The new Intel® Xeon® processor C5500/C3500 series are the first Intel® Xeon® processors with integrated PCI Express 2.0—and the first with integrated storage features—making these chips a great fit for high-density systems including wireless infrastructure, routers, IPTV, military, security, VoIP, NAS, and SAN.  The increased integration can dramatically reduce chip counts, replacing as many as five chips with just two.  The processors also boast large gains in power efficiency, in some cases nearly doubling the performance-per-watt of past solutions.  In this blog we’ll review the new features, reveal some early benchmarks, and highlight embedded boards and modules based on these parts.


Let’s start with a quick overview of the processors.  As shown in Figure 1, the Intel Xeon processor C5500/C3500 series scales from a single-core, 23-watt processor to a quad-core, 85-watt processor, all using the same socket. These TDP numbers represent a major advance in power efficiency.   Compared to the older Intel® Xeon® processor 5500 series, the new chips offer a TDP reduction of at least 27 watts.   The Intel Xeon processor C5500/C3500 series compares even more favorably with the Intel® Xeon® processor 5400 series, boasting an up to 1.9x increase in performance-per-watt.



Figure 1. Intel Xeon C5500/C3500 processors and Intel Xeon 3420 chipset.


The biggest new feature in the Intel Xeon processor C5500/C3500 series is the integrated 16-lane PCI Express* 2.0 (PCIe 2.0) controller, which has a throughput rate of 1GB/sec.  This controller allows expansion cards to connect directly to the processor, rather than going through an I/O hub.  The Intel Xeon processor C5500/C3500 series also integrates new storage features including:


  • Non-transparent bridging (NTB) support for redundant systems
  • Asynchronous DRAM Self-Refresh (ADR) to preserve critical data in RAM during a power fail
  • Hardware-based RAID engine to offload RAID calculations from the core


Taken together, these new features make it possible to eliminate the I/O hub, bridge, and custom ASIC, potentially bringing the total board chip count down from five to just two.  The space savings is a major plus for high-density applications, particularly those that rely on the space-constrained AdvancedTCA* form factor.


The non-transparent bridging (NTB) logic enables high availability by connecting two independent storage systems over PCI Express. NTB allows each of the connected systems to access the other’s memory window.  This access supports failover by allowing one system to continue operating on the shared data after the other fails.  For a detailed discussion of NTB and its use, see the white paper Intel® Xeon® Processor C5500/C3500 Series Non-Transparent Bridge (PDF).


Reliability is also the motivation for the Asynchronous DRAM Self-Refresh (ADR) feature, which protects against data loss due to power failure. The feature detects a power failure as its happening, enabling memory controller sequences to finish and forcing the system memory to perform a self-refresh before shutting down.  Integrating this feature into the CPU saves cost by eliminating the external logic that would otherwise be needed to perform these functions.


The memory controller also offers remarkable memory performance gains compared to pre-Nehalem Xeon processors.  To illustrate the gains, Trenton Technology benchmarked the Intel® Xeon® EC5500 against the non-Nehalem Intel® Xeon® E5400 using the SiSoftware Sandra 2010 memory bandwidth benchmark test.  As shown in Figure 2, Trenton found that overall memory bandwidth performance increased by approximately 440\%.  (For tips on maximizing memory performance in the Intel Xeon processor C5500 series, see the Intel Embedded Community and Kingston Technologies’ white paper.)





Figure 2.  Memory benchmark results for a Xeon E5440 system with Intel® 5000P Chipset (left) and Xeon EC5500 system (right) demonstrate the advantages of the integrated memory controller.


Last but not least is the new RAID controller, which can configure disk drives in an array as a RAID-5 or RAID-6, protecting against single- or dual-disk failure, respectively.  RAID-5 and RAID-6 algorithms are compute-intensive, so the integrated controller includes XOR and P+Q accelerators that offload the processor.  These accelerators eliminate the need for a custom ASIC to perform RAID 5 and 6 operations.  Another advantage of using the integrated RAID engine is that the processor does not need to read and write all of the storage data, which maximizes the processor cache efficiency.


While we are on the topic of storage, it is worth noting that the Intel Xeon processor C5500/C3500 series supports the Storage Bridge Bay (SBB) specification.  The SBB spec allows control boards to plug directly into storage arrays, allowing for a denser architecture. (Prior to SBB, storage controllers required a separate blade slot.)


The Intel Xeon processor C5500/C3500 series is available in wide range of embedded boards and modules.  Examples include:


  • The Caswell CAR-5000, a two-socket, 2U rack mount network appliance intended for such high-performance networking applications as Universal Transverse Mercator (UTM), anti-virus, firewall, Virtual Private Network (VPN) and content filtering.
  • The Gigabyte GA-7JASV is a common ATX size motherboard designed for networking servers and other communications systems.
  • The Kontron AM5030 is a double-wide, full-size AdvancedMC* module designed for dense server environments deployed in storage, military/aerospace and communications networks.
  • The Lanner FW-8910 is a 2U rack mount dual-CPU appliance intended for the performance segment of the network security, Network Admission Control (NAC) and WAN acceleration market segments.
  • The Trenton JXT6966 is a PICMG* 1.3 System Host Board (SHB) for use in compute-intensive embedded, military/defense, medical imaging and communication system designs.


I’m excited to see how designers will use these new solutions.  How about you?  What will you do with the increased density made possible by the Intel Xeon processor C5500/C3500 series?


Kontron is a Premier member of the Intel® Embedded Alliance.  Lanner Electronics Inc. is an Associate member of the Alliance.  Trenton Technology, Inc. is an Affiliate member of the Alliance.  Caswell and Gigabyte are General members of the Alliance.



Kenton Williston

Roving Reporter (Intel Contractor)

Intel® Embedded Alliance


Embedded Innovator magazine