SAS vs eSata
 

I'm building a raid with Sata drives in an external enclosure for editing. Are there any advantages to using the new SAS HBA vs an eSata HBA?

I've been using eSATA on my desktop and notebook for archiving HDV material with no trouble. The 3GBps interface allows the full native drive speed. As I see it, 3GBps SATA drives are effectviely the same speed as SCSI drives without the premium you pay for the SCSI interface. [SAS HBA is a slender serial interface cable back to SCSI drives with their bulky cables]. The raw drives (Seagate et all) are the same and the better ones have scatter-gather, just like SCSI has had and IDE lacked.

The only wrinkle I have encountered is my notebook SIIG ExpressCard adaptor (under Vista) would not read the drive originally formatted on the desktop under XP. I don't know if that is Vista's problem or the notebook adaptor. My solution is to format new drives as NTFS on the Vista notebook first. Same username was used on both machines, if that might make a difference on permissions.

That's good to know about the laptop. I would like to be able to use the drives with both a laptop and desktop. Is your setup using a port multiplier or the individual cables?

Which external case will you be using and with how many drives? A port multiplier cards tends to only work with highend PCI-E x4 slots or PCI-X 133 slots. As far as I know there is no port multiplied option for a laptop. If you wanted your external raid box to work with both a decktop and a laptop it would have to be eSATA.

For the life of me I could never figure out why there were not more devices that could do a hardware raid that was just sent over a single SATA cable. I mean 300MB/S is some pretty high bandwidth that even a 4 drive raid should easilly pump through. I never really like port multiplied radi boxes because they pretty much just pumped the drives to the system and then you had to setup a software raid. I would much rather have a true hardware raid that was done 100% inside the external box and then just use a single cable to pump that raided data to the system. This is the way some of the smaller devices such as G-raid works. Except in most of those cases they use firewire 800 to feed the raided data to the system which works ok for a 2 drive raid. eSATA is a much fatter pipe to pump data from a 4 or more drive raid.

I haven't tried it out yet but I have been looking into building external hardware box raids with 4 drives each that pump out through eSATA. I would build 4 of them and then raid those inside the system for a 16 drive raid. I'm sure I would reach a cap for the bandwidth but it would allow me to sustain 300MB/S for a very long time.

Since my objective was to have a transportable archive drive with good enough performance should I ever need to edit on it with the laptop, I now have a single drive, single cable solution. Since all the SATA ports on my mother board (Abit AW8-max) were occupied with a 4 drive RAID5 root and 2 drive RAID0 video array, I added a PCIe card to get the eSATA connector for the desktop. The notebook SIIG card is a 34mm express card with two outlets, non-RAID, so I could add a second "work drive" to accompany the "archive drive". The express card is inexpensive, so switching to a RAID capable one in the future is always an option.

Don - Thanks for your setup info. I think I will need a little more power than that as this will be my editing drives.

Thomas - I'm looking at some no frills enclosurers at PC Pitstop or an Ice Box at another site whose name I can't remember. I plan to start with 3 drives. I have a PCIe 8x slot available and will probably be using either the 2314 Rocket Raid esata card or the 2322 Rocket Raid SAS card. I believe either would be a hardware raid setup? The esata solution would be cheaper, but if I want to be able to use the raid with a laptop it looks like the SAS would be better. I've seen SAS cards for laptop express slots. The other option would be to get a case with the raid built in so that the card in the computer wouldn't matter as much, but this is more expensive. I'm trying to stay at $700 - $800 for the raid setup not including any laptop connections.