>>  1268 at 927  (just what it happened to be)
>
> Display depth? Host display depth?
>
> Make sure both match. Setting both to 16 might help, it's half the
> data. Both at 32 might or might not be faster. On Intel, using an LSB
> display might help (see appearance - display depth).

Thank you, Bert - that was the problem.

I run Squeak with 32-bit colour, but on the suspiciously slow Toshiba the
Windows setting was 16 bits.  Changing Windows to 32-bit colour won a
factor of five speed-up (I wonder why five?).

Very happy.  I had wanted to buy that model of laptop anyway, but couldn't
do so while Squeak performance seemed so poor...

Best wishes -

Aran