The Performance Capabilities Reference Manual (PCRM) was THE resource many used when they needed to know something about IBM i performance. That something could be information about performance test results, I/O performance information, performance considerations for IPL, save/restore, partitioning, CPW ratings and many other miscellaneous topics. The last large version of the PCRM was published for IBM i 7.1 in August of 2013. When IBM i 7.2 became available in spring of 2014, that update of the PCRM was substantially smaller.
What happened to the PCRM?
I’ve been asked this questions several times over the past year and figured it was time I wrote about it.
The PCRM had grown bloated over the years. As new releases and new hardware were made available, information was published and carried forward, but not necessarily updated or removed. As such, some of the information had become outdated. Inaccurate or misleading information can be worse than no information.
Because of the challenges with the information contained in the PCRM, IBM changed the approach to documenting performance information. The PCRM is now where information on hardware models and CPW ratings are published, but not much more. Older versions are still available for download if you wish to look back at the prior information.
In order to find all the information related to IBM i performance, you will need to use several sources. These include the following:
- The IBM i Performance FAQ. This is a “must read” for anyone interested in IBM i performance and contains a lot of great information. This should be the first resource you use when looking for IBM i performance information. This document is reviewed and updated two times each year, which generally coincide with IBM announcements.
- The Performance section on the IBM i Knowledge Center
- Articles on the developerWorks site
- Performance information on IBM i Technical Updates site
- And lastly, the i Can blog archive, performance blogs
Many clients liked the “one-stop-shopping” the PCRM provided, but it was cumbersome to update and manage. The IBM i Performance FAQ is the replacement “one-stop shopping” resource and you should be able to use that as the starting point for most IBM i performance questions – although it may very well refer you to the various other sites listed above for more information.
With the new approach you will find the information is more current and accurate and updated on an ongoing basis.
This blog post was updated to fix broken links on April 15, 2020.
This blog post was originally published on IBMSystemsMag.com and is reproduced here by permission of IBM Systems Media.