The Power7 Chip Gets Some Stiff X64 Competition
April 5, 2010 Timothy Prickett Morgan
Three quarters of the X64 assault on the midrange server market have been deployed into the field, with last week’s launching of Intel‘s eight-core “Nehalem-EX” Xeon 7500s and Advanced Micro Devices‘s 12-core “Magny-Cours” Opteron 6100s. Three weeks ago, Intel put the six-core “Westmere-EP” Xeon 5600s out, and that only leaves the six-core “Lisbon” Opteron 4100s left to enter the price war battlefield sometime in the second quarter of this year.
As the X64 chip makers and their OEM server partners start firing away at each other to compete for server deals in this still rickety economy, it is the entry and midrange Power Systems business (as well as the equivalent Itanium iron from Hewlett-Packard and Sparc machinery from Oracle) that may get shot up in the crossfire.
In my other life as the Systems Editor over at The Register, I have gone through the announcements for the Xeon 5600s, for the Xeon 7500s, and for the Opteron in great detail. I have also analyzed the sales pitch for the Xeon 5600 and the marketing spiel for the Opteron 6100. Intel didn’t offer much of one for the Xeon 7500s, but as I told you in The Four Hundred a month ago, vendors like IBM are using the SMP and NUMA capability of the Xeon 7500s in clever ways to create two-socket and four-socket machines with expandable SMP, snapping together machines much like IBM has done with the Power 570s for years, but also allowing for memory subsystems to be snapped into the Boxboro chipset from Intel to allow very fat memory configurations.
Take the IBM BladeCenter HX5, which was announced last week from IBM using the Xeon 7500s. This two-socket blade has room to support 128 GB of main memory using 8 GB DDR3 memory sticks in its 16 memory slots. But using a Max5 memory extender card, another 24 memory slots can be added to this two-way machine, bringing total memory up to 320 GB. That’s a lot of memory, to be sure, but when it comes to virtualized servers, memory is often the limiting factor, not CPU power. Which is why server makers are not talking about scaling Xeon 7500 systems to 16, 32, or 64 sockets, but rather scaling memory for machines with two, four, or eight sockets. (This was probably not what Intel wanted to hear, but it sure beats, “Screw this, we’re building blades with Opterons.”) And with the FlexNode capability of the HX5 blade, two HX5 blades can be snapped together gluelessly, allowing for customers to make a two-way machine into a four-way machine if they need to add CPU capacity. And, here’s the kicker, they can add another Max5 memory expander to this, yielding a four-socket, quadruple-wide blade server that has a whopping 640 GB of memory. And when 16 GB DIMMs are supported, how’s 1 TB grab you?
Now, compare this to the existing BladeCenter JS23, a two-socket blade with a measly 64 GB max of DDR2 memory, or the four-socket JS43, which has this same FlexNode SMP capability, but only has its on-blade memory slots for a maximum of 128 GB. The Power6 and Power6+ versions of the JS blades did not have memory expandability as IBM is offering with the Max5 feature on the Xeon 7500-based boxes. And as I have been saying for years now, this kind of modularity, which allows CPU, memory, and I/O to scale independently, would be necessary. The System x people seem to have understood this, and I am hoping that the Power Systems people get on the ball. Particularly with whatever Power7 blades are coming–let’s call them the JS27 and JS47 just for fun–as well as for the Power 720 entry box.
The System x3850 X5 is a four-socket box that looks very much like a Power 570 and Power 770, in that it is a box that gangs up two, three, or four chassis into a single system image if customers need to grow beyond a single four-socket box. (When a System x3850 X5 gets a kit to do this NUMA clustering, it is called a System x3950 X5, much as Power 570 is really a clustered configuration of Power 550s or the new Power 770 is a clustered configuration of Power 750s.) Again, the big difference is that the Xeon 7500 machines pack a lot more memory than the Power7 machines and they also have the Max5 memory expansion to push it even further.
A four-socket Power 750 (which uses Power7 chips with either six or eight cores activated) tops out at 512 GB of main memory using 8 GB DDR3 memory cards, and the Power 770 tops out at 512 GB even across four nodes and will not get support for 2 TB of memory until 16 GB memory cards are available in November. Those will be very expensive cards, I will bet. Contrast this with the System x3850 X5. The basic four-socket box, which can be deployed with Xeon 7500 chips with four, six, or eight cores per socket, can support 1 TB of memory using 8 GB memory cards, which will be a lot cheaper than 16 GB cards. And, if you really need more memory today, IBM is also supporting those 16 GB memory cards right now. No waiting til November. Moreover, in June, the x3950 X5 expansion feature will be available, allowing for the system to be doubled up to eight sockets and 2 TB using 8 GB memory cards. The x3950 X5 will eventually be scaled up to four chassis, and 8 TB of shared memory using these mostly affordable 8 GB memory modules.
Now, answer me this: How come IBM is offering four times as much memory on the System x box as on the Power Systems machine? Which is the flagship midrange product again?
The machine I like best, and which embodies some of the design principles I talked about in the System iWant, 2010 Edition, stories I put together earlier this year, is the System x3960. This is a two-socket Xeon 7500 server that has 32 memory slots and room for 16–yes, I said 16–2.5-inch SAS disk drives across the front of its 2U chassis. Using Max5 capability, this machine can have an additional 32 memory slots added to it in a 1U memory module, for a total of 64 memory slots and up to 1 TB of memory using 8 GB DIMMs. Or, if you are cheap, you could get to 512 GB using 4 GB DIMMs, and that’s cool, too. The System x3960 X5 is not shipping yet, and more details of the machine are not yet available.
There is no Power Systems machine that looks like the System x3960 X5. But I find myself hoping that the Power 520 has similar integrated storage and memory expansion capabilities.
If you want to see all the feeds and speeds of the IBM Xeon 7500 server lineup so far, check this out.
In the coming weeks, as systems and their prices are delivered, I will start ginning up competitive analysis for these entry and midrange boxes. I can’t wait to see how this stuff is all priced.