Does RAID 0 improve your enkoding speed?

[Markstar]

Hi,
a long time ago I briefly set up a RAID 0 to see if that would improve my encoding speed (2 PATA drives with a PCI controller). As VDub actually took longer to finish encoding, I quickly went back to using the HDs independently.

Now, in the time of dual core processors and some additional 10k rmp SCSI hard drives :p , I'm wondering if anything has changed or if I made a mistake back then.

Do you guys have/use a RAID setup? And does it significantly speed up your encoding-time? How about other tasks except gaming? Do you notice the difference?

Any opinions on that matter are very welcome!

Greets
Markstar

[shakey]

Encoding is pretty much cpu/ram speed limited, unless you're doing an encode with extreeemely low compression. So you'll probably not see any speedup by encoding from/to it. Where RAID 0 might help is if youre copying large files (eg movies) from one place to another. For example, copying a large file from 1 raid 0 array to another will be almost twice as fast as from single hard disks.

So for encoding, unless you're planning on doing lots of moving of files and are willing to set up two arrays, it's probably not much of a help.

[Blue_MiSfit]

RAID 0 is really best applied to situations when hard drive bandwidth is the primary bottleneck. This is distinct from hard drive seek time.

The main reason that SCSI is better than IDE / SATA for almost every task is that the higher spindle speeds permit lower seek times. RAID doesn't really improve seek times, only raw transfer speeds.

So the only thing that really sees a significant benefit with RAID is things like working with very very very large files, like uncompressed HD footage, and transferring files around between multiple RAIDs. It's also logistically a lot trickier to handle, especially if you multiboot.

~MiSfit

[Turtleggjp]

Back in the day when I used to do analog capture (uncompressed) I used two WD Raptor 74GB drives in a RAID 0 and they worked beautifully. That however is an example of a task that is very HD I/O intensive, which is why it benefits greatly from the RAID 0. From that point, when running it through the compression (and often IVTC) phase, my CPU would not hit 100% because the HDDs could not supply the uncompressed data fast enough to fully utilize my CPU, since it was no longer reading in large sequences. However, now that I'm dealing mostly with HD video captured in MPEG2 TS format, HDD speed has become irrelevant (except when moving the captured files around). Like Shakey said, it's all CPU and memory now. If anything, you slowdown using RAID 0 may have been because the CPU had to do more work managing the RAID, so it had fewer cycles to spend on the actual encoding.

Matt

[Blue_MiSfit]

Right. Unless you've got a badass hardware RAID controller, like this bad boy: http://www.sonnettech.com/product/tempo_sata_e4p.html

20x750GB SATA = 15 TB Max :D

~MiSfit

[Turtleggjp]

20x750GB SATA = 15 TB Max :D

Wow, by my calculations, that could be about 44 hours of uncompressed 1080i HDTV! So at $380 per drive and $300 for that card, that's gonna come close to $8000. But it probably won't make your DVD encodes go any faster :(

Matt

[Markstar]

Well, I have decided to switch to 2*RAID-0 for now since I do a lot of direct stream copying and moving files around (just copied the the Ubuntu 6.10 image in about 6 seconds :eek: ). Plus, since my system and video files are on SCSI, I hope that additional CPU load will be minimal. :o

And, even with the limited experience so far, Windows is considerably faster until now. :)

Anyway, thanks a lot for the input!