2 Replies Latest reply on Aug 3, 2009 5:43 AM by Felix_M

    IOP34X RAM access speed issue (just 110Mbyte/s)

    Green Belt

      Hi All:

         I have memory read/write performance issue for a long time. 

         1) Use RAMSPEED to test memory

            The write speed is more faster than read.

            The worst speed of write is about 900MBPS(byte per second).

            The worst speed of read is about 130MBPS. 

         2) Use DD command or the test case writen by my self

            The write speed is about 490MBPS.

            The read  speed is about 240MBPS.

         3) By test driver to provide non-cached memory ranage to test read & write

            The write speed is same as read speed: 110MBPS.


        In IOP34X, memory bus is worked at 266MHz. And the DDR2 cell is 553MHz.

        if the memory access is non-burst access, it is maybe 110MBPS.


        In user manual of IOP34X, the Figure86 Supported DDR SDRAM Mode Register Settings:


      a. CAS Latency (tCAS) = 3, 4, or 5 for DDR2 based on the programmed setting in “SDRAM

      Control Register 0 — SDCR0”. Note, when ODT is enabled CAS Latency must be => 4.

      b. Burst Type = Sequential

      c. Burst Length (BL) = four


      What is Sequential?  INC4 or wrap 4?


      Best Regards


        • Who knows where can get right answer about IOP34X's memory performance
          Green Belt

          Hi All:

             I meet the memory performance issue. I can not get answer for a long in arm linux mail list and this community.

             Do I not describe clearful enough about this issue?

             Or There are no such issue on IOP34X? (Please give out the right result about memory test)

             or Intel has other community or technical support site to get the answer about this issue?

             or who can give me the contact of exports about this issue in intel.

            Best Regards


            • Re: Who knows where can get right answer about IOP34X's memory performance
              Felix_M BlackBelt

              Hi FredFan:


              Welcome to the Intel® Embedded Design Center Community. 


              Questions like yours are monitored by Intel technical representatives.  Please be patient as sometimes it can take some days for someone to review and respond to your question. 


              As the community moderator, I am not a technical expert on the IOP34X but from reading your question(s) I believe you have done a good job to explain the details of your situation.  If the Intel technicians need any additional information I am sure that they will ask you. 







              Message Edited by Felix_M on 08-03-2009 05:43 AM