SAS or SATA-> Does SAS offer better random IO over SATA?

Question

I am pondering a difficult question. Should I choose SAS or SATA? I ask, because I building an IO intensive application, and would like to know if the benefits of SAS outweigh those of SATA (enough to make it worth the dosh).

I will be placing many relatively small files on these drives, and reading / writing somewhat randomly. I am mindful that in the past, SCSI would usually destroy IDE drives, from a random IO perspective, but IDE was much cheaper. Now I have to choose among their latest incarnations, that of SAS and SATA, but haven't found much information on the internet. with the general exception of various sites saying that they perform somewhat identically (no real details under what conditions).

Answer 1

The controller is by far less important than the drive itself.

• A 7,200 RPM drive performs up to 100 reads/writes per second.
• A 10,000 RPM drive performs up to 150 reads/writes per second.
• A 15,000 RPM drive performs up to 210 reads/writes per second.
• The OCZ Vertex 3 (for example) performs up to 65,000 writes per second (and up to 55,000 reads).

As the speed increases, so does the cost.

Depending on what data you store (and what for), you could also consider a SSD cache. That way, you need only a small SSD for the files that get accessed frequently.