DDR3L Write Performance

[kojimiura]

When executing the following command on U-BOOT The first time was 414msec and Please tell me why the second and subsequent times are so slow as 541 msec.

mw.w ffa00008 f; mw.l 01000000 0 4000000; mw.w ffa00008 0

　

(ffa00008　：　At the tp terminal of the PLD connected to the IFC bus
I measure time with an oscilloscope.）

[kojimiura]

I would like to know why there is a large difference in DDR write time (about 100msec) even though the purpose is the same mw command.
We are considering an application that processes within a fixed period of time (5msec), so this difference cannot be ignored.

[yipingwang]

Would you please let me know your purpose to do this experiment?

For DDR performance, we suggest you use Linux application "LMBench" to do testing.

[kojimiura]

I run LMbench.
I'll attach the results.
however,
There is no value in the Memory Write item.
I run everything by default Settings.
I would appreciate it if you could tell me how to measure memory performance using LMbench.

[yipingwang]

Please download QorIQ SDK 2.0 user manual from the following link.

https://support.nxp.com/s/case/5002p00002zp58BAAQ/community-ddr3lwrite-performance?language=en_US

Then refer to the section "12.1.4 LMBench" in this document.

[kojimiura]

Thank you.