Nehalem and XIV Gen-3

XIV Gen 3 modules are built on a new generation of Intel microprocessors based on the Nehalem micro-architecture. Nehalem is the most profound architecture change that Intel has introduced in the 21st century.  Some of the key changes and their benefits are:

  1. Integrated memory controller: The memory controller now sits on the same silicon die as the processors. It runs at the same clock-speed as the processors instead of at the lower speed of an external front-side bus.  This dramatically improves memory performance and therefore overall system performance.
  2. No need for buffered memory:  Previously, buffered memory was required to improve the performance of the memory sub-system. Buffered memory is relatively expensive and energy hungry. With the faster Nehalem integrated memory controller, the system can deliver improved performance without needing buffered memory, saving cost as well as energy. XIV Gen 3 will be faster and cooler at the same time using unbuffered DDR3 RAM. And since the memory is cheaper, we can put more in.
  3. Increased memory capacity:  Nehalem supports more memory chips at higher speeds. In XIV Gen 3 this translates into a 50 to 200% increase in system cache, significantly lifting the performance headroom of an already stellar performer.
  4. No more front-side bus:  Memory, second CPU package and peripherals no longer have to share and wait on a single bus to communicate.  The connections are now direct or switched, enabling increased parallelism and the ability to do more work simultaneously.
  5. PCI Express Generation 2:  The I/O sub-system doubles in speed with the introduction of PCI Gen-2.   This enables faster network and I/O adapters for XIV Gen 3:
    – 8 Gbps fibre-channel host connections.
    – More iSCSI host connections (including at the entry configuration of 6 modules)
    – M
    ulti-channel, low latency infiniband as the inter-module connection.
    – A slot for solid state disk (SSD).
  6. Better systems management instrumentation: The system supports increased monitors for sub-systems for more sophisticated self diagnostics and healing. Remote management capability has also been improved.
Furthermore, the new motherboards have additional expansion capacity (more processors, memory and I/O) that can be utilized to deliver future improvements in performance and increased software functionality.

XIV Gen 3 is not the first storage sub-system to adopt the Nehalem architecture.  Some of our competitors (EMC and NetApp for example) have already done so with their dual-controller arrays. XIV Gen 3 takes the Nehalem architecture advantage forward, not twice, but six to fifteen times.Many thanks to Patrick Lee for writing up this great summation.


About Anthony Vandewerdt

I am an IT Professional who lives and works in Melbourne Australia. This blog is totally my own work. It does not represent the views of any corporation. Constructive and useful comments are very very welcome.
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5 Responses to Nehalem and XIV Gen-3

  1. Pingback: Nehalem and XIV Gen-3 - The Business of IT Storage Blog - IBM Storage Community

  2. MJG says:

    XIV Gen 3 is definitely lifting the performance of an excellent platform and will go along way to push it in to areas where customers were concerned (legit or not) about performance scalability.
    Is the SSD on a internal PCIe slot and not consume a 3.5″ disk slot?
    How big will the SSD layer be and will it be treated as a automatic Layer 2 cache behind the memory on each node?

    • avandewerdt says:

      Great questions.

      1) The SSD will use an internal PCIe Gen2 slot. The slot is around the back of the module (not the front). The SSD can be added and removed without opening the module or turning the module on or off.
      So it will not use a disk slot at the front (thus each module will continue to have 12 x 3.5 ” drives).
      2) Each SSD will be 500 GB in size and will be used for read cache. So 15 x 500 = 7.5 TB of extra read cache.
      3) The exact mechanics of how it will work have not yet been published, watch this space.

  3. KKBS says:

    In the spring 2011 we bought an XIV gen 2 with 2 TB disk, but with all the changes between gen 2 and gen 3, it does not look like a upgrade is possible, as we were told it would be :-(

    • avandewerdt says:


      There are only two things that I can see that are common between Generation 2 and Gen3.
      These are the UPSs and the ATS.

      The disks, modules, rack and switches all change. Upgrading is thus impossible.
      If an IBMer made such a promise you need to go back to them or their management and detail your concerns,
      because there was never a statement of intention from IBM that a Generation 2 machine could be upgraded to Gen3.

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