SATA for uncompressed?

[Charles Simonson]

Please do not go by QuickBench or any other disk bench utility to determine the actual speed throughput of the drive. Ask Walter Biscardi about this, as he has run many tests regarding benchmarks to real-world use. Just today in fact, I ran a benchmarking test with AJA’s utility on a FW800 LaCie Bigger Disk 1TB drive, a 73GB 10K Ultra320 SCSI drive, a 1TB 14x73GB 15K Ultra320 RAID, and a 1.6TB 4x400GB 7200 SATA RAID. With the utility, it was reported that the FW800 and the single 73GB SCSI drives could not handle playback or capture of Uncompressed HD 8bit video. That was to be expected. The utility also reported that the two RAID configurations could handle HD Uncompressed playback and capture “with plenty of speed to spare”. Well, when I played back a 720p60 Uncompressed 8bit movie, the SCSI RAID handled it with ease and the SATA RAID choked, maxing out at about 7fps. Numbers were similar with playback of 1080p24 content. Both RAIDs were about equally full with content (~60%).

So, it really is best to not go by what some benchmarking utility tells you what you should be getting in real performance. The only way to test this out is by actually using the type of movies and files you expect to be working with on those drives. And I can tell you through my experience that the throughput of just 2 drives striped in the real world is not that great of an advantage over single drives. Yes, you should notice some speed increases, but it will not be dramatic. Drama starts with three drives striped, and four is getting an Emmy nomination.

[Gary Adcock]

[Charles Simonson] “The only way to test this out is by actually using the type of movies and files you expect to be working with on those drives. And I can tell you through my experience that the throughput of just 2 drives striped in the real world is not that great of an advantage over single drives. Yes, you should notice some speed increases, but it will not be dramatic”

I agree and disagree. YES you should be testing your hardware with content like you will be working with, and the best for that is a job you have already worked on.

But I disagree on the drive speed, Many factors are involved with drive speed from CPU to the types of drives you are working with (FW drives are notoriously slower due to the FW to ATA bridging) Native drives like SATA and SCSI are going to be faster hands down.

Based on a single drive on a single bus (SATA)

2 single drives on a single buss is 10% slower
4 single drives on a single buss is 25% slower

2 drives in a Raid config on a single buss will be 50% – 75% faster than a single drive
2 drives each on on separate buss in a RAID config +180% faster than a single drive

these numbers are for extrapolation and very on every machine I have worked on.
I currently have 2 identical SATA arrays in for testing and I am seeing differences between where the SATA card is placed in the PCI bus on G5’s ( hint: Slot 4 is always faster — DOH!!)

gary adcock
Studio37
HD and Film Consultation

[Stevesherrick]

I understand that as the amount of drives in the Raid increases, the throughput will be greater and more capable of handling the uncompressed streams. But I see no harm in striping the 2 drives together to gain some performance over the single drives, even if it was only marginal, which so far it seems to be more than marginal based on what I can now play. The risk involved is the Raid 0 configuration which could result in me losing all my data if one of the drives go bad. But I backup my media to firewire drives, so I can negate that risk. Firewire drives, even the firewire 800 at times is just too unstable for me. I had added multiple firewire cards too, but it just didn’t seem to cut it, even in DV sometimes. Got the occasional dropped frames. I just wanted a stable storage solution. I have a UL3d SCSI card with a Medea Video Raid RT but that only gets a sustained data rate of about 65mb/s and the SATA raid is getting more than that. SCSI is just too expensive for me with the amount of space you get. Eventually, I’d like to get the best storage solution out there, but right now this is the best I can do.

Steve

[Ryanservant]

Now I am super confused…..I bought 8 seagate barracuda’s ( 400 gb each ) and I bought 4 firmtek dual enclosures, I also bought a 8 port PCi sata card from Sonnet. I have been using it for uncompressed 8 bit HD and so far it has been ok. But now all of a sudden FCP is crashing on me if I run the scrubber around the timeline and play and stop etc. It seems like as soon I tyr and push the drives a bit FCP crashes. Is this because of my drives? I made one big raid with the 8 drives. I did raid 0. Is this totally wrong? Blackmagic’s Disk speed test is telling me 8 bit 4:2:2: HDTV reads at 92 and writes at 42. But it also tells me that disk read data rate in MB/s is 365.6 and disk write in MB/s is 166. Is this ok?

thanks

My xserve reads a bit slower but writes a bit faster…so I didnt think that would be an issue..maybe I just need more ram and I am posting in the wrong thread

G5
xserve 2.5 TB
FCP HD
2 gigs ram
Used to be Kona Hd…Now its Decklink HD pro

Ryan Servant
AirSeaLand Productions
http://www.airsealand.com
718-626-2646