Performance at high load

The tables below show the performance which can be achieved with disk accesses to the ETERNUS DX600 S3 storage system using many tasks:

• I/O rate in inputs/outputs per second (IOs/s)

• Throughput in Mbyte/s

The throughput was measured with 8 tasks operating in parallel on 4 volumes for the standardized load types with different block sizes and a read hit rate of 100%: The The Mbyte figures are rounded to 1 Mbyte/s.

Load type	Number of IOs/s with 32 tasks and block size
	2 KB	16 KB	32 KB	160 KB	480 KB
Sequential read	20.037	14.666	10.893	3.456	1.331
Sequential write	20.187	15.111	11.396	3.803	1.433
Random25	19.799	14.599	10.869	3.459	1.363

Load type	Number of IOs/s with 32 tasks and block size
	2 KB	16 KB	32 KB	160 KB	480 KB
Sequential read	39	229	340	539	624
Sequential write	39	236	356	594	671
Random25	38	228	339	546	639

The utilization of the BS2000 CPUs was around 100% for all measurements. The values ascertained thus correspond to the maximum achievable throughputs with an SU310-20.

As long as the BS2000 CPUs do not develop into a bottleneck, with identical RPF performance the IO rate of x86 servers depends to a great extent on the performance of the disk storage system. Both the cache size and the line speed of the FC interface (8 Gb/s, 16 Gb/s) also play a role.