> The 8meg VSIMM in the slot closest to the CPUs (seems) to make
> the MBUS run at 40mhz, so the sbus runs at 20mhz.
> 
> If I move the VSIMM to the slot furthest from the CPUs 
> and closest to the front of the system then the MBUS runs
> at 50mhz and the sbus runs at 25mhz.  On systems this 
> slow every little bit helps.
> 
> Surely that was documented somewhere...

There is the "SPARCstation 20 DSIMM/VSIMM Installation Guide" at:

  http://sunsolve.sun.com/data/801/801-6185/pdf/

This mentions that the rear slot is for the 2nd SX and the front one for
the 1st SX.  You need a special adapter to bring the connector for the
2nd slot through one of the rear (SBUS) slots.  Note that you can have
the SX in the front slot and put DSIMM's in the other 7.

J

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