IBM Completes i5 Squadrons with 64-Way Model 595

Throughout the history of the IBM midrange server line, processing capacity headroom was a big issue from time to time. System/38 customers could never get enough capacity, and the first five generations of AS/400 boxes didn’t scale far enough, either. With this week’s announcement of the 64-way eServer i5 Model 595, the headroom issue is moot. This is a lot more box than just about any OS/400 shop will likely ever need to run RPG or COBOL programs against the DB2/400 database.

This monster Model 595 machine, which has a maximum of 64 cores running at 1.65 GHz and can present 128 virtual processors to the operating system, thanks to simultaneous multithreading, has a top-end CPW rating of 165,000, which is 4.4 times the aggregate OLTP processing capacity of the 32-way iSeries Model 890, which was rated at 37,400 CPWs using 1.3 GHz Power4 cores. The funny thing is, IBM could have used the 1.9 GHz Power5 cores and pushed performance even higher, to 190,000 CPWs or so, and with the advent of the Power5+ chips next year and the Power6 chips the year after that, it will be able to extend raw performance even further.

Of course, modern OS/400 servers do not just run RPG and COBOL green-screen applications against DB2/400 databases; they also run data warehouses and Java applications, including Java-based Web application servers, on their boxes. These are the kinds of applications the Power5 chips are designed to support. This is code that likes high clock speed, big caches, and multithreading. So the good news is that customers who want to run a mix of legacy RPG and COBOL and modern CPU-hungry applications based on Java on a single i5–as well as Linux and AIX workloads–now have a box that they can put it all on.

The eServer i5 Model 595 comes in three variants, all of which are based on the same chassis and 1.65 GHz, dual-core Power5 chips. Rather than have a complicated lineup like the eServer p5 line has (the top-end p5 “Squadron” machines will use both the 1.65 GHz and the 1.9 GHz Power5s and offer a 32-way p5 590 and a 64-way p5 595), the iSeries Division just decided to keep it simple, according to Guy Paradise, the iSeries offering manager for this launch. The i5 Model 595 uses the same multichip module (MCM) structure that IBM used in the iSeries Model 870s and 890s and in the pSeries 670s and 690s. The Power5 chip has two cores and a unified L2 cache that the cores share. Along two of the edges of the Power5 chip is an interconnection bus that allows four Power5 chips (that is eight processor cores) to be glued together into a single computer complex. The i5 Model 595s use a cell board structure that puts two of these MCMs on a board (which IBM Rochester calls a book). Four of these books, each with 16 cores and connected into an L3 cache hierarchy that has 36 MB of cache for each MCM, comprise the 64-way machine. The Model 890 was similar, except it used cell boards with only one MCM on each board.

IBM is offering three variants of the i5 Model 595, all of which can be acquired with i5/OS Standard Edition (no green screen) or i5/OS Enterprise Edition (with 5250 processing activated). All of the machines come with a base number of processor cores turned on and then have four cores licensed with i5/OS (yielding 12,000 CPWs of base processing power). The machines running i5/OS Enterprise Edition have those four cores activated with the 5250 Enterprise Enablement features, which means the four cores can be used to support green-screen applications. What customers do with the base cores that are activated but which are not running i5/OS is up to them; IBM probably will suggest Linux infrastructure workloads and maybe AIX consolidation. It costs $21,700 to activate cores beyond the base number in each configuration. It costs $45,000 to activate i5/OS on each machine. It costs $150,000 per core to activate the Enterprise Enablement feature on each core, but for $350,000 you can activate all cores on the i5 Model 595 for 5250-style processing. All of the i5 Model 595 machines are based on a 60U design, which is a full 42U rack, plus an 18U half-rack.

The first i5 Model 595 configuration spans from eight to 16 cores and from 8 GB to 512 GB of main memory; it supports up to 114 TB of disk capacity. (Roughly speaking, this overlaps the capabilities of the iSeries Model 890.) This server is in the P50 OS/400 software pricing tier, which is what a base iSeries Model 890 was in. In the Model 890, if you activated 5250 processing capacity above and beyond the base amount, that bumped it up into the P60 software tier. With the i5 line, adding green-screen capacity doesn’t change the software tier. This 8-16 i5 Model 595 configuration costs $607,300 running i5/OS Standard Edition and costs just under $1.37 million for Enterprise Edition.

The second i5 Model 595 configuration has 16 Power5 cores activated and can span up to 32 cores. However, only four are licensed to run i5/OS in the base configuration. This i5 Model 595 16-32 configuration spans from 16 GB to 1 TB of main memory and can support up to 190 TB of disk capacity. It costs $896,000 running i5/OS Standard Edition on four cores and $1.64 million running Enterprise Edition on those same cores. Like the first configuration, this one is in the P50 software tier.

The largest i5 Model 595 configuration comes with 32 cores activated (that’s 86,000 CPWs) and can span up to the full 64 cores in a single system image. It supports from 32 GB to 2 TB of main memory and up to 190 TB of disk. This biggest i5 Squadron box is in the P60 software tier, however. With four cores running i5/OS, this 32-64 configuration costs $1.45 million running Standard Edition and $2.32 million running Enterprise Edition.

I have added the i5 Model 595s to the traditional salient characteristics table that shows all the speeds, feeds, and pricing of the i5 line. A note on the memory configurations shown in the table: those maximums will be enabled when IBM shifts to 2 Gigabit memory chips, in the second quarter of 2005.

All three variants of the eServer i5 Model 595 will begin shipping on November 19, which is also when the Unix variants of these boxes, the p5 590 and 595, will start shipping. Paradise says that IBM will offer a Capacity BackUp version of the i5 Model 595, which is used for data archiving of live production data, sometime in the first half of 2005. He also says that IBM will offer upgrades to the i5 Model 595 from iSeries Models 830 and 840 in the “Star” PowerPC generation and from the Models 825, 870, and 890 in the Power4 generation.

While Unix customers are allowed to run AIX 5L 5.2, the prior release, on the p5 variants of these Squadron boxes, IBM says that you have to be on i5/OS V5R3 to run OS/400. You can’t run OS/400 V5R2 on these boxes, not even inside a logical partition. This is probably not a result of meanness, but just an admission that i5/OS V5R3 and OS/400 V5R2 are not all that different. The differences between AIX 5.2 and AIX 5.3 are substantial (more like the jump from OS/400 V4R4 to V5R2), and that is why IBM has to support the earlier AIX on the boxes. If it didn’t, it would not be able to sell Unix-based Squadron boxes for about a year, which is how long it will take for the AIX ecosystem to get certified on AIX 5.3. Both AIX 5.2 and AIX 5.3 (which supports micropartitioning and virtual I/O) can run on the i5 variants of the Squadron boxes.