IBM Rolls Out The Big Power8 Iron
October 6, 2014 Timothy Prickett Morgan
Customers looking to boost the capacity of their existing enterprise-class Power Systems servers got some reprieve late last week when ahead of the Enterprise2014 conference in Las Vegas IBM did a surprise launch of the E870 and E880 servers. The machines are follow-ons to the existing Power 770+ and Power 780+ machines and borrow technologies from the Power 795 announced four years ago.
The resulting E870 and E880 systems are designed to take the modularity that has been inherent in the Power Systems line since the Power5 machines were announced a decade ago and merge it with the high-end NUMA clustering and resiliency features that have always set the Power 595 and Power 795 machines apart.
With these enterprise-class machines, IBM uses non-uniform memory access (NUMA) clustering to create a shared memory system that spans from one to four server nodes and that presents a single image to the hypervisor or operating system. The Power 770+ has sixteen sockets and offered up to 64 cores and the Power 780+ had the same number of sockets and doubled that up to 128 cores; both machines topped out at 4 TB of main memory. There is a primary node in the system and PCI-Express peripheral slots are in the server nodes.
The Power 795 was based on the eight-core Power7 processor and up to 32 sockets could be lashed together to create a monster machine with up to 256 cores and 16 TB of main memory in its fully configured setup. The Power 795 had a midplane that included service processors, clocks, and oscillators as well as enough space to allow for the memory capacity to grow very large.
As The Four Hundred has discussed in past issues, with the Power8 processor, IBM has increased the NUMA ports on the processor used for so-called scale-up machines, and this improved on-chip interconnect allows for IBM to create a sixteen socket server without having to add any auxiliary chipsets while also improving the performance of that interconnect. The next result, in short, is that IBM can deliver a 16 socket server using the on-chip interconnect, and with the Power8 delivering about twice the raw computing oomph as the Power7+ chip, it can create a 128-core E880 system with four nodes that has about the same performance as the Power 795. By jacking the E880 system up to 192 cores, which IBM plans to do, the resulting machine will have about 40 percent more aggregate processing capacity than the Power 795, I estimate. (As we go to press, the details on this system are a little thin, and I get the distinct impression that IBM was not quite ready to fire off this set of Power8 announcements.)
The E870 has two 5U enclosures that have four sockets each. The system uses single-chip Power8 processors with either eight or 10 cores out of the 12 working. The E870, product number 9119-MME, has one version that uses an eight-core Power8 chip that runs at 4 GHz. The system has up to 512 GB of DDR3 main memory using IBM’s own custom DIMM (cDIMM in the IBM lingo) memory cards, which sport 16 MB of L4 cache memory on their “Centaur” memory buffer chips, per socket. That gives a maximum of 64 cores across two nodes and eight sockets, with a maximum memory of 4 TB. Another version uses a ten-core Power8 scale-up processor with 10 cores that runs at 4.19 GHz and that delivers a maximum of 80 cores across its eight sockets. This machine also tops out at 4 TB across the two nodes and four sockets. But Steve Sibley, director of worldwide product management for IBM’s Power Systems division, says that it will double up the memory to 8 TB, or 1 TB per socket, in the second quarter of 2015 for both E870 models.
Between the two nodes in the E870 is a 2U enclosure that has the goodies from the Power 795, all updated and modularized, on a virtual midplane that has field service processors, Hardware Management Console (HMC) ports, master system clocks and oscillators for controlling the timing of the system, an operator panel, and what is called a vital products data (VPD) card. The clocks, service processors, HMC ports, and power supplies in this system control unit are all redundant. NUMA/SMP cables are used to lash the nodes together, as with the prior enterprise-class machines, and another set of cables links the nodes into the clocks and service processors that are used to synchronize the whole shebang.
The Power E880, product number 9119-MHE, doubles the scalability up from one to four of those 5U nodes and has the same single system control unit in the center of the machines. One model has an eight-core Power8 chip that spins at 4.35 GHz and deliver a maximum of 128 cores; each of the sockets in this version can already max out at 1 TB per socket unlike the Power E870. (It looks like IBM is having trouble making its super-dense 128 GB cDIMM cards.) The biggest, baddest Power E870 has the full-on 12-core Power8 chip running at an as-yet unannounced clock speed, spanning 192 cores in a single system image with up to 16 TB of main memory.
At the moment, only the Power E870 machines with one or two nodes and the Power E880 with one or two nodes and using the eight-core chips are available. (The precise shipment date was not revealed last Friday when IBM put out the announcements.) That means the biggest E880 you can get today has 64 cores across two nodes and the biggest E870 is the 80-core version. In 2015, IBM will scale up the entry E880 with that eight-core chip so it can span the full 128 cores in four nodes, and the 48-core nodes spanning from one to four nodes, for between 48 and 192 cores, will also be available in 2015.
Speaking very generally, Sibley said that the Power E870 is supposed to be a replacement for the Power 770+ at about the same price point with somewhere between 35 and 40 percent more performance. Entry prices are expected to be around $120,000 for a reasonably configured entry system.
A lot of the technical specs of the Power E870 and E880 machines–performance ratings on the Commercial Workload Performance (CPW) test used for IBM i, pricing, and so on–were not available as we went to press. So we will chase the details down and follow up. Stay tuned.