Subject: Re: twe status queries?
To: Frank Naumann <>
From: None <>
List: tech-kern
Date: 12/02/2005 12:12:36
In message <>Frank Naumann writes
>> However, I'm seeing a tremendous performance difference between ld0 and
>> ld1.  I have a disk exerciser program; when I run it on ld0, it runs at
>> a particular speed; on ld1 - in the same way - it runs at about 15% of
>> that speed.  Yes, that's 3/20 the speed - almost an order of magnitude.
>> At first I thought it might be that ld0 had priority over ld1, because
>> they were running simultaneously, but when the ld0 run finished, the
>> ld1 run didn't speed up any.
>What exact escalade raid controller do you have? The performance 
>difference is normal for the escalade 7000/8000 series. This is because 
>Raid5 is accelerated by the so called R5 fusion technology on this 
>controller (hardware XOR engine or something like that). The problem is 
>that the escalade 7000/8000 can only accelerate one Raid5 array with this 
>technology (so additional Raid5 arrays are much slower). Btw. this is 
>mentioned in detail somewhere in the escalade users manual.

hi Frank,

I find that a fascinating detail. Do you know of a comparable (12-port
or more) escalde series which can support 12-drive or greater configs,
and which also offers at least one of:

  a) supports 2 or more RAID-5 sets with performance not less
     than the `fast' set of der Mouse's setup (multiple hardware XOR engines,
      or sharing a fater engine amongst multiple RAID sets?); or

  b) Supports single RAID sets larger than 2TB?