[klauspost]

Reading it, it seems very similar to the Playstation 3 Cell, with its fate mirroring it very much.

A highly specialized processor that has very high computational throughput for specialized operations, but a quite limited scalar unit.

In both cases you really have to write software specifically for it to get it to perform with any reasonable speed. If you do that, you get great value, but any existing code will need significant modifications to perform.

Granted AVX512 is (now) more common than SPE code ever became. It is slightly better than the Itanium approach, but scalar performance (especially single threaded) will have limited the value you get from this CPU, unless you write your own software and it can utilize AVX-512.

[rbanffy]

It was much easier to program though. The Cell had two different ISAs, one for the PPUs and one for the SPUs. The SPUs also didn't have direct access to memory and the PPUs had to manage task assignment and completion, as well as setting up DMA transfers between SPU memory and main memory.

The Phi was closer to the Sun Niagara family - lots and lots of simple, slow, cores, with the note that, in the case of the Phi, the weakling x86's had mighty SIMD abilities while the Niagara had more or less standard SPARC stuff.

Neither will have amazing performance unless you have at least as many threads running as you have cores, and most of the time, at least twice as many. For single-threaded code, they were on the slow side.

Still, I always suggested people use Phis to develop because they'd get a taste of future computers. Nowadays a decent laptop will have half a dozen cores and, unless your mail client has that many threads, it'll not feel as fast as it could be.