Performance is dependant on many factors.

In General,  RAID 1+0 has Good R/W Performance and RAID 5 has Good Read Performance for sequential reads and fair for random and sequentials writes, also do not forget Write Penalty is High in RAID 5 as compared to RAID 1+0.

For Further information you may refer to below white papers:

EMC FAST Cache - A Detailed Review.

White Paper: EMC Unified Storage Best Practices for Performance and Availability: Common Platform and Block Storage 31.5 — Applied Best Practices

Oh EFD means Enterprise Flash Drive, not FAST.

considering how expensive EFDs are , we try to squeeze as much usable capacity as possible so we go with the RAID config that gives us just that.  Write penalty will be offset by pretty much non existent seek time on EFDs and just its superior IOPS.

I am aware Rob! It's just I threw in one more document, in case he is interested in configuring EFD's for FAST

I wasn't replying to you, was I? No offense ofcourse.

I don't see he mentioned EFD and FAST on the question but I do see that in my response! :S

Anyways, no biggy!

Hi,

I've moved this post to the Host Systems support forum where it can be further discussed.

Thanks.