Intel Xeon E5-4600 v2 “Ivy Bridge” Processor Review

Many within the HPC community have been eagerly awaiting the new Intel Xeon E5-4600 v2 CPUs. To those already familiar with the “Ivy Bridge” architecture in the Xeon E5-2600 v2 processors, many of the updated features of these 4-socket Xeon E5-4600 v2 “Ivy-Bridge” CPUs should seem very familiar. Read on to learn the details.

Important changes available in the Xeon E5-4600 v2 “Ivy Bridge” CPUs include:

  • Up to 12 processor cores per socket (with options for 4-, 6-, 8- and 10-cores)
  • Support for DDR3 memory speeds up to 1866MHz
  • AVX has been extended to support F16C (16-bit Floating-Point conversion instructions) to accelerate data conversion between 16-bit and 32-bit floating point formats. These operations are of particular importance to graphics and image processing applications.
  • Intel APIC Virtualization (APICv) provides increased virtualization performance
  • Improved PCI-Express generation 3.0 support with superior compatibility and new features: atomics, x16 non-transparent bridge & quadrupled read buffers for point-to-point transfers

Intel Xeon E5-4600 v2 Series Specifications

Model Frequency Turbo Boost Core Count Memory Speed L3 Cache QPI Speed TDP (Watts)
E5-4657L v2 2.40 GHz 2.90 GHz 12 1866 MHz 30MB 8 GT/S 115
E5-4650 v2 2.40 GHz 2.90 GHz 10 25MB 95W
E5-4640 v2 2.20 GHz 2.70 GHz 20MB
E5-4627 v2 3.30 GHz 3.60 GHz 8 16MB 7.2 GT/S 130W
E5-4620 v2 2.60 GHz 3.00 GHz 1600 MHz 20MB 95W
E5-4610 v2 2.30 GHz 2.70 GHz 16MB

HPC groups do not typically choose Intel’s “Basic” and “Low Power” models – those skus are not shown.

More for Your Dollar – Performance Uplift

With an increase in core count, clock speed and memory speed, HPC applications will achieve better performance on these new Xeons. Depending on the choice of SKU, users should expect to see 10% to 30% performance improvement for floating-point applications (model-to-model) without spending more. Even greater speedups are possible by upgrading to the new 12-core Xeon E5-4657L v2:

  • Xeon E5-4620 transition to Xeon E5-4657L v2: 63% performance improvement
  • Xeon E5-4640 transition to Xeon E5-4657L v2: 50% performance improvement
  • Xeon E5-4650 transition to Xeon E5-4657L v2: 33% performance improvement

More for Less – Switch SKUs without a Performance Penalty

Rather than spending the same amount for more performance, some users may prefer to spend less to achieve the same performance they’re seeing today. Given the microarchitecture improvements in “Ivy Bridge,” you’re still likely to come out at least a few percent ahead at the same core count and clock speed.

Replacing Old Servers & Clusters

If your systems are a few years old, you may be able to replace several with a single new server. The AVX instruction set, introduced with the previous generation of Xeons, provides a solid 2X performance improvement by increasing the width of the math units from 128-bits to 256-bits. Combined with other improvements in Xeon E5-4600 v2, you will be able to achieve the performance of older systems using just a single core from the “Ivy Bridge” architecture.

Transitioning from “Sandy Bridge” E5-4600 series Xeons

Given the increased core counts & higher memory speeds, lower-end Xeon E5-4600 v2 processors may replace older Xeon E5-4600 processors with improved aggregate performance.

Rather than increasing clock speeds for all “Ivy Bridge” SKUs, Intel has decided to offer some of the E5-4600 v2 processors with more cores but at a slightly slower clock speed. Specifically, the eight-core, 2.3GHz E5-4610 v2 (vs the six-core, 2.4GHz E5-4610) and the ten-core, 2.2GHz E5-4640 v2 (vs the eight-core, 2.4GHz E5-4650). Increased core counts, improved memory speeds, and Turbo Boost capabilities nearly always result in superior server performance.

Comparisons of note include:

  • Xeon E5-4610 v2 delivers additional value over Xeon E5-4610:  the new CPU has 33% more cores and faster memory at the same cost, but also a slower clock speed (a disadvantage only for poorly-threaded applications)
  • Xeon E5-4620 transitions to Xeon E5-4610 v2: same core count, but a faster clock speed and faster memory at a lower cost
  • Xeon E5-4640 v2 delivers additional value over E5-4640: 25% more cores and faster memory at the same cost, but also a slower clock speed (a disadvantage only for poorly-threaded applications)
  • Xeon E5-4650 transitions to Xeon E5-4627 v2: Same physical core count, but faster memory and clock speed at a much lower price point. Caveats include a slower QPI speed and no hyperthreading, the latter of which is of lesser importance to HPC.

Intel’s strategy with these CPUs makes sense, since four-socket systems tend to run software that takes advantage of higher core count more than higher clock speed.  Sacrificing 100MHz or 200MHz for two extra cores is almost always going to be a very favorable exchange.

Surprising Benchmark Performance Results

Despite some of the caveats mentioned above, the performance results achieved so far have been quite impressive. Benchmark numbers for the industry-standard floating-point SPEC fp_rate2006 suggest that even the modest Xeon E5-4610 v2 CPUs will stand up against the best of the dual-socket “Ivy Bridge” Xeon CPUs and the best of the previous-generation “Sandy Bridge” quad-socket CPUs.

SPEC fp_rate2006 results for Xeon E5-4600v2 compared with Xeon E5-4600 and E5-2600v2

Considering that a quad-socket server equipped with E5-4610 v2 is equivalent to the price of a dual-socket server with E5-2697 v2 and considerably less than a server with E5-4650 CPUs, we expect great success for this product line.

Greater Memory Bandwidth

Similar to what Intel did with the Xeon E5-2600 v2 series, memory performance is boosted across the board with Xeon E5-4600 v2 (Ivy Bridge):

  • Entry-level “Basic” CPUs now support 1333MHz memory
  • Mid-level “Standard” CPUs now support 1600MHz memory
  • Higher-end “Advanced”, “High Performance” & “Frequency Optimized” CPUs now support up to 4 DIMMs per socket at 1866MHz (in select configurations)

This 16-20% memory performance uplift for Xeon E5-4600 v2 is a critical performance boost for memory-intensive applications.

Special Note, Xeon E5-4627 v2 for CFD, FEA, and Multiphysics

Many CFD, FEA, and Multiphysics applications prioritize clock speed (least threaded areas), core count (well threaded solvers), and most of all memory bandwidth at once. The Xeon E5-4627 v2 SKU pairs the memory performance and core count of a 4-socket system with a high base clock speed. Previously, customers had to sacrifice one or the other.

Microway thinks this will be a winning combination for users whose models exceed the memory capacity of a 2-socket system. We anticipate extended discussion of this SKU with users of these applications.

Conclusion

As always, please contact an HPC expert if you would like to discuss in further detail. Intel has produced an Intel Xeon E5-4600 v2 Product Brief that’s available on our Knowledge Base. You may also wish to review our products which leverage these new Xeon processors:

For more analysis of the Xeon E5-4600 v2 processor series, please read:
In-Depth Comparison of Intel Xeon E5-4600v2 “Ivy Bridge” Processors

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