Speed Difference help.. 2x 15.5K SAS vs 4x 10K RAPTOR?

zaim · May 30, 2008, 07:14 AM

i posted this on another forum im active on so sorry for posting here, but i'd like some international responses as well =P

I'm getting this Adaptec RAID 3405 Card which supports both SAS and SATA... and i'm contemplating selling 4 of my 74gb Raptors in RAID0 and getting 2 x 73gb SAS drives in raid0 to replace the raptors i use for my operating system.....

anyone have any personal experience with these 15k.5 sas drives in a raid0 environment? and will it be faster?

Judas · May 30, 2008, 10:25 AM

aside from quicker access times, i think your overall throughput is going to be lower with 2 sas drives then it would be with 4 raptors...

but i'm not certain

procupine14 · May 30, 2008, 04:00 PM

on the fear of feeling like a NOOB what is the main difference between SATA and SAS other than the speed factor? I assume there is some key thing that sets them apart considering that they have the same connectors etc

zaim · May 30, 2008, 10:10 PM

Quote:

Originally Posted by procupine14

on the fear of feeling like a NOOB what is the main difference between SATA and SAS other than the speed factor? I assume there is some key thing that sets them apart considering that they have the same connectors etc

SAS is the new SCSI.. Serial Attached Scsi to be in fact.

these sas drives are 15k rpm, and are quite frikken fast... so im wondering if i will benifit from the quicker latency in raid0 comparing to the raptor raid environment.. it uses the same sata cable, so it's backwards compatible.. but its built strong tough and fast for server environments

procupine14 · Jun 2, 2008, 09:22 AM

well i don't know.....but perhaps those will improve over time as faster SATA bus becomes avaliable?

**dj_stick** · Jun 10, 2008, 04:21 AM

for a sustained data rate, most hard drives can't putout more than 100b/s (P-ATA speed) so there's no way they'll max out the 300mb/s SATA bus anytime soon, though with SSDs on the horizon...

procupine14 · Jun 10, 2008, 01:14 PM

Quote:

Originally Posted by dj_stick

for a sustained data rate, most hard drives can't putout more than 100b/s (P-ATA speed) so there's no way they'll max out the 300mb/s SATA bus anytime soon, though with SSDs on the horizon...

very true

Those SSDs seem to show much promise in the future. Although, isn't there the drawback of SSDs with the multitasking issue or something? I can't quite remember. Im not all on the up and up when it comes to HDDs

H3X4D3C1M4L · Jun 25, 2008, 01:02 AM

A couple of things.

1. Doing RAID 0 or 1 you will be paying entirely for the SAS support with that card. The only time you see a discrete controller increase performance is on RAID 5 or 6 where there are parity calculations and other such things.

2. SCSI drives are fast, sure, but they're not optimised for single user workloads or the kind of work a desktop system usually does. The Raptors will likely beat those SCSI drives for every day use, because the caches have been tuned for desktop use. SCSI drive caches are tuned for constant battering with random IO's, which is something you rarely see on a desktop machine

3. You'd be wiser to spend the money elsewhere if you're looking for outright speed. Regular desktop SATA drives would provide more space at much less cost than the SAS drives. You might also look at the Velociraptor. Two of those in RAID 0, even on an integrated controller on your motherboard, would probably be much better suited to what you're looking for.

That's not to say you shouldn't get the controller and drives because they absolutely won't work. It'll work, it'll be fast. I'm just saying you could have just as much for alot less.