Re: New to DragonFly...

["Dmitri Nikulin" <dnikulin@xxxxxxxxx>]

On 4/27/06, Jonas Sundström <jonas@xxxxxxxxxx> wrote:
> "Dmitri Nikulin" <dnikulin@xxxxxxxxx> wrote:
>  ...
> > Worthy archs are Alpha, Sparc (32 and 64), AMD64, i386,
> > PowerPC, POWER5, IA64. The rest is not very useful.
> > Am I missing one? Can you SMP ARM or MIPS?
>
> I believe these duals (and the quads too?) are used in Cisco systems:
> http://www.broadcom.com/products/Data-Telecom-Networks/Communications-Processors
>
> NetBSD's sbmips port targets Broadcom's dualcore evaluation board.
>
> Cavium seem to be offering some interesting multicore chips:
> http://www.cavium.com/newsevents_OCTEONMIPS64.html

That's impressive, but how well would a 16-core CPU scale in terms of
bus and memory utilization anyway? The value of packing more cores in
runs thin pretty quickly, especially without sophisticated
interconnects like HyperTransport and the AMD64 on-CPU memory
controller. So you pay exponentially more for only a logarithmically
higher throughput, with potential *losses* due to kernel SMP
scalability (which is still a major problem in NetBSD's SMP). Unless
I'm really missing something about their architecture.

  -- Dmitri Nikulin