Imagination's GPU Adds DirectX 11

Imagination Technologies’ new DXD GPU doubles the peak per-cluster performance of the earlier BXT design and adds DirectX 11 support. The licensable design does not accelerate ray tracing in its default configuration but otherwise shares most aspects of the DXT GPU the company released earlier this year for gaming-capable mobile devices.

Having supplied GPUs for a few decades, Imagination more recently is known for offering GPU designs for smartphone processors and automotive-cockpit chips. The BXT, however, targeted cloud-gaming servers and PCs; it won customers in China including Innosilicon and Moore Threads. The DXD targets the same types of game-server and PC customers, raising performance and expanding the set of supported games through its DirectX 11 capability.

DirectX is the Microsoft Windows multimedia API covering graphics and other functions. Microsoft announced DirectX 11 in 2008 and the most recent update, DirectX 11.4, in 2014. Since then, DirectX 12 has been the most recent Windows API, providing more-advanced graphics features apt for locally hosted games. New DirectX 11 game titles, however, continue to be released, and their lower graphics complexity is a better fit for server-hosted gaming. Available for license, the DXD and its drivers support the baseline DirectX FL 11_0 API.

Imagination expects 5 nm DXD implementations could operate at 1.7 GHz. Because most Chinese licensees will build their chips at SMIC and employ a less advanced process, a typical implementation will clock slower. The company usually references a 1.0 GHz speed, which also simplifies conversion between throughput and per-cycle rates. Counting fused multiply-adds (FMAs) and multiply-accumulates (MACs) as two operations, per convention, the DXD delivers a maximum of 4.6 FP32 Tflop/s or 18 INT8 TOPs at that clock rate.