iMX257 USB controller performs better than that of iMX6Q

[sayan]

Hi,

According to my understanding from the chip specification of iMX6Q and iMX257, USB Controller of iMX6Q should perform better that USB controller of iMX257. 

But I see the opposite result. I am hunting for the reason behind this but clueless till now.

The CPU speed is one third in iMX257 as compared to iMX6Q. RAM is higher in iMX6Q board but still there is a drop in performance.

I wonder what component is responsible for this. 

Please share if you have any clue. 

Thanks in advance.

Regards,

Sayan Mukherjee

[igorpadykov]

Hi Sayan

according to my data i.MX25 USB OTG performance 10-15MB/s while i.MX6Q

about 20MB/s according to
https://community.freescale.com/message/353963#353963
and depends mainly by buses bandwidth priorities defined by bus arbiters

NIC-301/MMDC (i.MX6) and AHB Crossbar Switch (MAX) in i.MX25 case.

Best regards
igor
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

[sayan]

Hi igor,

Thanks for your reply.

I am sorry, I forgot to mention that I am measuring the speed in the Host2 port of imx257 which supports Full speed max. But still I am getting a higher performance in imx257 Host2 Full speed than imx6q Full speed.

I am  trying to investigate the cause but still there is no clue till now.

Regards,

Sayan