Very low disk performance Highpoint 1820a

[willem jan withagen]

Steven Hartland wrote:
> If that where the case it would have been it wouldn't have been
> 46Mb/s it would have been 543Mb/s, just tested it for you :P
>>> I've just finished putting together a new server box spec:
>>> Dual AMD 244, 2GB ram, 5 * Seagate SATA 400GB on a
>>> Highpoint 1820a RAID 5 array.
>>
>>
>>> 5.4-STABLE Highpoint 1820a RAID 5 ( 5 disk )
>>> 655360000 bytes transferred in 13.348032 secs (49097875 bytes/sec)
>>
>> You're only transfering 640M in 2GB of RAM, big chance that you're 
>> testing memory/buffercode-speed in stead of testing diskspeed.

Still I would argue that if you do not use a write size larger than what 
you have as real memory, that buffering in real memory is going to play 
a role....

Other than that I find 50Mb/s is IMHO reasonable high value for a RAID5 
in writting. But it would require substantial more organised testing. DD 
is nothing more than a very crude indication of what to expect in real life.

--WjW