Performance at high load

The tables below show the performance which can be achieved with disk accesses of an SU300-80F to the ETERNUS DX440 S2 storage system using many tasks:

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

• Throughput in Mbyte/s

The throughput was measured with 32 tasks operating in parallel 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	60,715	45,979	34,742	11,882	4,574
Sequential write	58,482	45,416	35,149	11,886	4,259
Random25	58,719	44,761	34,780	11,832	4,683

Load type	Throughput in Mbyte/s with 32 tasks and block size
	2 KB	16 KB	32 KB	160 KB	480 KB
Sequential read	112	709	1,108	1,998	2,384
Sequential write	108	697	1,098	1,897	2,012
Random25	110	702	1,106	2,042	2,414

Except when writing with large blocks of over 128 KB, the utilization of the BS2000 CPUs was around 100%. The values ascertained thus correspond to the maximum achievable throughputs with an SU300B-80F (1,200 RPF).

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.