IDF: turbo mode for Nehalem
In his keynote speech at Intel's developer forum, in addition to setting out time scales and giving some initial details, Pat Gelsinger, head of Intel's Digital Enterprise Group, also provided a few benchmark results for Intel's forthcoming processors. He also talked about a previously unpublished feature of the next generation of core processors – codename Nehalem, a feature previously known as burn-in mode or Foxton – for Itanium. Now known as "turbo mode", Intel's Nehalem processors will, in moderation, support overclocking. The processor's numerous thermal cut-outs ensure that it automatically underclocks if it overheats, thus ensuring that no damage can occur. The processor will be able to up its clock speed to a maximum of one class higher, i.e. to the speed of the next fastest processor.
Gelsinger showed benchmark results for the 6-core Dunnington – Xeon 7400 series – processor, based on the Penryn core with FSB and external memory controller, which is expected next month. Dunnington also has a shared 24 Mbyte L3 cache. In IBM's 8 processor x3950 M2 system, which has a total of 48 cores – Xeon 7460, it became the first to achieve the million mark in the TPC C transaction benchmark for x86 systems, achieving precisely 1.200632 million tpmC. Its smaller Dell PowerEdge R900 System colleague, with four processors and 24 cores, achieved 634,825 tpmC in the Intel Caneland platform. 2.6 GHz Dunnington computers also set new standards in other benchmark tests for 4 socket systems, achieving 277 SPECint_rate2006 or 531,669 bops in SPECjbb2005 and 671.4 tpsE in the TPC E benchmark.
The Nehalem family will initially debut in the form of the i7, a high-end desktop processor – Bloomfield, and DP server – Nehalem EP, Gainsfield processors. Havendale and Lynnfield, intended for the larger desktop market, are planned for the middle of next year, where Havendale will, as well as a CPU, also have a graphics chip on board. There will also be parallel mobile versions, Auburndale – with graphics – and Clarksfield. The eight-core Nehalem EX – Beckton – for larger MP servers is also in the pipeline.
Thanks to the integrated memory controller and three DDR3 channels, the i7's memory performance is around three times better than predecessors with Penryn cores. One of the new features which Nehalem has inherited from the Pentium 4 is hyper-threading This has been implemented far more effectively than in the Pentium 4, so that most multi-threading applications will genuinely benefit from it – by between 7 – SPECint rate2006 – and 34 per cent – 3D PCMark Vantage CPU. A further innovation is VT-d I/O virtualisation. Using a SPECjbb2005 benchmark running in a VM, VMware demonstrated live on stage that VT-d can accelerate this benchmark by up to 80 per cent.
For more on the Autumn IDF 2008 see also:
- IDF: Intel firms up Nehalem plans
- IDF: Fast SSDs
- IDF: Future Xeon servers with extended power management
- IDF: the dual-core Atom for cheap computers is on its way
- IDF: Details about QuickPath Interconnect