On Mon, Oct 29, 2018 at 1:33 PM Rick Stevens <ricks(a)alldigital.com> wrote:
Do big IBM (or any) mainframes still exist?
You can still buy S/390's, but the big money is not in mainframes, but in
supercomputers. It used to be (in the days of Seymour Cray) that a
supercomputer just had a really fast processor that could do vector
processing (running the same instruction on a whole block of memory
locations in parallel in a single clock tick), but we have pretty much
gotten to light speed limitations on how fast a processor can be, so IBM's
supercomputers these days are clusters of thousands of processors and
cores, exchanging data over specialized high-speed fabrics such as
Infiniband. Linux is critical to making this work (as well as specialized
application libraries to support interprocess communication on such as
system). The IBM supercomputers I have seen all use a variant of Red Hat
Linux, so I wouldn't be surprised if acquiring Linux developers might not
be the main reason for IBM to want to buy Red Hat.
--Greg