaming and true 4k video playback support could buy the full SoC solution from Imagination, which includes:
a main dual-threaded processor quad-core I6400 MIPS CPU that's organized in two clusters and supports Android 5.0 Lollipopthe new PowerVR GT7900 GPU PowerVR Series5 video encode and decode processors (VPU)PowerVR V2500 camera processor (ISP)Hi-Fi audio microcontrolleran Ensigma radio processor which includes 2x2 MIMO 802.11ac Wi-Fi, Bluetooth 4.0 (and Bluetooth Smart/LE) and digital radio Ensigma security module other components as needed
Imagination is advertising its new PowerVR GT7900 GPU for the 14/16nm FinFET process nodes, which will only be available later this year. That means products that will include the GT7900 will only begin shipping late this year. More information will be revealed at MWC next week.