On 2020-07-24 03:16, Kihaguru Gathura wrote:
Hi,
Which of the following legacy CPU types is best suited for very busy web
server httpd+slowcgi
Niagara CPU Such as T2 - More parallel Threads and Low power per single
thread
Sparc64 CPU such as VI, VII - Fewer threads but more computing power per
thread.
How is multithreading utilization of httpd+slowcgi like?
Kind regards,
Kihaguru.
Hi Kihaguru,
As with any computer, newer tends to be better with Moore's Law and all
that. On sparc64 most of the logical cores that are shown are really
just SMT pretending to be a bunch of cores. I have one machine that
claims 128 cores, but in reality, its just 16 cores with 8-way SMT.
sparc64 isn't renowned for its single core execution speed, so the
faster the better in that regard.
In my experience with running OpenBSD on sparc64, the kernel biglock or
crypto became a bottleneck before other things did. (I've used T3 and T4
machines fairly extensively with OpenBSD). I've found that disk
activity, networking and/or TLS would bottleneck before httpd became a
bottleneck when I was running sparc64 web servers in production. If you
are running very heavy scripts/programs with slowcgi, then you're
results may be different.
Things have likely improved dramatically in the past year or two with
all the work done on removing the biglock, but the moral of the story
remains, fewer, faster cores are likely to produce superior performance
to numerous low power cores.
Regards,
Jordan
