Storage device performance is characterized by:
- access time which is defined as delay between when a read request is sent to a storage and the moment the requested data starts to flow in.
- throughput is sustained average transfer rate.
We know that RAID0 is capable of increasing throughput. Access time in a rotational hard drive includes the time to move a head above the target track (named seek time) and the time needed a hard disk to bring a requested sector under a head (named rotational latency). Regardless of the count of disks in RAID 0 there is a sector which is in the same moment the furthest from the head (by location) and this sector is not stored in the cache. When this sector is needed the access time will be the same (not better) as for a single hard disk.
If you still intend to improve random access time you should look at this suggestion. In summary – get rid of rotational hard drives and get a Solid State Drive instead.
Arnold's Data Recovery 