🚀 go-pugleaf

>                  ...what would happen if you actually installed such
> hardware?  Would the NFS software support it or would you then have to
> make major modifications to the system software before you would
> benefit from purchasing the hardware?  If you actually used such
> hardware, would you notice a degradation in throughput to the disk or
> does the DES hardware run DMA in parallel with the cpu and i/o
> controllers?

No, NFS does not currently support the use of DES (chips or software).
This is because there are lots of things that Sun has on its list to
do, and supporting chips that the government won't let it sell is pretty
low on the list.

The chips are run as programmed-I/O devices.  They do not have any DMA
control.  The chip involved requires really wierd timing just for programmed
I/O, and a 68020 running a tight loop is a pretty good DMA controller.
The time required to encrypt and decrypt, whether with a DMA controller
or not, would be added to the wall clock time already required to service
an NFS request.  I suspect that the effect would be noticeable, considering
that turning off UDP checksums makes a measurable difference.

Bob Smith of Sun testified yesterday for US Representatives Norman
Mineta and Don Edwards that Pentagon export regulations are big problem in
keeping Sun competitive in the world market: "In many respects, the
Departments of Defense and Commerce are in the Dark Ages of computer
technology".  Smith acknowledged some recent improvement in the
commerce department but he added that "our fear is that computer
technology is moving faster" than government's ability to keep track.
(SF Chronicle, April 17, pg. 36)
-- 
Copyright 1987 John Gilmore; you can redistribute only if your recipients can.
(This is an effort to bend Stargate to work with Usenet, not against it.)
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