Changing my RAID for better performance – A question

[Angelo Lorenzo]

1) Not usually, although any difference in performance speed may lead to uneven read speeds as bytes are read from a slower drive vs a faster drive.

2) Depends on the configuration, number of drives you end up with, the interface card and the connection used to your card/motherboard.

3) RAID 3 is not used much in practice, I suggest RAID 5 https://en.wikipedia.org/wiki/RAID#RAID_5 beneath this is a chart to calculate usable RAID size and read/write performance

60 FPS h.264 footage doesn’t really spark a concern with me in terms of hard drive speed; some other issue/bottleneck may be afoot. Have you looked at Task Manager’s performance monitors when playing back footage to see what spikes?

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Angelo Lorenzo

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[Tim Jones]

1. The new drives will NOT be the same brand as the current ones. They will be Segate drives with the same specs. Is this an issue? Here is the part number, etc:
Seagate Barracuda 3TB 3.5″ SATA3 64MB Cache OEM Hard Drive (ST3000DM001)

They will work, the system should resolve any minor size differences when you re-stripe them.

2. What speed boost can I expect?

You should see the speed of this type of configuration boost by the number of spindles, so 4 drives should give you approximately 4x the speed of one drive (or basically double what you’re seeing now)

3. If I bought a 3rd drive – to make 5 in all, should I do a RAID 3 for redundancy and protection.

You should never do RAID 3 for anything (that was only useful for older, very slow drives), but setting them up as RAID 5 would offer a single drive failure protection level that you don’t get with striping.

With a 4 drive stripe on Windows 7 (Seagate Constellation 3 drives), I’m readily seeing 500MB/sec write and 550MB/sec read with media files. For even more fun, I’ve striped 6 512GB OCZ Vertex 450 SSDs and that is delivering 1.6GB/sec read and write 🙂 .

Tim
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Tim Jones
CTO – TOLIS Group, Inc.
https://www.productionbackup.com
BRU … because it’s the RESTORE that matters!

[Darren Kelly]

I did add the additional 2 drives to make a 4drive, 12TB RAID (Formats to 10.9 TB)

Doing the Decklink speed test, I recorded the following results.

2 Drive RAID

Write: 270mbs
Read: 285 mbs

4 drive RAID
Write: 485mbs
Read: 585 mbs.

The benchmark testing showed things to be slower, which doesn’t make much sense. I may have done it wrong.

The next question?

Will an independent RAID controller make a difference?

Will moving to a RAID 5 by adding an additional drive give me the protection that 12TB require?

WOW the performance of those SSD’s are making me jealous. How many streams can you playback in real time on the timeline?

Do you use windows to RAID, or a hardware raid card?

D

[Tim Jones]

I believe that what you’re seeing for 4 drives is about right. Like I said, it’s “approximately” 4x the performance of a single spindle. There is a bit of overhead to slice and dice the data between the drives.

Unless you’re also planning on moving to some serious number of drives (more than 6 or 8), a dedicated RAID card won’t really boost performance in RAID 0 (striped) mode on newer processors. However, for RAID 5, you’ll need to move to a dedicated HBA since the Windows software RAID options don’t include proper levels beyond concatenation, striping, and mirroring (JBOD, RAID-0, and RAID-1). I really prefer ATTO’s ExpressSAS R680 to the other brands that we tested.

As for protection, while RAID 5 will help if one drive fails (and only if you’re paying attention and replace the failed drive immediately), you should NEVER consider RAID a replacement for backup.

Of course, I’m spoiled since I work with LTO tape all of the time, so my ArGest SSD20 Cube has an LTO-6 drive for backup and long-term archival (of course, I use BRU, but there are other solutions for Windows) in addition to the SSD drives.

For my personal Windows 7 PC, I use the ATTO ExpressSAS H680 and use Windows dynamic volumes in striped mode for the disks. As an aside, I was using a generic Adaptec SAS HBA, but the move to ATTO has improved stability and throughput to both the SSDs and the tape.

This setup works great for me whether I’m using Adobe’s CS6/CC suite, Vegas, or just playing Starcraft :).

Tim
—
Tim Jones
CTO – TOLIS Group, Inc.
https://www.productionbackup.com
BRU … because it’s the RESTORE that matters!