Data Fever: Ultra320 SCSI from Adaptec and LSI Logic

Test Setup

Because we have not used Intel's IOMeter software often up to this point, we would like to briefly explain the test procedure.

IOMeter allows access patterns to be generated for one or several drives, so that a typical system requirement can be re-created. For this article, we used four test processes:

1. Maximum data transfer rate in MB/s
2. AggregateBlock sizeProportion of read accessesProportion of random accesses100%64 kB100%0% (sequential)

No doubt this test is very theoretical and only serves the purpose of determining the maximum transfer rate. We are dispensing with write accesses and random accesses - only sequential reading is in demand.

1. Maximum I/O performance in I/Os per second
2. AggregateBlock sizeProportion of read accessesProportion of random accesses100%512 Byte100%0% (sequential)

In this area, we measured with 1, 4, 8, 16, 64 and 256 I/Os per drive access, since this can vary depending on the controller. Once again, this test only represents a theoretical result, as block sizes of 512 Bytes would hardly be used in practice.

1. File server access pattern (recommended by Intel)
2. AggregateBlock sizeProportion of read accessesProportion of random accesses10%512 Byte80%100%5%1 kB80%100%5%2 kB80%100%60%4 kB80%100%2%8 kB80%100%4%16 kB80%100%4%32 kB80%100%10%64 kB80%100%

In this respect, we measured with 4, 16, 64 and 256 I/Os for each access. The distribution of the required block sizes corresponds to the recommendation by Intel and simulates the environment of a typical file server quite efficiently. We used a total of six hard drives, which ensures high usage of the controller.

1. Database access pattern
2. AggregateBlock sizeProportion of read accessesProportion of random accesses100%8 kB67%100%

The last access pattern is used by other online magazines as well: with a block size of 8 kB, it reflects other database applications.