1. Computers
  2. Display Drivers
  3. Graphics Cards
  4. Memory
  5. Motherboards
  6. Processors
  7. Software
  8. Storage
  9. Operating Systems


Facebook RSS Twitter Twitter Google Plus


Phoronix Test Suite

OpenBenchmarking.org

Intel DDR2 FB-DIMM Performance

Michael Larabel

Published on 16 June 2006
Written by Michael Larabel
Page 1 of 12 - Comment On This Article

Intel was first to adopt DDR2 memory when they had launched their LGA-775 socket nearly two years ago with the Grantsdale and Alderwood Chipsets. Intel Corporation is first again to introduce the latest in memory technology: FB-DIMM. FB-DIMM is short for Fully Buffered Dual Inline Memory Module, and is primarily designed for mission-critical server environments that require maximum performance with minimal errors. FB-DIMMs are designed to bring the best traits from DDR2 memory while combining a new point-to-point serial memory interface. Some of the key benefits for Fully Buffered DIMMs include enhanced reliability, greater bandwidth, improved scalability, and higher capacity per memory channel.

The serial memory interface for FB-DIMMs allows a greater quantity of memory modules to be used, where a traditional system would fail. The weakness of conventional DIMMs is the dedicated connection with the memory controller, and the overloading of these connections with a high memory concentration. One of the notable factors for FB-DIMMs is the adoption of an AMB (Advanced Memory Buffer) chip. The AMB controls the transmission of memory data into packets. This process is similar to that of PCI Express, SATA, and other serial technologies. The AMB chip does communicate with the next succeeding chip through a bi-directional serial interface. Meanwhile, the first AMB chip in the channel is what communicates with the memory controller. The Advanced Memory Buffer should also make it an ease for these mission-critical servers to adapt new memory standards, such as DDR3, while using the same 240-pin interface and making no other upgrades.

Another benefit of FB-DIMMs is the lower pin count for the memory controller and easier routing of multiple channels across the motherboard due to the serial bus. The serial data path of this memory should provide faster performance over current DIMMs. FB-DIMMs are also immune from increasing latencies when the memory density increases. FB-DIMMs also utilize ECC (Error Checking and Correction), and incorporated into the modules is CRC (Cyclic Redundancy Check). On top of Cyclic Redundancy Check is also a bit-lane fail-over correction feature, which aims at locating and removing bad data paths.

Current limitations of this technology are each FB-DIMM channel can only contain up to eight modules, and only six memory channels are allowed per memory controller. Even so, that is a possible 48 FB-DIMMs per memory controller. Now some food for thought, with 48 FB-DIMMs each offering up 16GB of memory (which will soon be available), the total capacity would be 768GB. The governing body over semiconductor engineering standards, JEDEC, had only finalized the specifications for FB-DIMM last month.

Even with the memory being buffered and the Cyclic Redundancy Checking, FB-DIMMs are theoretically faster than traditional server memory, which is the focus of the entire article. Of the speed advantages include the bi-directional serial interface being able to read and write data simultaneously, greater number of memory channels, and more. We will be looking at its Linux memory performance in the server environment compared against existing DDR1/DDR2 desktop and server modules, as well as looking after the effective memory bandwidth when more memory channels are enabled.

Feel free to discuss this article in our Phoronix Forums.

Latest Linux Hardware Reviews
  1. Rosewill RS-MI-01: An Ultra Low-Cost Mini-ITX Chassis
  2. D-Link DCS-2330L HD Wireless Network Camera
  3. Gigabyte AM1M-S2H
  4. AMD's New Athlon/Semprons Give Old Phenom CPUs A Big Run For The Money
Latest Linux Articles
  1. Red Hat Enterprise Linux 7.0 RC Benchmarks
  2. AMD Catalyst 14.4 Brings Few Linux Performance Improvements
  3. The Performance Of Fedora 20 Updated
  4. Clang Fights GCC On AMD's Athlon AM1 APU With Jaguar Cores
Latest Linux News
  1. NGINX 1.6 Brings SPDY 3.1 & Other New Features
  2. Linux Foundation Announces A Core Infrastructure Initiative
  3. More Steam Linux Tests/Benchmarks Might Be Coming
  4. NVIDIA's Amazing Single-Board ARM Computer Might Be Delayed
  5. Fedora 21 To Get A Playground, New Features
  6. PC-BSD Is Developing Its Own Desktop Environment
  7. Valve Is Bringing VOGL To Windows & Working On Regression Tests
  8. Canonical Is Taking Over Linux 3.13 Kernel Maintenance
  9. Google Web Designer Is Now Natively Available On Linux
  10. Ubuntu 14.10 Is Codenamed The Utopic Unicorn
  11. Audacious 3.5 Lightweight Audio Player Released
  12. Steam Updated For Ubuntu 14.04 LTS, SteamOS
Latest Forum Discussions
  1. What Else Would You Like To See On Phoronix This Spring?
  2. HTPC-upgrade advice: AMD Richland A8-7600 or Kaveri A10-6700T ???
  3. Linux Kernel Developers Fed Up With Ridiculous Bugs In Systemd
  4. The GNOME Foundation Is Running Short On Money
  5. The Most Amazing OpenGL Tech Demo In 64kb
  6. Announcing radeontop, a tool for viewing the GPU usage
  7. New card. Open source drivers only.
  8. Script for Fan Speed Control