Intel releases new CPUs and NICs with nested page tables and I/O virtualization

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Yesterday Intel announced the availability of its new 45nm enterprise-class CPU: the Xeon 5500 series (codenamed Nehalem).

The new processor features a lot of much awaited components like:

  • an integrated memory controller
  • a new point-to-point processor interconnect (QuickPath Interconnect) that replaces the Front Side Bus (FSB)
  • the nested page tables technology (Extended Page Tables or EPT), part of Intel VT-x
  • the I/O virtualization technology (VT-d) that supports the VMware VMDirectPath technology
VMDirectPath_1 VMDirectPath_2


To highlight the performance improvement, VMware published three new benchmarks measured with VMmark that scores impressive results for three different two-socket systems (8 cores):

The best performance scored by a two-socket system before the ones above was just 9.15 with 7 tiles obtained with a HP ProLiant ML370 G5 and Xeon 5470 CPUs.

Also Citrix published some performance analysis of its XenServer running on top of Nehalem CPUs, reporting an improvement of 53%:


Along with Nehalem, Intel also released a new NIC, the 82599 10GbE, that features the I/O virtualization technology for networking components called VT-c.

The VT-c components included in this NIC are:

  • Virtual Machine Device Queues (VMDq) which improves performance and CPU utilization by offloading the data-sorting burden from the VMM to the network controller. Recent enhancements include offloading inter-VM switching within a server.
  • Virtual Machine Direct Connect (VMDc) which provides near-native performance by facilitating direct assignment of a virtual function on an Ethernet port to a VM.
    VMDc includes both Single-Root I/O Virtualization (SR-IOV) and VM mobility.