2

I am looking at a dual socket server based on the Intel(R) Xeon(R) CPU E5-2640 v3 @ 2.60GHz

The configuration looks like this.

  • 4 memory channels per socket

  • DIMMs are 8x32 GB DDR4 2133/1866 modules per socket.

JEDEC says DDR4/1866 peak transfer rate is 14.93333 GB/s. Given that there are 4 memory channels, can I assume a (theoretical) memory bandwidth of 4x15 = 60 GB/s?

None of the benchmarks (single-threaded reads) I have gets close to that, they max out around 9 GB/s.

Citizen
  • 1,103
  • 1
  • 10
  • 19
Frank Astier
  • 21
  • 1

1 Answers1

0

Check this: https://www.intel.com/content/www/us/en/support/articles/000056722/processors/intel-core-processors.html

The theoretical maximum memory bandwidth for Intel Core X-Series Processors can be calculated by multiplying the memory frequency (one half since double data rate x 2), multiplied by the number of the bytes of width, and multiplied by the number of the channels supported for the processor. For example:

For DDR4 2933 the memory supported in some core-x -series is (1466.67 X 2) X 8 (# of bytes of width) X 4 (# of channels) = 93,866.88 MB/s bandwidth, or 94 GB/s.

Now, you should not expect 100% bandwidth utilization in most benchmarks - it would be around 70% down to 50%, for instance, dependending on how DIMMs are populated besides efficiency of memory controller.

Kovalex
  • 101
  • 1