Thinking About Upgrading Your AS400? What is Right For You?
Power 5 vs. Power 6 - The Answer May Surprise You
IBM has finally announced the new Power 6 520 featuring the IBM Power 6 64-bit processor and V6R1.
And with it a hefty price-tag versus the Power 5. So we did an in-depth analysis and to determine if the price performance was worth it.
First, let's look at what the advantages the Power 6 promises. Key themes include IBM's unification of the OS400 (AS400) and UNIX (System p) operating systems onto a single platform. The new family comes in small, medium, large and mainframe. All can run OS400 or AIX (IBM's UNIX) or Linux, or any combination with Logical Partitions (Logical Partitions, or LPARs, are often beyond the needs of most small-to-midsize AS400 users).
In addition, IBM has also introduced the OS400 Power 6 Blade that can fit into a small or medium sized blade chassis. This means you can have a BladeCenter with a combination of Intel processors natively running Windows in the same box as OS400 with any combination of AIX and Linux. A single chassis to accommodate multiple processors and operating systems with a single storage - all part of the trend towards server consolidation. Killer technology - but still beyond most small to mid-size AS400 shops.
With Power 6 BladeCenter Comes Extensive Training Requirements
Why are the BladeCenter beyond most AS400 shops?
The IBM announcement states that Blade users need skills beyond running OS400, Windows and their applications. They need to get training for Blade management software. They need to get training for creating, adjusting and maintaining Logical Partitions (LPARs)…AND training to set up the VIOS (Virtual I/O Server) - the special Power 6 Blade capability that virtualizes the OS400 disk management subsystem to SAS disks or a SAN (this makes the OS400 disk subsystem look like ASCII-based centralized storage). This investment in infrastructure and software skills is typically way beyond the scope of most small and midsize AS400 users.
The Power 6 is WAY More Than 93% of IBM Users Need
Just how large is the small to midsize AS400 user install base? Based on IBM's own count, 93% of all AS400s sold in the last year are 9407-515 or 9507-525. This means that almost all AS400 users need only a single core processor. In most cases, 3800 CPW, which for all practical purposes means that about 1400 CPW (with I/O bottleneck) is more than adequate for this population.
How big is the other 7%?
IBM says they sold 1,000 9406-570's in the last 3 years, which suggests that last year they sold about 5,000 9407-515 and 9407-525, and only 333 9406-570.
The point is that those who benefit most from the performance of Power 6 and its micro-virtualization are 9406-570 users. Most small to midsize AS400 users will never approach the performance capabilities of Power 6.
So the number of buyers who can truly benefit from Power 6 or the Power 6 Blade Center is relatively small… and probably does not include you.
And at cost the additional training, initial set up and ongoing related support, it may simply not be worth it to many.
What Does IBM Have to Offer the Smaller Users - The 93% of Their AS400 Population?
The 9407-M15 is the entry server. It offers a single processor (1 core) with 4300 CPW and 6 disk units (70 GB, 140 GB and 420 GB - but 420 GB only works on V6). The software activation for the processor is $2245 for this P05 server. However, despite its new powerful disk RAID controller with lots of cache, the most performance you can get is about 1400 CPW (simply put, you get about 233 CPW per disk unit). So you don't get any great performance gain with a fast 4300 CPW.
9407-M15 DOES NOT Support IOP-Based Features - NO Twinax or External Tape Drives
Most importantly, the 9407-M15 DOES NOT support any IOP (Input Output Processor) features. So what? OS400 is designed to work in a hierarchy of processors. This means when the central processor wants to send stuff to a terminal, a printer or a disk, the command is "delegated" to a subsystem processor (the IOP card) to do the work; it is not done in the central processor, as with UNIX or Windows. If the 9407-M15 does not use IOP cards, then you cannot support any internal QIC or LTO tape drives (QIC 4GB, 16GB, 25 GB, LTO-2), nor any #2749 legacy SCSI external tape drives (8mm, 3580, 3581, 3582, 3583, 3584, 3576, 3590, 3592), nor Twinax devices like printers or terminals. It also means there is no SNA support or IOP-based Fiber Channel support. Quite simply, the 9407-M15 leaves lots of legacy AS400s stranded if they want an entry-level Power 6.
9406-M25 Supports IOP-Based - But at a PRICE
So how does the 9408-M25 look? On the surface, pretty cool. And the software activation for the processor is $14,995 for this P10 server. However, for devices that need IOP cards (most tape drives and any Twinax printer or terminal), you need at least an #0595 expansion chassis, which lists for about $10,000 when you add up all the doodads required to support it. Hmmm. $22,750 (the $12,750 for M15 + $10,000 for an expansion chassis) to support a $750 Twinax or #2749 tape attach SCSI card. It just doesn't seem right.
I do believe that IBM will rectify some of these IOP issues. Smart IOAs (an adapter card with enough processing capability to support the OS400 hierarchy of processors) are already out and IBM is testing certain tape drives, yet to be announced. Perhaps as early as June 2008 to 4th Quarter 2008, there will have to be more internal tape drives to select from than 4mm. Think about it. How do you perform a complete tape backup of 400 GB with a 4mm tape drive that only supports 32/72 GB? Swap out 6 tapes? I don't think so.
Here is What We Recommend If You Want the Performance at a Value Price
So if the Power 520 Power 6 is not ideal, what to do? Take a close look at the 9407-515. This P05 entry level server can satisfy most small to midsize AS400 users - even those who are told they need a 525 Enterprise Edition. The 515 and 525 are fundamentally the same box with 1- and 2-core processors with 3800/7100 CPW that support the same amounts of memory and up to (8) 70 GB. With (8) 70 GB disk units, you effectively get 1000-1400 CPW for jobs that have lots of disk activity. And a 515 is typically $20,000-$30,000 cheaper than a 525.
Why then would you want a 525? Perhaps most importantly, you can expand the disk capacity of a 525 with 0595. So if you need more than (8) 70 GB disk units (490 GB usable with RAID), than the 525 or the M25 may be the right choice. Or, if you want to support external High Speed Link peripherals like IBM System x or the DS6800 SAN, you can do so with the 525 or M25. Yet you just may be surprised how many AS400 DON'T NEED that stuff.
In many cases, a 515 with 4-8 GB of memory, 490GB of usable memory, and 1000-1400 CPW (that's effective CPW performance, irrespective of the 3800 CPW of the processor) is more than enough to help users with 9406-620s, 720s and 820s - not to mention 170s, 270s and 800s - in the journey to their next AS400.