Subject: Re: presto support?
To: None <>
From: Matthew Jacob <>
List: port-pmax
Date: 02/11/1998 14:36:34
>Right.   And the effect isn't the same - in one case, you're getting
>speed and reliability.   In the other case, you're only getting speed.
>BTW, if the PrestoServe support was implemented the right way, it
>would speed up local as well as remote disk access.

Yes, this is true. But also note that PrestoServe memory cards
are slave only devices. Assuming a TurboChannel or SBus or PCI
memory card you're stashing data in you pay for not only the
CPU cycles of moving the data, but moving it in a really undesirable
manner (across several bus bridges, little help from a cache
prefetch, and also providing massive interference for other I/O
that may be occurring). The tradeoffs are not always obvious.