“Traditionally GPUs are a central block,” said Beets. “What we have done is have GPU cores picking up work autonomously. There is one core in charge, for example using an AXI interrupt line so there is no special signals, no spaghetti logic,” he said.
“Our cores have always had their own firmware processor – you can either have one processor in control or run the cores individually, which might make sense in the data centre market, where the different cores are allocated to other customers. Historically we have used MIPS cores but we are in the process of moving to a RISC-V core on some. All the automotive variants have a full RISC-V processor - the consumer grade are an older instruction set, some are MIPS for highly area focussed designs while the higher performance for the BXT is a variation of META processor but all run the same code,” he said.
Imagination has had a focus on low power graphics suitable for mobile applications, and had deals with ARM and Apple in the past. This low power consumption is increasingly important for data centre chips that have to provide high performance in a rack with a fixed thermal limit.
The growth in streaming games, where the rendering is done in the data centre, is driving the need for higher performance chips. The B-Series also includes IMGIC image compression technology in the market to provide new bandwidth saving options. It offers up to four levels of compression, from pixel-perfect lossless modes to an extreme bandwidth-saving mode, which offers a guaranteed 4:1 or better compression rate. This gives more flexibility for SoC designers to optimise either for performance or to reduce system cost while maintaining a great user experience. IMGIC is compatible with every core across the B-Series range, bringing the benefits of Imagination’s industry-leading