IBM Readies Big Iron With “Cumulus” Power9 Chips
July 30, 2018 Timothy Prickett Morgan
The Power Systems lineup has been updated top to bottom on single-socket and dual-socket machinery based on the “Nimbus” variants of the Power9 chip, which sport up to 24 cores per die and have up to four threads per core. These Nimbus chips are used in all kinds of machines, including those that can run IBM i, either alongside AIX or Linux using the PowerVM hypervisor or in what is made to look like a bare metal IBM i setup but which is really a PowerVM machine with one partition. (Shhhhh.) The Nimbus processors are also deployed in supercomputing nodes (the “Newell” Power AC922), the “ZZ” mainstream machines, and the “Boston” Linux-only systems.
Now, it is getting close for “Zeppelin” and “Fleetwood/Mack” to take the Power9 stage with the “Cumulus” Power9 variant, which sports up to 12 cores per chip and eight threads per core and which also makes use of the “Centaur” memory buffer chip and L4 cache memory to provide roughly twice the memory capacity and bandwidth per socket.
This is the big iron that many IBM i and AIX customers have been waiting for, and maybe even a few customers doing in-memory and other kinds of analytics processors on Linux who are sick and tired of managing clusters to get big jobs done. For NUMA ware applications, a NUMA system is just so much easier to program, even if it does cost a bit more. (Not if you count the cost of that programming on cluster systems, of course.)
We had heard way back in February that the plan for these two machines, which we presume will be sold as the Power E950 and the Power E970/E980, respectively, was to get them out the door some time in the third quarter. We expected that IBM would launch the four-way Zeppelin Power E950 first, to be followed up sometime later by the Fleetwood Power E980, which scales from one to four enclosures and which has a NUMA management controller that is codenamed Mack. (As in the truck.) We told you all that we could find out about the Fleetwood/Mack system way back in October last year, and we did a little speculating about what these machines might look like in terms of feeds and speeds. We frankly have not heard as much about the Zeppelin system, which is related to – but not the same as – the four-way nodes used in the Fleetwood system.
The word on the street is that IBM is planning on launching both of these machines at the same time rather than spread them out over two separate announcements. That does not necessarily mean that the machines will be generally available at the same time, however, so don’t jump the gun on that.
What I hear from people who are familiar with IBM’s plans is that the announcement will be going down on August 7, which is a little more than a week from now and which is not pegged to any particular IBM event as far as I can tell. We hear that the Zeppelin Power E950 will be available either on that day or on August 17, replacing the Power E850 four-socket box that launched way back in May 2015 with the Power8 processor – and notably without support for the IBM i platform. We have been a bit grumpy about this, and it is clear that IBM really just wanted to upsell IBM i shops on a single node of the Power E870, which is more expensive in terms of hardware and systems software, when they needed more than two sockets. We see that IBM and its software partners want to make money from big shops and not have them downshifting to smaller systems. But downshifting to smaller systems is what the industry does. There is a movement toward single-socket machines in some datacenters these days for this very reason, when you can get 28 or 32 cores in a single-socket X86 machine.
The Power E950 midrange box is expected to either ship on August 7 or on August 17 – we have heard two different rumors. And we have also heard that instead of making Power E970 line that scales to one or two four-socket nodes with unique processor features from the Power E980, which scales higher to three or four nodes – this is the pattern that IBM had with the Power8-based Power E870 and Power E880 and their “C” cloud-enhanced variants – that IBM would just give up on the Power E970 classification and just use the Power E980, thereby simplifying its own life and that of its customers. We are hearing that IBM will be able to ship Power E980 machines with one or two nodes on September 21, and that it will take until November 16 to start shipping machines that can scale up to three or four nodes. Some of the I/O enhancements related to these machines that use the “Cumulus” Power9 chip will roll out in the third or fourth quarter.
Both of these machines will be using buffered memory, but apparently in slightly different forms. The Power E950 will use industry standard memory sticks and have the Centaur memory buffer chip installed on a riser card that these memory sticks plug into and that in turn has connections to the Power9 memory controllers through the system bus. We expect a bunch of different processor features with various core counts, with the clock speeds going down as the core counts go up, something that the laws of thermodynamics demand because Dennard scaling is dead. We do not know if IBM is going to offer upgrades from Power E850 and Power E850C machines launched with Power8 iron to the new Power9 four-way system. We also do not know if IBM i is going to be supported on the Power E950, but Robert Plant has suggested that when the levee breaks, there is going to be hell to pay. So maybe IBM should reconsider and make IBM i a peer to AIX and Linux again on real four-way machines, not just a more expensive quarter of a Power E980 machine.
As for the Power E980, this machine, as we have pointed out, IBM has promised to offer upgrades from the Power E870 and Power E880 systems (including those C variants that came out in 2016) to Power E970 and Power E980 machines. Well, we don’t think there is a Power E970, but you get the idea. We have heard that the Power8 and Power9 big iron machines use the same DDR4 CDIMM memory sticks, with the Centaur buffer put right onto the DIMMs instead of on a riser card, and that means those customers who moved to DDR4 memory on their Power E870 and Power E880 machines (again, including those C variants) can move their memory sticks over to a Power E980 with no fuss and no muss – and without having to buy all new memory, which would be very expensive indeed. This will no doubt help cushion the blow of the cost of an upgrade to a Power E980.
As far as we know, the Power E980 will support IBM i as well as AIX and Linux. We will try to gather up more details in the meantime, and we will of course provide full coverage in the aftermath of the announcements, if they happen on August 7 or some later date. Stay tuned.