quad processors

[Gilles Gravier]

Hi!

drew einhorn wrote:
>
>
> On Fri, Jan 2, 2009 at 11:01 AM, Gilles Gravier <gilles at gravier.org
> <mailto:gilles at gravier.org>> wrote:
>
>     Want to have even more fun? Run it on a Sun UltraSPARC T2 machine
>     with 2
>     processors... At 64 threads per CPU, the machine thinks there are 128
>     distinct processors... and uses them all! :)
>
>
> Just curious, are there issues with bottlenecks between the processor
> and memory
> with 64 threads per cpu?
>
The machine is designed to avoid that. CPU thread optimization
(re)schedules threads so that they are interlaced, in particular when it
comes to memory access...

Have a look at this blog entry from one of my colleagues :
http://blogs.sun.com/travi/entry/ultrasparc_t1_utilization_explained

Oh... and the cool thing... the UltraSPARC T1 and T2 processors are open
sourced! They are GPL and available in VSDL at :
http://www.opensparc.net/ (anybody here want to build their own CPU - or
want to prepare a CPU design class using an open source CPU?).

Gilles.