A5000: no NVRAM?

[Chris Beauchamp]

The A5000 design incorporates 4 X 100 MBps FC-AL loops.  That is 400 MBps 
aggregate bandwidth.  The current version of the A5000 is configured with 14 
disks.  The current capabilities of the A5000 disk is ~ 10 MBps and the 
potential bandwidth available is ~ 140 MBps (14 X 10).  I have tested the box 
and have seen close to this performance.  If your application can generate the 
demand, the A5000 will deliver the performance.  Conversely, if your application 
is only capable of reading/writing at 10 MBps, then the A5000 will deliver 10 
MBps.  

WRT to write cache, Sun is well aware of the advantages and disadvanatges of 
having a write cache.  As V.Sander mentioned, you have no controller to 
bottleneck your performance. Hence, potential bandwidth and IOPS are achievable 
and have been verified.  A write cache can certainly positively impact an 
application performance.  An A5000 which delivers full potential performance 
(IOPS and bandwidth) with the benefits of a write cache would be pretty cool, 
huh ?  As Forest Gump says, "life is like a box of chocolates, you never know 
what you are going to get ..."

Chris

> Date: Thu, 19 Mar 1998 16:16:39 +0100
> From: zdv123@zam229.zam.kfa-juelich.de (V.Sander)
> To: ssa-managers@Eng.Auburn.EDU
> Subject: Re: A5000: no NVRAM?
> X-Info: To unsubscribe, send 'unsubscribe ssa-managers' to 
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> 
> >> Hello,
> >> 
> >> I can't find anything about NVRAM in connection with the A5000 Array
> >> (e.g. in the Technical White Papers for A5000). Do I miss something?
> 
> >No, you didn't. The A5000 disks are pure fibre channel...there's
> >nothing between the disks and your host...
> 
> 
> Except of an optional Hub, the Interface Board (with firmware on it, but
> no cache) and the backplane. 
> 
> Consequently the single-disk performance of an A5000 disk is the same than
> a single disk performance of modern Fast-SCSI-disks. 
> 
> Volker