RAM Bandwidth?

[dareck]

[IMG][/IMG]

The number circled in red (in the image attachment) is the RAM's bandwidth as reported by memtest?

How is that number attain by the software?
Would we have to run the full test to get the actual bandwidth?
And is the number usually significantly smaller as compared to the actual bandwidth (for the image above, the memtest was launched on a system with a DDR3L 1600MHz (128000MB/s) RAM.

[David (PassMark)]

As it is open source you can look into the code and see all the details. The code is in the memspeed() function. It is basically an x86 assembler language loop like this,
rep
movsl

But there are many different ways to calculate bandwidth. Our PeformanceTest software also has a function to do this, with a number of different options to play with.

You don't need to run all the tests to get the bandwidth figure, as the bandwidth figure is calculated just once at startup.

launched on a system with a DDR3L 1600MHz (128000MB/s) RAM.

I don't know where you got your 128000MB/s figure from, but it is about an order of magnitude wrong.