[tgflynn]

I don't think there's much competition between x86 and s390. You'll use the later only if you're already an IBM mainframe customer and don't plan to migrate off.

For Power vs x86 it probably matters a lot what type and scale of operations you're at. As far as I can tell x86 typically has the better price/performance ratio but then I think there are quite a few supercomputers that use Power so there must be some advantages (probably mostly I/O related).

[CyberFonic]

The only Power based supercomputers I can think of are all from IBM. Does any other vendor use them?

Power CPUs tend to power either iSeries (latest iteration of AS/400 - System38 etc) systems or AIX based. The large AIX systems use lots of CPUs, cores and typically vPars - but I wouldn't call them supercomputers. Disk I/O is generally FC attached SAN, i.e. performance is achieved through off-loading. A typical SAN array contains gigabytes of caching memory, CPUs on each disk drive with yet more RAM and multiple optical FC links to each node.

[tgflynn]

> The only Power based supercomputers I can think of are all from IBM. Does any other vendor use them?

Perhaps not but there are non-IBM Power systems available, such as those from Raptor, as well as IBM Power systems primarily intended to run Linux.

Also I think Google has looked into running Power systems, but I don't know that they have any in production.

[mikewang]

I tried to google it. And two passages. The common point is "high-efficiency, built-in virtualization solution, as well as its ability to support massive enterprise-class workloads without requiring the type of massive infrastructure that you would need to do the same using x86 chips"

Power supports virtualization from chip level which looks excellent. But heard little that company would like to transfer to power from x86.

[tgflynn]

That sounds more like marketing hype than anything else. Intel chips also support virtualization that is far more widely used (basically all the cloud providers - AWS, Google, Azure, etc.). As for lower infrastructure costs, I have trouble believing that. If you look up the specs on Power chips you'll find that they're aptly named, they're power hungry beasts.