VariCam and SATA Raid at DVinfo.net

Glenn Gipson · July 3rd, 2003, 05:46 AM

I had posted this question in another forum, and it didn't get answered, so I'll try here. The answer to my question maybe obvious though, but I just want to be sure. Can Vari-Cam footage be edited with a SATA (Serial ATA) Raid 0 setup? A 4 drive SATA Raid 0 setup claims to handle up to 266 mbps, so doesn’t this mean that it can be used with DVCPROHD footage (which is 100 mbps, I believe?)

Kai Leibrandt · July 3rd, 2003, 06:12 AM

Though the Serial ATA bus may be able to handle that kind of throughput, you'll be hard pressed to dig up 4 drives that will sustain the individual throughput (you're looking at well over 80Mb/s _sustained_). If you need this kind of throughput you more importantly will need a faster bus (32bit/33MHz PCI is limited to 133Mb/s), such as 64bit/64MHz PCI or PCI-X, which will give you enough bandwidth available. But these motherboards are a lot more expensive, as are hard disk interfaces that will give you this kind of performance (namely Fibre Channel or maybe U320 SCSI with lots of disks).

HTH

Kai.

Glenn Gipson · July 3rd, 2003, 08:23 AM

Thanks

Craig Jones · July 7th, 2003, 08:54 PM

Don't get mb, Mb, and MB mixed up. Hard drives, disk interfaces and PCI buses are specified in MB/s, roughly 8 times faster than Mb/s. It may be hard to find a SATA drive capable of 80 MB/s but 80 Mb/s is a cakewalk.

The transfer rate of an array can be no faster than its member drives, so if your drives can do 40 MB/s, the array can do, at best, 160 MB/s regardless of the controller rating. The PCI bus itself may limit performance or it may not depending on how the controller's integrated into the system. It's hard to say how fast a SATA array will be, but it will be way faster than 266 mb/s and slower than 266 MB/s.

DVCPROHD has a data rate of 100 Mb/s. That's 12.5 MB/s in hard drive terms. Any single SATA drive can do that so a 4-drive RAID0 SATA array will certainly work. The question is how many streams and what are your realtime requirements.

Glenn Gipson · July 7th, 2003, 09:49 PM

Thanks for the clarification Craig. I was only looking to do basic editing with some color correction.

Craig Jones · July 7th, 2003, 10:03 PM

You won't have much trouble getting acceptable performance then. It's 4 times more demanding than DV but hard drives can handle that easily these days.

July 3rd, 2003, 05:46 AM	#1
Glenn Gipson Major Player Join Date: Jan 2003 Location: Plainfield, New Jersey Posts: 927	VariCam and SATA Raid I had posted this question in another forum, and it didn't get answered, so I'll try here. The answer to my question maybe obvious though, but I just want to be sure. Can Vari-Cam footage be edited with a SATA (Serial ATA) Raid 0 setup? A 4 drive SATA Raid 0 setup claims to handle up to 266 mbps, so doesn’t this mean that it can be used with DVCPROHD footage (which is 100 mbps, I believe?)

July 3rd, 2003, 06:12 AM	#2
Kai Leibrandt Regular Crew Join Date: Apr 2002 Location: Munich, Germany Posts: 70	Though the Serial ATA bus may be able to handle that kind of throughput, you'll be hard pressed to dig up 4 drives that will sustain the individual throughput (you're looking at well over 80Mb/s _sustained_). If you need this kind of throughput you more importantly will need a faster bus (32bit/33MHz PCI is limited to 133Mb/s), such as 64bit/64MHz PCI or PCI-X, which will give you enough bandwidth available. But these motherboards are a lot more expensive, as are hard disk interfaces that will give you this kind of performance (namely Fibre Channel or maybe U320 SCSI with lots of disks). HTH Kai.

July 3rd, 2003, 08:23 AM	#3
Glenn Gipson Major Player Join Date: Jan 2003 Location: Plainfield, New Jersey Posts: 927	Thanks

July 7th, 2003, 08:54 PM	#4
Craig Jones Regular Crew Join Date: Jun 2003 Location: Austin, TX Posts: 105	Don't get mb, Mb, and MB mixed up. Hard drives, disk interfaces and PCI buses are specified in MB/s, roughly 8 times faster than Mb/s. It may be hard to find a SATA drive capable of 80 MB/s but 80 Mb/s is a cakewalk. The transfer rate of an array can be no faster than its member drives, so if your drives can do 40 MB/s, the array can do, at best, 160 MB/s regardless of the controller rating. The PCI bus itself may limit performance or it may not depending on how the controller's integrated into the system. It's hard to say how fast a SATA array will be, but it will be way faster than 266 mb/s and slower than 266 MB/s. DVCPROHD has a data rate of 100 Mb/s. That's 12.5 MB/s in hard drive terms. Any single SATA drive can do that so a 4-drive RAID0 SATA array will certainly work. The question is how many streams and what are your realtime requirements.

July 7th, 2003, 09:49 PM	#5
Glenn Gipson Major Player Join Date: Jan 2003 Location: Plainfield, New Jersey Posts: 927	Thanks for the clarification Craig. I was only looking to do basic editing with some color correction.

July 7th, 2003, 10:03 PM	#6
Craig Jones Regular Crew Join Date: Jun 2003 Location: Austin, TX Posts: 105	You won't have much trouble getting acceptable performance then. It's 4 times more demanding than DV but hard drives can handle that easily these days.