RAID5 vs RAID10 speed
 

I migrated my array from RAID10 to RAID5, and ran HD tach on each...

RAID10: Average read 93.6MB/s, burst 214.7MB/s
RAID5: Average read 163.0MB/s, burst 1143.3MB/s

I'm sceptical of the burst speed for RAID5. Can the data/RAM bus even transfer data at 1143 megs per sec?

I also expected average read for RAID5 would be similar, or perhaps even worse than RAID10.

My comp just rebooted, now I remember why I changed from RAID5 to RAID10 all those months ago. The array is now rebuilding parity which means I have a slow as shit computer for the next 6 hours! If it reboots again then it's possible I'll lose the array.

Intel's RAID5 driver seems to be buggy as hell; never had a single problem on RAID10.

I guess I'll be reinstalling Windows today, the RAID10-RAID5 migration feature is one way only...

Is this like that teaspoon/tablespoon question that fucked me up on "Are you smarter than a 5th grader?" last night?

I rambled on a bit but basically I'm asking if those figures are plausible. :) I guess it doesn't really matter since the array will be back to RAID10 later today. :)

bump5678

Doesn't really matter.... no frequently accessed file is that big anyways. Look in your manual or on Google for stats on your hardware. I'm sure something else is the bottleneck anyways.

Also, don't forget that those are optimal figures. Sure, usb2.0 is supposed to do 480mbps, but it doesn't do it for very long.

I ended up having to reinstall Windows twice, realising at the worst possible time that I hadn't backed up the system state. All the executable and config files for my applications have been restored, but Windows itself doesn't know they exist. I've now restored my data only, time to manually reinstall 30 applications.....

I do video capturing and also work with some pretty large image files (sometimes several hundred megs in size)

HD Tach measures the speed, so those numbers are what it has reported - it's not merely a spec...

1143 megabytes per sec is over 9 gigabits per second...

Interesting that this is apparently achievable when the drives are gen 1 (1.5Gbps), so the total maximum theoretical throughput of 4 drives is only 6Gbps. :Graucho

What type of drives were they, ide, scsi, SATA 150 , SATA 3.0 or SAS?

Also, what RAID controller?

Brad

SATA gen 1, Intel RAID (software) running under XP :helpme

That's pretty much why I doubted the figures were true... plus the fact that the bandwidth of the 4 SATA 1 channels don't add up to what HD Tach was reporting...