IBM rolled out its first Power4-based machine at the high end in late 2001 with the 32-way Regatta-H pSeries 690 server, and has been putting variants of the Power4 design into smaller machines since that time. What Big Blue has lacked is an entry machine that supports one or two processor cores that can compete with the 32-bit and 64-bit alternatives in the Windows, Unix, and Linux markets. And now it has it.
All Power4 and Power4+ processors are dual core chips with a shared L2 cache memory on the chip. IBM just rolled out the 1.5GHz and 1.7GHz versions of the Power4+ processor into its pSeries 655 (eight-way), pSeries 670 (16-way), and pSeries 690 servers on May 6. These Power4+ processors are only available in multichip module (MCM) configurations. But the 1.2GHz and 1.45GHz versions of the Power4+ processors, which have 1.5MB of shared L2 cache memory shared by two cores, have been made in single chip versions. This makes them suitable for entry workstations and servers. While the initial Power4 processors were only available in MCMs and therefore were not appropriate in entry servers, customers may think it odd that the various Star 64-bit PowerPC processors – Northstar, Pulsar, I-Star, and S-Star – never made it into entry servers in the RS/6000 and pSeries Unix server lines, there is a reason. IBM’s Power3 and Power3-II processors, which were used in its workstations, had more floating point units and therefore more oomph on technical workloads than the Star processors of nearly double the clock speed. Since IBM had to build motherboards for Unix workstations, it was easier to turn these workstations into servers that trying to turn Star-based servers into workstations.
The pSeries 615, which uses the Power4+ processor running at 1.2GHz, can have one or two cores activated. The odds favor IBM eventually – possibly quite soon – offering a more streamlined version of the pSeries 615 as a Unix or Linux workstation. Jim McGaughan, director of pSeries marketing at IBM, says that the company has no intention of disclosing such future product plans, but this is an obvious way for IBM to pump up the volumes of Power4+ chips that it makes and sells. In the chip biz, the number of chips rolling off the product line is as important to the bottom line as selling the chip in the first place. With high volumes comes perfected manufacturing techniques that have their cost spread across a higher number of units.
The pSeries 615 supports one or two active Power4+ cores, from 1GB to 16GB of main memory, and from 36GB to 584GB of internal disk capacity in four hot-plug drive bays. An additional storage chassis can be attached to the pSeries 615 to give it four more drives, or up to 1.2TB of disk capacity. The machine has six PCI-X slots, two SCSI channels, and two Ethernet NICs (one 100Mbit, one Gigabit) on its motherboard. The pSeries 615 comes in a 4U deskside tower configuration that can also be mounted in standard 19-inch racks if customers want to do that.
McGaughan figures that many of IBM’s customers, particularly in the high-performance AIX and Linux clustering market, are going to want to stack ’em and rack ’em because the pSeries 615 offers the best bang for the buck in the pSeries line. A base pSeries 615 with 1GB of memory and a 36GB disk drive costs $5,745 with an AIX license and one year’s worth of software maintenance. IBM has generally offered a price break to customers who opt for Linux on its so-called Express pre-configurations, offsetting the price of a commercial Linux license, but not so on this entry configuration. The Linux-ready Express machine costs the same $5,745. But as customers buy bigger pSeries 615s, the Linux discount kicks in. A two-way pSeries 615 with two 36GB disk drives and 8GB of main memory costs $15,600 with an AIX license and software maintenance, while a Linux-ready version of the same iron costs $14,600.
McGaughan says that the uniprocessor versions of the pSeries 615 are available immediately, with two-way machine available on June 20 and Cluster 1600 implementations available about a week later. The pSeries 615 with a single 1.2GHz Power4+ chip core activated offers about 110% more performance than a uniprocessor pSeries 610 using the 450MHz Power3-II processor; with both cores activated, the Power4+-based pSeries 615 offers about 78% more performance than a two-way pSeries 610 using the 450MHz Power3-IIs. (The difference in performance on the uniprocessor and two-way comparisons can be attributed to differences in caching structures. A single-core Power4+ has all that 1.5MB of L2 cache to itself, while a dual-core chip has to split that cache, and therefore the effective performance per core goes down.)
The pSeries 615 will support AIX 5L 5.1 or 5.2 SuSE Linux Enterprise Server 8. IBM is working with Turbolinux to roll out its version of Linux on the pSeries 615 in the Asia/Pacific region, starting with Japan. IBM won’t pre-configure Linux on the machines, but it will allow customers and channel partners to make a Linux order when they buy a pSeries machine and then pass the Linux OS order on to the commercial Linux distributor.
Source: Computerwire
