Any way to dedicate memory?

[Peter Seebach <seebs%solon.com@localhost>]

I'm looking at putting a SCSI/RAM card in my A4000.  Is there any
way to dedicate the memory on such a thing to 2ndary activities,
like disk buffers, or otherwise isolate it from main memory, to
avoid the performance hit it gives?

It would be wonderful to have a couple megabytes of disk buffer
even if they're slower than main memory, and free the normal
buffers up for normal use.  It would be irritating, and possibly
counterproductive, to have slower memory mixed in to the main pool.

-s