Base Ratio | IBM z/OS specification

The new IBM ^zSeries Application Assist Processor (zAAP), planned to be available on the IBM

^zSeries 990 (z990) and zSeries 890 (z890) serv- ers, is an attractively priced specialized processing unit that provides strategic z/OS Java execution environment for customers who desire the powerful integration advan- tages and traditional Qualities of Service a of the zSeries platform.

When conﬁ gured with general purpose Central Processors (CPs) within logical partitions running z/OS, zAAPs can help you to extend the value of your existing zSeries investments and strategically integrate and run e-business Java workloads on the same server as your database, helping to simplify and reduce the infrastructure required for Web applications while helping to lower your overall total cost of ownership.

zAAPs are designed to operate asynchronously with the general purpose CPs to execute Java programming under control of the IBM Java Virtual Machine (JVM). This can help reduce the demands and capacity requirements

on general purpose CPs which may then be available for reallocation to other zSeries workloads. The amount of general purpose CP savings may vary based on the amount of Java application code executed by zAAP(s). And best of all, IBM JVM processing cycles can be executed on the conﬁ gured zAAPs with no anticipated modiﬁ cations to the Java application(s). Execution of the JVM processing cycles on a zAAP is a function of the IBM Software Developer’s Kit (SDK) for z/OS Java 2 Technology Edition, z/OS 1.6 (or z/OS.e 1.6) and the innovative Processor Resource/Systems Manager™ (PR/SM™).

Notably execution of the Java applications on zAAPs, within the same z/OS LPAR as their associated database subsystems, can also help simplify the server infrastruc-

tures and improve operational efﬁ ciencies. For example, use of zAAPs to strategically integrate Java Web applica- tions with backend databases could reduce the number of TCP/IP programming stacks, ﬁ rewalls, and physical inter- connections (and their associated processing) that might otherwise be required when the application servers and their database servers are deployed on separate physical server platforms.

Essentially, zAAPs allow customers to purchase additional processing power exclusively for z/OS Java application execution without affecting the total MSU rating or machine model designation. Conceptually, zAAPs are very similar to a System Assist Processor (SAP); they cannot execute an Initial Program Load and only assist the general purpose CPs for the execution of Java programming. Moreover, IBM does not impose software charges on zAAP capacity. Additional IBM software charges will apply when additional general purpose CP capacity is used.

Customers are encouraged to contact their speciﬁ c ISVs/ USVs directly to determine if their charges will be affected.

With the introduction of the z990, customers can expect to see the following performance improvements:

Number of CPs	Base		Ratio
1	z900	2C1	1.54 - 1.61

8	z900	2C8	1.52 - 1.56

16	z900	2C16	1.51 - 1.55

32	z900	2C16	2.46 - 2.98

Note: Greater than 16 CPs requires a minimum of two operating system images

The Large System Performance Reference (LSPR) should be referenced when considering performance on the z990. Visit: ibm.com/servers/eserver/zseries/lspr/ for more infor- mation on LSPR.