The Dreamy And Flashy Power 720 P05 Machine
November 14, 2011 Timothy Prickett Morgan
It takes a whole village of smart people to raise a market because no single human being can calculate all of the angles. That’s why there are laws against selective disclosure in the financial services market, and it is also one of the reasons why newsletters such as this one not only persist in the Internet Era, but have much broader impact than magazines used to in days of old. (But online publishing is, alas, a much more difficult and less profitable business than the magazine salad days of the 1980s and early 1990s.) In any event, it takes smart people like you to help each other out through The Four Hundred.
In response to the price/performance comparison for all of the Power7 Gen 1 and Gen 2 machines that I did in the October 31 issue–see Bang For The Buck on Power7 Gen 2 Servers for that–one intrepid and crafty Power Systems shopper told me a little story about trying to come up with a perfect entry Power 720 configuration for an actual workload, which I am dubbing the Dream Power 720 P05 Machine. Take a look:
Run the numbers on this configuration:
The configuration is a P05 machine with 64 GB RAM, approximately 1 TB solid state disk, and supports about 1,600 users on a green screen application running at 30 percent of total CPU across those four cores and at less than 25 percent total storage I/O capacity. Note: The users of this system run RPG apps with DDS files and record-level I/O; I don’t think an SQL application could support that many users on this machine, and that is especially true of a Java app!
This Power 720 machine has 23,800 CPWs of aggregate capacity and over 30,000 IOPS available. It replaced an older system with about 2,400 CPW and 2,000 IOPS.
The extra CPW/IOPS were cheap enough to allow us to buy them, even though they are not being used right now, except to buffer the terminal users from the effects of someone accidentally submitting a resource intensive query. We overbought the P05 system, erring on the side of caution, because at the time the SSD performance was a total unknown to us. We weren’t sure how much CPU was needed to “balance” the I/O performance we were getting. We also needed the capacity of all the SSD modules, even though you can run SSDs at 85 to 90 percent instead of the lower utilization of HDDs.
Note: It was cheaper to do this than to try to buy all the expansion chassis and disk controllers to use hard disks to achieve one-fourth the I/O performance (5,000 IOPS). The reason is that using standard disk controllers would have forced us to buy the GX++ expansion card to connect to an expansion chassis to house the disk controllers, and then the disk expansion chassis themselves. We would have needed at least two (and probably four with mirroring) controllers, plus about 30 hard disks. Start adding up the GX++ card, cables, three expansion chassis, and the drives and it gets expensive fast. Then you can only use 35 to 40 percent of the capacity before you start experiencing extended seek times. That alone is expensive enough (about a wash for all internal SSD), but then attaching any expansion chassis through the GX++ card forces the configuration into the P10 software tier . . . and now the price is crazy expensive. There would have been no way to “buffer” the risk in trying the SSDs if we had to pay P10 prices for the same four cores activated.
As an added benefit to using SSDs, the system IPLs in about three minutes, runs a three-hour batch stream in about 40 minutes, and fits in 4U of rack space instead of 14U.
Not bad for a box that costs $70,000 to $80,000 less than the P10 configuration, uses less energy, and has no moving disks to wear out and need maintenance!
Thanks again for all you do for the loyal AS/400 fans!
–Name withheld on request
First of all, I love this. Now let me take a stab at trying to price it up for all of you.
The base Power 720 chassis costs $338, and the system board with the four-core Power7 chip running at 3 GHz costs $1,200. Processor activations on those cores are $580 apiece at list price, but if you buy a preconfigured Power 720 Express, IBM gives you half the activations for free. So we are only at $2,698 so far for the chassis and processors. The four-core Power 720 machine tops out at 64 GB of memory and you have to use 8 GB memory sticks to get there. The Express configuration comes with a pair of 4 GB features, which cost $1,065 and which you have to remove, and then you need to add four feature 4527 (two 8 GB sticks) for $2,130 each, which costs $8,520. Do the math on this base chassis, and you are at $10,153 for the base system.
Now, let’s add that flashy storage. The feature 2053 SSD adapter cards cost $3,054 each (that’s the low profile version of the card), and the feature 1996 177 GB flash modules that plug into these cards cost $4,400 each. Feature 5630 will run you $1,800, and feature 1909 costs $5,200 apiece (technical withdrawn from marketing on in July 2011, but no doubt still available in the channel). Add it all up and the storage for this machine comes to $74,308.
Hardware comes to $84,461.
Now let’s add the IBM i 7.1 operating system to the four cores. The base IBM i license costs $2,245 with 90 days of Software Maintenance and five free users. If you back out the Software Maintenance bundled into this, you have a license costing $2,057.50 per core with 20 users. That’s $8,230 in total for all four cores. One year of Software Maintenance across all four cores is $3,000. Unlimited users for the machines in the P05 tier is another $18,750. That’s another way of saying at $250 per user, IBM thinks that users above and beyond 95 people should be free. Add the base software up, you’re talking $29,980 for the software, user access to it, and one year of 9×5 business day tech support.
Grand total, $114,441, and in this case, $71.53 per user. That’s less than 20 cents per user per day over the course of a year. When you say it that way, it doesn’t sound so awful, and if you amortize it over four years, it is a nickel a day.