HPC won't be x86 forever - and it's starting to show

"Supercomputing development has evolved in waves since Cray pioneered vector processors (which were excellent at conducting single operations across large data sets) in the mid-1970s. Later came reduced instruction set chip (RISC) architectures with chips like the 64-bit DEC Alpha, IBM POWER, Sun/Fujitsu SPARC, SGI MIPS, and HP PA-RISC. Each offered distinct performance characteristics. Their simpler instruction sets made for fast instruction decoding and pipelining, and also served more general-purpose use cases than vector-based systems."

"The coming of the commodity cluster The problem for RISC was economic. Chips manufactured in smaller volumes cost far more than commodity chips like x86. NASA realized this and began using Intel chips for its Beowulf supercomputing clusters as far back as 1994. It proved that running cheap chips in parallel could approach or match specialized hardware in performance terms while slashing costs."

"Remember when high-performance computing always seemed to be about x86? Exactly a decade ago, almost nine in ten supercomputers in the TOP500 (a list of the beefiest machines maintained twice yearly by academics) were Intel-based. Today, it's down to 57 percent. Intel might once have ruled the HPC roost but its influence is waning. Today, other processors are making significant inroads."

High-performance computing moved from vector processors to RISC architectures and then toward commodity x86 clusters. Cray's vector machines excelled at single-operation work across large datasets in the 1970s. RISC chips such as DEC Alpha, IBM POWER, SPARC, SGI MIPS, and HP PA-RISC offered simpler instruction sets that favored fast decoding, pipelining, and general-purpose workloads. Economic pressures favored high-volume commodity x86 chips, leading to Beowulf clusters and Intel's ASCI Red achieving teraFLOPS with many Pentium Pro processors. GPUs gained prominence after Nvidia's 2006 CUDA, enabling dramatic parallel speedups. AI and hyperscale growth are expanding architecture choices beyond x86, with accelerators drawing major market attention.

Read at Theregister