[rescue] Sun E4K CPU Upgrade

[Jonathan Katz]

You can mix/match CPUs and it will always clock at the lower CPU frequency
to maintain compatibility, IIRC.

There were so many 400Mhz P/Ns because of ecache parity issues and
manufacturing issues. Some came from TI, some came from Sony, etc. Some had
different cache sizes, IIRC, and some had mirrored cache(!) (later editions
of the 400 and 440Mhz.)

The difference between xx00 and x500 was the backplane speed, and then the
CPU and IO boards had different revs to match the backplane. If you have an
older IO or CPU board, it will dumb-down to the slowest clock speed so the
system can run.

On Wed, Jun 27, 2018 at 7:51 AM, Richard <ejb at trick-1.net> wrote:

> Thanks Peter
>
> So based on the following I think it is safe to say its a 4000. And if I
> understand what you are saying if I put 400Mhz CPU in then all I am going
> to get is 336Mhz any way so probably no point in up reving the existing
> CPU. Probably not supported (probably not an issue for a hobby machine)
> but can you mix 336Mhz and 400Mhz CPU in the same chasis
>
> 8-slot Sun Enterprise 4000/5000, No Keyboard
> OpenBoot 3.2.29, 9216 MB memory installed, Serial
>
> 0,0>    CPU Module Status
> 0,0>-----------------------------------------------------------------
> 0,0> MID  OK  Cache  Speed   Version
> 0,0>-----------------------------------------------------------------
> 0,0>  0 | y | 4096  |  336  | 00170011.20000507
> 0,0>  1 | y | 4096  |  336  | 00170011.20000507
> 0,0>  4 | y | 4096  |  336  | 00170011.20000507
> 0,0>  5 | y | 4096  |  336  | 00170011.20000507
> 0,0>  8 | y | 4096  |  336  | 00170011.20000507
> 0,0>  9 | y | 4096  |  336  | 00170011.20000507
> 0,0>-----------------------------------------------------------------
> 0,0>System Frequency (MHz),fcpu=336, fmod=168, fsys=84, fgen=336
>
> and also that it is running at 336Mhz according to the System Frequecny
> and an 83Mhz Gigaplane (is that the fsys number rounded up?)
>
> Regards