Disk selection consideration

[Benjamin <benjo11111@xxxxxxxxx>]

Hi,

While we are planning for fast disk, h/w vendor tells that for SAS(15k) 
they suggest raid controller.But as per squid , they do not suggest RAID 
terminology.So suppose if we use disks as normal each single disk rather 
than as single raid ( bunch of disk) with raid controller, is has any 
performance impact?

What is best for disk ? each disk as single disk or need to go with raid 
controller with as a raid ( bunch of disks) ?
Kindly suggest us, what is the better option while planing for h/w 
selection.?

Thanks,
Benjamin