Thursday, December 18, 2003

Disk Test Benchmark Results

Benchmarking a server before I upgrade the RAID controller and drop in larger hard drives.

The current RAID controller is built into the motherboard; Promise FastTrak100 Lite (ATA/100) and I have (2) 160Gb 5400rpm 2Mb cache 11ms drives hooked up. While testing with 4Gb worth of data, and averaging the transfer rate over 300 seconds, I get the following results:

18.500 Mb/sec sequential read
5.586 Mb/sec sequential write
4.212 Mb/sec random read
4.892 Mb/sec random write
(no data for mixture tests)

Sequential read scores are likely affected by the 1Gb of RAM installed in the system (which is why I used a 4Gb data set to try and counteract the effect of memory caching). I'm going to switch back to larger 7200rpm drives with 8Mb cache memory next week and see if I can't get better scores.

Sequential access is comprised of rolling through the data set in sequential order, with a 5% chance of randomly seeking to another area of the data set after each 128Kb chunk is read. Random testing is done with an 80% chance of randomly seeking to another part of the data set after each 128Kb chunk. As a result, sequential scores are not quite top-shelf throughput and random scores are not quite worst-case throughput values. Mixture tests are done by setting the system to have an 80% chance of reads vs writes after each chunk (combined with sequential or random settings). Goal of the mixture tests is to give a rough idea of how the system would perform in real-world conditions. Sequential mixture would be similar to a file server while random mixture would be more typical of DBMS access.

Some comparison values:

A 9 month old SCSI-based server (RAID1 drives) is as follows (odd that random write is larger then sequential write, but it does happen on multiple tests). A test of the (3) discs that were RAID5'd resulted in scores that are around 25-33% lower:

56.418 Mb/sec sequential read
9.590 Mb/sec sequential write
18.815 Mb/sec random read
11.345 Mb/sec random write
18.488 Mb/sec sequential mixture
15.045 Mb/sec random mixture

System with a Promise FastTrak66 (ATA/66) 512Mb of RAM and 7200 rpm IBM DeskStar drives 8Mb cache:

18.990 Mb/sec sequential read
9.547 Mb/sec sequential write
4.722 Mb/sec random read
8.013 Mb/sec random write
9.213 Mb/sec sequential mixture
5.913 Mb/sec random mixture

Labels: Benchmarks

posted by Wuphon's at 12:56 AM