> High-performance computing (HPC)

> Data centers

> Big data

Can you give me some specific roles for this range of servers? What makes it's worth compared to x86 system?

The high-end POWER 7/8 hardware has incredible single core performance, beating the pants off Xeon. It uses huge amounts of power to do that, so it's not appropriate for all roles. Low end POWER is pretty niche. Freescale uses the architecture for telecoms applications.

In general Linux upstream these days "just works" on ppc64 & ppc64le. There's RHEL for POWER already, and IBM have loaned hardware to the CentOS project so we'll get CentOS on POWER pretty soon.

The licensing of (Open-)POWER is more open than x86 (but not as open as stuff like RISC-V), and there are several second sources for chips, in situations where that matters.

You get a pretty decent multiple of performance on power vs. intel. Probably something like 4-7x for common use cases.

Generally speaking, you buy the hardware because your workload needs the single core performance, or you're arbitraging vendor licensing costs for software.

Also, IBM's bread and butter is "peaky" financial services and gov't business, so they have business models that makes it work from a $ pov. You can buy a box with 100 cores, pay for 20, and lease 30 more for a few days to meet your peak demands for tax/christmas/billing season.