In terms of transfer rates, and in GENERAL... raid is faster, but transfer rates don't mean much. Raid could be scsi/sata/ide so it's a bit of on odd question. Generally scsi>sata>ide
RAID isn't an interface, it's a protocol. However disks in RAID0 or RAID5 (or some variant) will be fastest. SATA has a higher bandwidth but unless you get a 16mb cache or NCQ drive there's really no difference in speed between it and PATA drives since drives won't saturate ATA/66 unless it's a 15kRPM SCSI. SCSI has the moth bandwidth but is friggen expensive to set up, SATA's the best IMO since it has small cables, reasonable drive prices (a hair more than PATA but far less than SCSI), is integrated on all new mobos and is futureproof for quite a while.
Depending on speed, no SCSI is faster. Setting up a SCSI system can be a long complicated process and the drives are know to be noisy. I recommend for cost/speed combo, X amount of SATA drives on Raid 0 with 16MB cache and Native Command Queuing. With 4 drives on this setup you will achieve high speed results should be hitting the max 150mb/s mark, more on later boards and/or with more drives. Also forgot to mention SCSI = ridiculously expensive. And with Raid 0 backup!
Depends of the SCSI drive as to whether it's faster than SATA. Some are very slow (7.2k ones). 10k -15k are normaly quicker again it depends on the drive. For a scsi setup you'd need a SCSI card, cable. drive and possibly terminator.
Are you asking about SATA II? Which is marketed at 3Gb/s and incoprates NCQ? Edit: Ok I did do a little more looking. SATA-300 is out on the nForce 4 boards, at least the SLi ones. As for drives, Seagate has NCQ dives out, as does WD in the form of the 74gig raptors with TCQ. But they aren't SATA-300. From what I have read, they aren't even maxing out SATA-150 yet. It seems that SATA II is more a future proof technology, not unlike PCIe. Remember that HDs are the technology that is most bound to a mechanical movement. We are not even using SATA-150 to it's full pontential yet, so SATA-300 drives are most likely a ways off. But having a chipset that supports SATA-300 will definatly make sure that there isn't a bottleneck.
SCSI RAIDs are nicer than SATA RAIDs imo, with software RAIDs been the easyest (and suprise me in how little CPU they take up in windows, HK reliably tells me he's had good performance with BSD ones). SCSI is expensive, but the quality is soo much more, i've had one SCSI drive die on my/comps i service EVER. And that was a maxtor so no suprise i guess. SATA RAIDS, don't go NEAR an adapatec controller, they are bug ridden to hell. SATA RAIDS are definatly cheaper, but if you're doing MODE 0 and want some increased peice of mind, the SCSI price is well worth it, i only recomend for co-lo'd servers SCSI now, SATA's been too much pain (had some raptors die was a PITA getting them RMA'd WD dragged on each time, saying they were fine, when smart was saying they were at 95% fitness and the bad cluster count had surged!) In short, if you've got lotsa dosh go SCSI, or you can buy RAID spares that are been ritten off (lotsa 18gig 15k rpm drives going for about £30-40 each, all have about 5 years warenty left (only 2 years old) a mate of mines just set up two nice RAID 10's on these for OS+PROGGIES and GAMES partitions, means he has peice of mind and awsome speed). SATA, 150 is about all thats out and afordable, if your looking at getting hold of 300 drives, just goto SCSI now. So, probably SATA's best, no need for 10k rpm drives, if you can afford it RAID 10, if not 0 and as said before, backup LOTS.
IMO go for SATA. I have a pair of 10K U160 SCSI drives and tbh they dont give any speed increase over the 250GB SATA for boot/loading programs, plus they are loud. They perform better in synthetic benchmarks (for random access), but real world difference isnt noticeable to me. So Im going to sell my drives and move on. You could get newer SCSI (U320+), but itll cost.
