Green Streak Capacity Planning Guide

by Timothy Prickett Morgan

While some of the price breaks of IBM's "Green Streak" promotion are not as sweet in the fourth quarter as they were in the third, the deep hardware discounts and other cuts are still in effect. If you have a vintage machine and you can squeeze your workloads onto the Model 270 or Model 820 machines on which IBM is offering its Green Streak deal, you've still got time to buy. We've built a Green Streak capacity planning guide to make the shopping a little easier for you.

If you are unfamiliar with the Green Streak promotion, see the article "That iSeries Green Streak Deal Revealed." IBM has since tweaked the deal, so also see the article "IBM Clarifies One Green Streak Deal, Adds Another."

The Green Streak promotion is aimed at getting customers with vintage AS/400 iron to move to iSeries gear. The following characterizes what machines are the primary targets of the Green Streak promotion (and their announcement vintages):

• All Model 170 servers (February 1998, September 1998, and February 1999)
• Model 100 custom server (September 1993)
• All C series deskside CISC-based AS/400s (August 1990)
• All 620 models with processor feature 2179 and smaller; all Model 600 processor features (August 1997)
• Model S30-2258 server and smaller and Model S20-2170 custom server (August 1997)
• All Model S20 and S10 standard server processor features (August 1997)
• Smaller Model 510 with processor feature 2143; all Model 500 and 400 processor features (June 1995)
• All Model 40S, 50S, and 53S server processor features (June 1995)
• Smallest Model 320 with processor feature 2050; all Model 200/300/310 system and 20S/30S server processor features (May 1994)
• All F70, E80, D80, B70 and smaller models in the B, D, E and F series of CISC-based AS/400s (B series machines debuted in June 1988; D series, in April 1991; E series, in February 1992; and F series, in February 1993)

This is a very general classification of the machines that can be replaced with Green Streak machines, but it doesn't really help you figure out what Green Streak machine you can buy if you have a particular vintage AS/400 model. IBM may not be telling you specifically what Green Streak machine is best for you if you have one of these vintage machines, but it sure is telling its sales reps and channel partners. I have obtained some internal IBM documents describing how to target the AS/400 customer base with the Green Streak promotion; these documents can be used as a rudimentary capacity planning guide for customers with vintage AS/400s who are considering upgrading to an iSeries Model 270 or Model 820 under the Green Streak deal. Because of the eccentricities of early server and mixed-mode server models, even if the CPW ratings of your AS/400 might be higher than the ratings of the Model 270 or Model 820 machines offered under the deal, the real-world throughput of that vintage AS/400 might be lower than the CPW ratings imply. What this means is that if you have a CPW rating that is higher than 50 CPW or 70 CPW on your vintage AS/400, you still might be able to move to a Green Streak machine and actually get a lot more work done.

Consider these points that the IBM documents bring up in the following notes in its capacity planning tables:

• Note 1: 6XX and older processors have a single CPW value for both processor and 5250 interactive performance. Both types of processing had to occur within the same total amount of CPW. It was very difficult for 5250 interactive workloads to use more than about 70 to 75 percent of the available CPW (without significant performance impacts on the 5250 interactive response time).
• Note 2: Standard server models can only use about one-third of the stated 5250 interactive CPW before processor performance starts to degrade. Therefore, even though it may appear that the 5250 interactive capacity on a server model is greater than the 5250 interactive capacity of the Model 270/820, this is rarely the case.
• Note 3: Custom mixed-mode servers were special server models that provide both high levels of server performance and significant 5250 interactive capacity. When they meet the criteria, models with these processor features should have a higher propensity to upgrade than standard server models. Usable 5250 interactive CPW is six-sevenths of the stated value before processor performance starts to degrade.

You learn something new every day. I don't know about you, but I didn't know any of that before I read this internal IBM documentation. Oddly enough, the fact that some vintage AS/400 machines might not have exactly delivered the oomph that their CPW ratings might have implied five, six, or seven years ago actually plays into the favor of customers using those machines today. These customers can do a box swap to a Green Streak machine and save a lot of dough, rather than having to buy a regularly priced and more powerful Model 270 or Model 8XX machine. In a twisted way, this is good news.

In any event, the following tables, based on information from IBM, will help you figure out what Green Streak machine might apply to your situation in a very specific manner. IBM is characterizing Green Streak targets as having a high propensity, medium propensity, or low propensity for being appropriate for the deal. In its analysis, IBM indicates if the Model 270 or Model 820 is appropriate as a replacement for a given machine.

To see what machines have a high propensity for replacement under Green Streak, click here.

To see what machines have a medium propensity for replacement under Green Streak, click here.

To see what machines have a low propensity for replacement under Green Streak, click here.

IBM says that customers with Model E90, F80, and 320-2051 systems cannot use the Model 270 Green Streak machine, but should consult with IBM or their business partner, because if they do not use a lot of interactive power in their day-to-day operations, they might be able to get by with the Model 820 Green Streak configuration.

IBM also warns that the Model 820 being acquired under the Green Streak deal does not include a feature card migration tower. Customers can purchase one of these towers to preserve their SPD feature cards--something that IBM is not recommending, since iSeries machines are moving toward PCI feature cards--or buy new PCI features. Nonetheless, IBM says that 10K RPM disks can be moved to the Model 270 and Model 820 with conversion kits that cost $150 apiece, and that the 128 MB memory cards used in the Model 620 and S20 servers can be used in the Model 820. A dozen different features cards used in AS/400 machines can be used in migration towers, including LAN cards, disk controllers, workstation controllers, and various communication cards.

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