Last Tuesday, IBM took aggressive steps to boost the performance and capabilities of its pSeries servers. While the announcements advance the IT vendor's efforts to increase its share of the UNIX market, they also point toward enhancements that are in the wings for iSeries servers.

In its announcements, IBM made significant improvements to its 8-way pSeries 650 and 655, its 16-way p670, and its 32-way p690. Here is a rundown of the enhancements:

• Faster POWER4+ processors--Currently, IBM's p655, p670, and p690 run on POWER4 processors at the 1.1 Ghz and 1.3 Ghz clock speeds. Starting on May 30, IBM will ship the p655 and p690 with POWER4+ processors running at 1.5 Ghz and 1.7 Ghz, and the p670 with POWER4+ chips running at 1.5 Ghz. These are IBM's fastest chips, and last week's announcement marks their first appearance in production servers. Their use in the pSeries boosts the commercial performance of the p655 by as much as 83%, the p670 by 90%, and the p690 by 65%.
• More memory...more options--IBM is doubling the memory capacities of the p670 (to 256 GB) and the p690 (to 512 GB) to accommodate the increased processing capacity of these servers. In addition, Big Blue is offering a new feature on the p650, p670, and p690 known as Memory Capacity Upgrade on Demand (MCUoD). Under the new feature, customers can purchase a pair of memory cards with only half of their memory activated (on the p670 and p690) or individual cards with no memory active (on the p650). Customers can then activate the standby memory in 4 GB increments; if they are running AIX 5.2L, they can do so without having to reboot the server. IBM has priced the MCUoD memory cards so that customers pay 20% of the cost of the inactivate memory up front. Customers pay the remainder of the cost when they activate the memory.
• New Processor CoD capabilities--Last week's announcement also brought the iSeries' On/Off Capacity on Demand (OOCoD) capabilities to the pSeries for the first time. Owners of p650, p670, and p690 servers can now configure them with inactive processors. These processors can be activated on a temporary or permanent basis to handle increased workloads or replace a failing processor. On the p670 and p690, customers can purchase eight-processor modules with half of the processors inactive. On the p650, customers can order two-processor modules with both processors inactive. Each OOCoD module comes with a free trial period under which the customer can activate two processors for a total of 30 days. These days need not be consecutive, as the customer can turn the processors on and off without having to reboot the server. After the trial period, customers can order additional 30-day activation periods or purchase permanent activations in two-processor increments.
• Better dynamic logical partitioning (dLPAR) and clustering support--Besides gaining POWER4+ processors for the first time, the p670 and p690 are also gaining the enhanced dLPAR capabilities of these chips. The new p670 will support 16 dLPARs while the p690 will support 32 dLPARs; these levels are double those of the previous POWER4 models. In addition, the p655 gained the ability to support four dLPARs. As for clustering enhancements, IBM enhanced its Cluster 1600 software to support p630 dLPARs, p650 dLPARs, and non-partitioned p650 servers as cluster building blocks.
• Enhanced I/O capabilities--IBM also announced support for faster PCI-X adapters on the I/O drawers that most p670 and p690 customers use. To sweeten the deal, the IT vendor added the option to use RIO-2 loop connections on several of its pSeries I/O drawers. Compared to RIO loop connections, RIO-2 doubles the bandwidth between I/O drawers and the central electronic complexes of servers.

The Implications for iSeries Customers

If you're a pSeries customer, chances are good that this announcement is immediately important to you. However, with IBM increasingly building new iSeries and pSeries servers from the same blueprints, last week's product rollout is important for the iSeries as well.

In several respects, the new pSeries models point the way toward what iSeries customers can expect from their servers next year. One potential example of this is MCUoD. While I am not at liberty to say whether this new pSeries feature will make its way to the iSeries, I would suggest that you start asking iSeries executives about it. As you can also infer from the 512 GB memory capacity of the revamped p690 (twice the memory of the current i890), the next generation of iSeries models will likely get a memory boost as well.

Speaking of next-generation models, don't expect the iSeries to ever use POWER4+ chips. The server family is skipping this processor generation and moving to POWER5, a far more powerful chip that should appear on both iSeries and pSeries systems in mid-2004. The first POWER5 chips will likely be built using the same 0.13-micron process found on the POWER4+ chips. Since IBM has pushed POWER4+ to the 1.7 Ghz level, I anticipate that the first POWER5 chips will clock out at a similar speed. Unlike POWER4+, however, POWER5 will incorporate several new technologies that will optimize its performance to a very high degree. IBM's labs are already testing Linux on early versions of POWER5, and the computer giant's executives are confident that they can bring the new processor to market on schedule.

While the pSeries is following rather than leading the iSeries on the processor OOCoD front, it is pioneering a new model for monitoring and managing activated processors. Unlike the iSeries, which requires customers to accept IBM electronic monitoring of OOCoD usage, the pSeries' version of OOCoD is entirely managed by the system software. When a customer inputs a 30-day activation key into the pSeries, the server's Hardware Management Console (HMC) starts counting the days when the processors are active. Shortly before the meter hits 30 days, the HMC starts sending reminder notices to the system administrator. If administrators ignore the messages and run the processors beyond 30 days, the HMC will do nothing to stop them until a system or partition reboot takes place. At that point, the HMC quietly takes back the overdue resources without reporting the infraction to IBM.

Next year, when the iSeries and pSeries share a common system hypervisor and support the same operating systems, the two server teams will have a strong incentive to adopt a common model for monitoring and managing OOCoD resources. While it is anyone's guess whether the less restrictive pSeries model or the more restrictive iSeries model will win out, I have a good idea of which one customers will prefer. If you're considering OOCoD processors for your next iSeries, be sure to let IBM know how you feel about this matter. Your feedback could influence the internal debates that IBM is having about next year's iSeries and pSeries servers.

Lee Kroon is a Senior Industry Analyst for Andrews Consulting Group, a firm that helps mid-sized companies manage business transformation through technology. You can reach him at This email address is being protected from spambots. You need JavaScript enabled to view it..