On Tue, 20 May 2003 Yoshiki.Ohshima at acm.org wrote:

>   Oh, do you mean that there are some (stepping of) chips with the
> fixed cache and named PXA250??

The chips with the fixed chips are the PXA255, IIRC.  The 255 actually
isn't much different from the 250, from what I've heard, it is technically
a revision of the 250 rather than something meriting a new
chip-designation.  I'm not sure what this really means, but that's been
the word on the street.

>   As for the Squeak performance, there is another twist in this story.
> The VM on SL-C700 (a PXA 250 device) feels much faster than other PXA
> 250 based WinCEs (Aaron has reported similar with his machines...)
> There might be some performance glitch in the VM support code.  The
> toolchain that Sharp provide is based on 2.95.2 and I don't think it
> does XScale specific optimization.  If we change the compiler, it may
> get some boost.

In my case, I found that the 206 MHz StrongARM'd Zaurus SL-5500 was about
20% faster (using #tinyBenchmarks, and considerably faster "feeling") in
Squeak than the WinCE-based iPAQ 3100 and Jornada 720 I also use with
Squeak, both with the same 206 MHz StrongARM.  I found out from where this
performance boost was coming- the Zaurus SL-5500 has a 100 MHz bus, where
as the iPAQ 3100 has a bus in the area of 30 MHz or so, and the Jornada
720 has a 50 MHz bus.  Linux + Squeak on an iPAQ performs about the same
as WinCE + Squeak on the same iPAQ.

I've not owned a C700, though, although donations for the development of
Dynapad would always be accepted. ;)  The C750 and C760, with its PXA255
should make a really awesome Squeak machine.

Yoshiki-san: I won't be able to try out that Squeak for Qtopia- I sold my
Zaurus SL-5500.  Great for running Squeak, but poor-ish hardware and poor
software for the most part.  Running Squeak on my Axim overclocked to 400
MHz, or on my Jornada 720 overclocked to 221 MHz makes up for a healthy
amount of the speed difference between the SL-5500 and other machines with
the same CPU.


Regards,
Aaron

  Aaron Reichow  ::  UMD ACM Pres  ::  http://www.d.umn.edu/~reic0024/
  "A weed is just a plant whose virtures have not
                     yet been discovered."            :: r. w. emerson