Re: IBM PPC750L vs Motorola MPC7410

[Paul Mackerras <paulus@samba.org>]

Peter Dennett writes:

> Is there someone on this list that can be so kind as to give
> me a technical summary of the differences between the
> PPC750L (G3) and Motorola MPC7410 (G4) so far as
> LINUX operation.

The biggest difference is that the 7410 has Altivec and the 750
doesn't.  Altivec is an extension to the instruction set that adds 32
128-bit registers plus a set of SIMD-style operations on those
registers.

Beyond that there will be differences in the special-purpose registers
(SPRs) accessible in kernel mode.  I don't think there would be
enormous difference but there would be some.

The kernel should detect which CPU you have and do the right thing
automatically.  Neither chip has an on-chip memory controller or
serial port; both have on-chip L1 I and D cache and on-chip L2 cache
controller and tag RAM (if I recall correctly).  So I don't know why
the kernel would hang when booting the G3.

Paul.


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