Subject: Re: Out to Video
From: Andrew Hofman <[email-masked]>
To: Multiple recipients of list <[email-masked]>
Date: Fri, 15 Dec 1995 17:31:03 -0500

At 11:41 AM 12/15/95 -0500, you wrote:
>
>>And since the PVR has a direct SCSI-2 connection to its drive, it
>>outperforms ANY card that sends video over the system bus, and even the
>>system buses themselves!
>
>
>Actually, I seriously doubt that scsi-2 will outperform PCI.  PCI 64 bit has
>a maximum data transfer rate of 528 MB per second. thats megaBYTES, not bits.
>
>Plain Jane ISA gets about 12 MB per second.
>
>Fast Synchronous transfer mode in scsi2 and 3 at 32 bit is 40 MB per second.
>
>source -Peter Norton's Guide to the PC.
>
>Just so ya know. 
>
>Marcus
> 

I knew I was asking for it when I posted that message. The allowable speed
of the PCI spec is not in dispute, but when you add up all the ACKs and INTs
and other garbage any bus has to deal with, it eats up to a lot of overhead.
That's a pretty huge chunk of the bandwidth pie right there. There is not
yet a card on the market that can do through PCI what the Perception does
through its built-in SCSI-2 port, certainly not with a single drive. Why?
That port has nothing better to do all day than spew video.

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