Counting The Cost Of Power8 Systems

July 14, 2014 Timothy Prickett Morgan

Now that IBM has put the four-core entry Power8 machine in the field to appease the processing and software group needs of a large portion of the IBM i installed base, it seems like now is a good time to finally get the price/performance analysis comparing Power7, Power7+, and Power8 machines out the door. There are many ways to dice and slice this, and I like to go through this methodically, as you all well know.

I have already compared the base system configurations in terms of their feeds, speeds, price, and raw value for dollar based on IBM’s Commercial Performance Workload (CPW) online transaction processing benchmark test. These are but crude relative gauges of price/performance, I realize. That is why I also create comparisons that look at the price of raw processing capacity and the IBM i software license and support. That is what I have cooked up for this issue of The Four Hundred, to show you the cost of the inherent processing capacity separate from the system chassis and the memory, storage, and other peripherals that get added into the system. The next thing will be to look at how configured systems stack up using different generations of Power chips running IBM i and then to compare configured Power8 boxes to similarly configured machines equipped with Windows, Linux, and Unix as well as hypervisors and databases like IBM i offers.

All of the feeds and speeds and prices of the processor feature cards used in the Power7, Power7′ (remember those?0, Power7+, and Power8 lineup are included in this monster table that I created four years ago with the Power7 chips and have updated as new machines came out. This is a big spreadsheet and it takes some time to load so be patient. This does not include the Flex System machines, which I will add at some point. Most IBM i customers are probably still buying rack and tower versions of the Power Systems and not Flex System iron, if the penetration of IBM i on the BladeCenter blade servers from years gone by is any guide of how these customers feel about paying even more of a premium for iron than they already do. The machines in light green are the Power7+ boxes, and those in light blue show the new entry Power8 systems, just to make it easier on the eyes. (I think that’s what the colors are, anyway. You should not trust my eyes when it comes to nuances of blue and green.)

As I have done in the past, these configurations show the cost of adding a reasonable number of users running the full IBM i suite on all of the cores in each processing feature. There are 40 users on the entry machines (Power 720, Power 720+, and S814 in the IBM i P05 software tier), and there are 300 users on the P10-class machines. The machines in the P20 and higher software tiers have an unlimited number of users per core activated, so user pricing is built in by default. I have stripped out the three months of Software Maintenance bundled into the initial license for the machines and then added on a full year of SWMA. (This chart I built two years ago shows IBM i pricing compared to AIX pricing, and as far as I know, prices have not changed.)

Here is a refresher of how the costs of processing, IBM i software, and support added up on the entry Power7+ machines that came out in early 2013:

As you well know, once you get off the four-core variants and out of the P0% software tier, the cost of computing per CPW unit of performance went up radically with the six-core processors and went up even higher with eight-core machines. And once you move into the P10 and higher tiers, it can get very pricey indeed. The same pattern holds true with the Power8-based Power S814 and Power S824 machines, as you can see below:

The pattern is the same, but the good news is that the absolute cost of computing capacity is way down because a Power8 core is delivering somewhere around 10,000 CPWs of performance at the clock speeds IBM has set with the initial Power8 boxes, which is about a 50 percent increase in performance with the Power S814. On the smaller configurations of the Power S824, the core is producing around 12,000 CPWs of oomph, compared to around 7,500 CPWs for the Power 730+ and around 7,100 CPWs for the Power 720+.

IBM has not provided official CPW ratings for the four-core, 3.02 GHz processor option in the entry Power S814 machine, but I am pretty confident that it will be around 39,800 CPWs. And if you do the math, that is 40 percent more CPW performance at the system level but the cost per CPW falls from 75 cents with the Power 720+ to 53 cents with the Power S814. That is a 29.3 percent improvement in price/performance on a fully burdened processor card. As you can see, moving up to the six-core and eight-core variants, the cost per CPW for processor cards including the OS and one year of support goes up by a factor of five. That is a pretty steep curve, but it is one that IBM i shops are well acquainted with. The good news is that this cost is a tad bit lower than the cost per CPW on the Power 720+ machine, about 20 percent lower, give or take. But it is hard to imagine paying $150,094 for a six-core processor card or $206,260 for an eight-core card, but that is the price.

The hardware is not something to worry about, so if you want to push for big discounts, get seriously aggressive about getting IBM to chop IBM i licensing costs and Software Maintenance costs. And make sure you lock in those discounts not just for the one or two cores you activate today, but the ones you will want to install with IBM i in the future. Because, as the following charts and the monster table show, the IBM i dollars sure do add up. That is because all database makers are changing a hefty premium for relational databases.

Here is the hardware, software, and support cost breakdown on the entry Power7+ machines, with the software licensing for IBM i 6.1, 7.1, or 7.2 representing somewhere between 60 and 70 percent of the cost of the processor capacity on Power 710+ and Power 720 machines:

On the Power S814 machine, software actually represents a slightly smaller part of the bill, and that has more to do with keeping the number of users constant between Power7, Power7+, and Power8 machines than anything else. (After a certain point, you can get unlimited users on these smaller machines).

On the larger Power S824 machine, which has two sockets, the software accounts for more than 80 percent of the costs. (Something weird happened in that Excel chart, Excel crashed, and lost all of my work in making the Power8 charts, so I am not showing you the red bars going all the way out past 80 percent in the chart above. Sorry.) The point is, the processor card and core activations on Power8 machines is a fraction of the cost of the total cost of actually using and supporting that capacity. Support is generally more expensive, and the software is as much as eight times as expensive as the hardware.

This may or may not be any different from what other systems have to offer in terms of pricing, and we will explore that in future editions of The Four Hundred. Stay tuned.