Piru wrote:
ata and sata use more cpu cycles when you have multiple transfers going on at the same time
Why is that?
here is a quote i found:
For the user who is performance-conscious, who will be doing real multitasking, using many devices at once, doing heavy development work, supporting multiple users at once on the machine, or who otherwise wants the best and is not afraid if it costs a few hundred dollars more, SCSI is the obvious choice. SCSI offers the most flexibility, the most choice of peripherals, and the best performance in a multitasking or multi-user environment.
I dont know the real technical background on why though.. I do however have it verified by personal experience from using both.
Same thing goes for SATA.. It is slower and use more cpu than the SCSI equalent if you have multiple disk with heavy disk access at the same time.
I guess this explains some of it:
ATA drives are cheaper than SCSI or Fibre Channel drives and there's a reason. SCSI and FC drives use a processor for executing the commands and handling the interface and a separate processor controlling the head positioning through servos. ATA drives use a single processor for both which means that if the rotational positioning requires more adjustments due to factors such as rotational vibration or wear, more processor time will be dedicated for that which can affect the performance of the drive. Because of this, you will usually see a lower RPM for the ATA disk drive and also a shorter warranty period. But it is cheaper and can be a very good, economical solution for many environments and applications.
