Although short stroking doesn’t get hard drives anywhere the access times of flash SSDs, we found that their access times still decrease by 40% in the case of the Ultrastar 15K450 SAS HDDs, and by an amazing 50% in the case of the Deskstar 7K1000.B SATA drives. The advantages are similar when the drives are configured in RAID modes. Since no future hard drive will be able to significantly shorten today’s access times, short stroking is an excellent technique for improving performance in a very noticeable way. Even the desktop 7K1000.B shows access times that are quicker than those of 10,000 RPM drives.

Tom's reduced access times on high end SATA drives as much as 40% by formatting only the outer 10-20% of the platters, to minimize seek times of the read heads.

Amusing.

Test Setup, Flash SSDs and Access Time - Review Tom's Hardware : Accelerate Your Hard Drive By Short Stroking