The SPC-1 benchmark result you are referring to is at http://www.storageperformance.org/results/benchmark_results_spc1/#a00092
The purpose of that particular SPC-1 submission was to demonstrate the effectiveness of the DS8000 standard Easy Tier feature at reducing average I/O response time through intelligently and nondisruptively relocating sub-volume extents. Graphs in the detailed Full Disclosure report show this significant improvement occurred as expected. The benchmark was *not* designed to demonstrate maximum DS8700 performance. (By the way, the DS8700 is two generations behind the current DS8870 model which has a published SPC-1 result of about 451K IOPS for an all-HDD configuration.)
I suspect many people who observe SPC benchmark results do not realize that configurations vendors use for an SPC benchmark are not necessarily intended to demonstrate maximum performance a system is capable of. In this case, the purpose was to demonstrate the effectiveness of a feature that automatically improves performance over time, not to demonstrate a maximum IOPS capability.
David Sacks (IBM)