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Memory Channel Scaling with Sandy Bridge-E - A Core i7-3960X Experience

Memory Channel Scaling with Sandy Bridge-E - A Core i7-3960X Experience

Test Setup

Test Setup Notes

The test setup is identical to that used in our review of the Intel Core i7-3960X processor. The memory kit used is two pairs of Kingston HyperX low voltage performance memory module kits. Each kit comprises two 2GB modules that are rated at 1600MHz with 9-9-9-27 timings at 1.35V. They are ideal as we are not interested in overclocking them beyond their rated frequency. As pointed out earlier , we will be using a pair of this kit to see how performance of our setup is affected by different memory channel modes, starting off with quad-channel mode and worked our way down to dual-channel mode.


Siler Motherboard and its Multi-Channel Mode Population Rule

The main supporting cast of test setup is the Intel desktop board, the DX79SI which is also known as 'Siler'. The board supports multi-channel mode which makes it an ideal candidate.


Changing Channels

We began running our slew of benchmarking software with the board in a quad-channel memory mode setup. After the completion of the test, we removed a single memory module from the corresponding DIMM slot until we whittle down the board to its final configuration, a dual-channel memory mode. Although the X79 platform supports a single-channel memory mode, we decided not to go with this anemic setup as it may not serve any practical purpose in a real-life computing environment.


Memory Channel Mode Population Rules

In the list below, we have stated how we populated the memory DIMM slots of the DX79SI to configure the channel mode of the test setup. For the quad-channel mode, we tested the memory modules at their rated clock frequency of 1600MHz as well as at 1333MHz. We wanted to see if there was any major impact on the benchmark scores from a change in memory frequencies. For the rest of the modes, we configured the BIOS to let them operate at their rated clock frequency of 1600MHz.

  • DIMM 1, DIMM 2, DIMM 3 and DIMM 4 (Quad-Channel Mode, ran at 1600MHz  and 1333 MHz)
  • DIMM 1, DIMM 2, and DIMM 3 (Triple-Channel Mode, ran at 1600MHz)
  • DIMM 1 and DIMM 2 (Dual-Channel Mode, ran at 1600MHz)


Test Setup

We installed our memory modules on our test system which has the following specifications:

  • Intel Desktop Board DX79SI (Intel X79 Express chipset), BIOS version 0280
  • 4 x 2GB Kingston HyperX DDR3-1600 (CAS 9-9-9-27) (Also run at DDR3-1333MHz)
  • Zotac GeForce GTX 260 (ForceWare 197.45)
  • Western Digital Caviar Black 1TB SATA 6Gbps hard drive (one single NTFS partition)
  • Windows 7 Ultimate 64-bit

The list of benchmarks used:

  • BAPCo SYSmark 2007 Preview (ver 1.06)
  • Futuremark PCMark Vantage (ver 1.03.1, 64-bit)
  • Lightwave 3D 9.0 (64-bit)
  • 3ds Max 8 (SP2)
  • Cinebench 11.5 (64-bit)
  • Handbrake 0.9.4
  • Futuremark 3DMark Vantage (ver 1.03.1)
  • Far Cry 2
  • Battlefield Bad Company 2