Test Methodlogy - Page 4

- Intel's IPEAK Performance Tools v3.0

The Storage Performance Tool (SPT) consists of five utilities that measure and analyze disk usage in the system:

- AnalyzeDisk: Checks the disk operation independently of the OS or drivers, and reports on the disk surface, sectors, etc.
- Win32 Tracing Kit: Runs a trace of disk activity (reads and/or writes) and stores the data in a binary file for later analysis by AnalyzeTrace, AnalyzeLocality, or RankDisk. The Win32 Tracing Kit does not display the output data.
- AnalyzeTrace: After running Win32 Tracing Kit, use this utility to analyze and display most of the data available from the disk trace.
- AnalyzeLocality: After running Win32 Tracing Kit, use this utility to analyze and display the locality information from the disk trace. Locality is an analysis of the distance (in space and/or time) between disk accesses.
- RankDisk: Can run standard disk benchmarks (‘workloads”) built into the tool or can mimic an existing trace made on one disk onto another disk. In either case, the tool graphically displays the difference in performance between disks.

- "AnalyzeDisk" Utility

This application gives various information about the disk's reading/writing capabilites and features. From that benchmark we mainly get the "Service Read/Write" results:

IPEAK's service time tests uses 25.000 random, single sector read/writes at all the disk's capacity. The resultant distribution of service times is plotted as a probability density vs. service time. This curve represents the probability that a request will be completed in a given amount of time. The service time distribution is not cumulative. The test results can be directly compared to the access time test. User can download the test results and through check the various results himself.

User should be aware for any outliers: "...A well behaved storage subsystems should have any outliers in the service time distribution and the distribution should be narrow. Outliers in the distribution makes the storage subsystem unsuitable for real-time applications, such as multi-media, where variations in service time are detrimental..."

- "RankDisk" Utility

We are using Intel's default RAW traces for both DeskTop/Server workloads:

The height of each bar is the measured mean service time per disk access for a drive stimulated with I/Os from the given workload. Shorter bars represent better performance.

- DeskTop Trace Info

Intel's DeskTop traces include mostly reads but also writes I/O operations.

- Server Trace Info

At the Server strain mode, almost all traces include low reading and mostly write I/O operations.