Addonics Controller – 3 Disk RAID 5
RAID 5 can be problematic for RAID controllers, as it often requires that the RAID controller read the disks before it writes updates. This can make RAID 5 quite slow, if the controller does not cache writes.
Theoretically a perfect 3 disk RAID 5 set would provide 2x - 2.5x the (read) throughput of a single disk, and depending on the number of requests outstanding, anywhere from the same latency to half that of the single disk. Again, nothing is perfect and the Addonics RAID controller has the disadvantage of having no write cache.
Let’s see what ATTO makes of our three disk RAID 5 set:
The ATTO result for the 3 disk RAID 5 set are astonishing. The read and write performance matches that of the 2 disk RAID 0 - we're not seeing the expected RAID 5 write penalty.
HDTach shows a similar result. Compared to the single disk environment, throughput is up across the board, but the latency is unchanged, and we've achieved the extra performance without risking data loss from a drive failure.
HDTune shows us more of the same – but with a small twist. Firstly, random IO is slightly degraded with the RAID 5 set:
HD Tune has measured an increase in latency of about 16-20%. Not a bad result, but it could be better and performance does drop as a result. The key seems to be a number of significantly longer latencies (the yellow dots at the very top of the sequential graph below. There's no obvious cause for this that we could find.
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|70.114.239.xxx |2009-12-30 06:46:59 outcast2k - product review gaps?good start on covering some of the basics. some other detais that would be good to know:
1) how long does a RAID rebuild take?
2) how do you tell how far a rebuild has left?
3) how do you tell which disk failed?
4) does the software UI handle 2+ HDM-XA's in the system?
5) how do you recover the RAID if the HDM-XA itself has failed and needs to be replaced?
6) what's the biggest sized drives supported? 2TB?
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|219.90.134.xxx |2010-03-07 23:17:32 TERRABYTEONE - ?? 3132 pciex1 card max output is 190mb/seciv tested this.. etc..
sil 3132 pci-e x1 card )(addtronics one) or jmb 363 or highpoint 4 port x1 2300 raid card.
max oot put is 190mb sec total.. and if using 2 ports its 95mb/sec..
tested this using 4x volir wd 300g hdd
(they get each 109mb/sec)
so if using both e-sata ports.. transfer maxes out at 190mb.sec..
if using 4 hdd in raid 0 etc... max output for 4x vr 300 on intel on-board raid (x48 chipset) 500+mb/sec..
on sil using this product is.. 90mb/sec.
als tryed 4x 1.5 tb 7200.11 hdd..max out at 90mb/sec
also tryed raid 5.. 90mb/sec.
2tb hdd supported. but hardware or nonhardware raid the sil raid gear does not support partitions bigger than 2tb.(old design)
to get 6 tb hdd spac out of in i raid 0 (4x 1.5tb)
i hd to make 4 partitions .. the software is limited in what size to make. it..it was tricky.. i had to make partitin/volumns 2+ then delet and recreat smaller ones. in aparticular order.
they need to update thar raid cards. (chan...
Thanks for the great write up!