Best Practices

Why 1866?

The next generation of DDR3 has arrived. New chipsets and processors from AMD® and Intel® now support memory operating at 1866MT/s (aka 1866MHz). DDR3-1866 memory has a module classification of PC3-14900, which effectively means the peak data rate of the module is 14.9GB/s (see table). That’s approximately a 14-percent improvement on memory bandwidth over DDR3-1600.

Technology MHz Speed
(Data Rate)
Module Classification Module Peak Bandwidth
DDR3 (1.5V)
DDR3L (1.35V)
DDR3U (1.25V)
800 (DDR3-800) PC3-6400 6400 MB/sec. or
6.4 GB/sec.
1066 (DDR3-1066) PC3-8500
8500 MB/sec. or
8.5 GB/sec.
1333 (DDR3-1333) PC3-10600
10600 MB/sec. or
10.6 GB/sec.
1600 (DDR3-1600) PC3-12800
12800 MB/sec. or
12.8 GB/sec.
1866 (DDR3-1866) PC3-14900 14900 MB/sec. or
14.9 GB/sec.

In servers, the processor model number affects how fast the memory can operate. Higher model numbers support 1866MT/s but may be limited by the number of DIMMs per Channel that are installed or by the type of server/workstation motherboard.

Step 1 — Know Your System

Only the latest generation of chipsets and processors support DDR3-1866 memory.

  • Quad Channel Memory Architecture
    - Intel Xeon™ E5 v2
    - C600 Series Chipset
    - AMD Opteron™ 6300 Series

  • Available capacities at 1866MT/s are:
    - 2GB, 4GB, 8GB ECC DIMMs (Workstation/Server)
    - 4GB, 8GB, 16GB Registered ECC DIMMs (Server)

Step 2 — Maximize Server Memory Performance

New Xeon E5 v2 and AMD Opteron 6300 servers support up to 1 DIMM per Channel (see table).

Xeon E5 v2 / AMD Opteron 6300 1.5V
Module Type Module Ranks
1 DIMM per
Channel (1 DPC)
2 DIMMs per
Channel (2 DPC)
SR/DR 1866 1600
Step 3 — Determine the memory bandwidth for your applications
  • DDR3-1866 effectively increases bandwidth over DDR3-1600 by approximately 14 percent.

  • Quad Channel architecture such as those supported on Xeon E5 “v2” and Opteron 6300 platforms increases memory bandwidth by up to 35% over previous Triple Channel architecture.

  • Some applications may require the maximum memory bandwidth available, such as 3D applications, CG, CAD and mechanical/industrial design, technical and scientific computing, digital content creation and video games.

        Back To Top