SATA: RAID 5 controller recommendations

Markus Kovero markus.kovero at
Wed Nov 2 02:36:51 PST 2005

Dell's CERC sata raid thingy works fast for me but when I turn SMP on 
read  performance drops 50%+ (raid1,raid5,raid10 and single volumes).
I don't know if its aac problem or what.
In leenox it works very well though.

Markus Kovero

ray at wrote:

>At 09:17 PM 11/2/2005 +1100, Michael VInce wrote:
>| For SATA I have always been getting the Dell 750s (now 850s) which use 
>| the 'aac'
>| Adaptec AdvancedRAID Controller driver, do 'man aac' for more details.
>| Dell supply them with a 64meg cache and are hardware raid, I have always 
>| just installed FreeBSD on them and only 1 hard drive comes up as RAID 
>| should be.
>| I have only been ordering the machines in dual drive mirror 1 Raid, but 
>| you could get a PowerEdge Tower servers like the 830 which do raid 5, I 
>| never used one though.
>| Alternatively all the Dell SCSI RAID systems have 256megs cache which 
>| use the LSI Logic MegaRAID ( man amr )
>| Stay away from the ultra low end SC1425 systems they have some kind of 
>| software based raid.
>| The thing I have noticed is that if you compare other (often claiming to 
>| be much cheaper) servers from other companies they often really skimp on 
>| their hard drive subsystems with software based stuff claiming its RAID.
>| I used to be anti Dell and build my own U1 servers from case and up and 
>| had a keen interest in cheap RAID technologies but I gave up a little 
>| while ago.
>| I believe Dell are great value when you consider their RAID 
>| implementations and as long as you are happy with Intel chips.
>| Mike
>| Steven Hartland wrote:
>| > Anyone got any SATA RAID 5 controllers they can recommend
>| > 64Bit PCIX.
>| >
>| >    Steve
>Steve - 3ware is very good.
>Mike - I have some benchmarks from a guy using a Dell with a raid and was
>surprised to see how slow they were compared to our other hardware.  I didn't
>run them myself, but the guy is on the list here some place.  I can send you a
>copy of the spreadsheet if you want to look it over.
>freebsd-performance at mailing list
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