Storage: SAS or SCSI vs SATA, Which is better?
- How to mount ntfs external USB drive to Cent OS 5?
- 16GB / 32GB (USB) problem – SanDisk Cruzer or Any other USB Drive
- Cloning/Imaging Hard Disk and Partition and Backup Software – Handy Reference
- HDVision N3 Media Player Review: Blu-Ray ROM with Hard Disk, 7.1 Audio, Multifunctional Full HD (1080p)
- Wordpress – Mysql Performance tuner, a free Good Optimizer
I found very useful information about SAS (or SCSI) vs SATA when I wanted to finalize a server configuration. Here is the summary from the pages:
For network storage which is better: SATA 150 or SCSI ultra360? Balance size cost and speed.
There are several ways to look at this. Most of what I say about SCSI also applies to SAS – the serial form of parallel SCSI.
Capacity: SATA drives are up to 1TB, while SCSI drives are still around 300GB.
Price: SATA is around 50 cents per GB, while SCSI can be as high as $2 per GB.
Reliability: SATA bit error rates are 10x that of SCSI. This is critical because errors during a RAID rebuild can cause loss of data. So with SCSI you might be able to get away with using RAID-5, but with SATA you should seriously consider RAID-6. Also, the MTBF of SCSI is reported to be 2-4X that of SATA, but that’s been called into question lately in the Google and CMU whitepapers.
Cabling: SATA is point-to-point, while SCSI is a shared, parallel bus. With SCSI, a cable or drive problem can bring down all of the drives. Note that this is not an issue with SAS – it’s point-to-point like SATA.
Performance: It’s hard to generalize, but SCSI (and SAS) are typically higher performance than SATA. This is true of both seek times, rotational rates, and media transfer rates.
To summarize, SATA GB/$ is a LOT better than SCSI or SAS, but performance and reliability is lower. I definitely recommend that you go with a controller that supports both SAS and SATA so that you keep your options open. At this point, there is really no reason to be looking at parallel SCSI. Also, look at your access pattern and pick the right RAID level. There are plenty of posts in on this site to help you with that. For mission critical applications, SAS is preferred. SATA is preferred for better price/performance rating.
The source and credit goes to storageadvisors.adaptec.com as well as HP storage unit. For Further complete review visit http://storageadvisors.adaptec.com/2007/03/19/sata-vs-scsi/
Don’t lump SCSI and SAS together like this. SCSI (aka Parallel SCSI, Ultra320, etc) and SAS (Serial Attached SCSI) have many different performance metrics. Plus, I can get SAS drives which are 450GB, 1TB, etc. You can’t do that with SCSI.