Hi,
In my Test [PCIe between 2 shannon] (MSMC to MSMC) using EDMA3 , i use the following parameters :
- PCIe Gen2: Transfer data rate = 5Gpbs/ lane.
- Used Number of lanes: Num_lanes = 2 lanes (2x)
- 20% reduction due 8b/10b consideration.
- Data size to transfert : 4MB
- Memory Write PCIe transaction
at first I was working with EDMA3 based on CSL , and i find 707 MBps for data size 4MB.
then I used the EDMA based SYS/BIOS examples that i found in the path below. when i mesure the throughput performance of data size 4MB , i find 1634 MBps !! (superior to the theory 819,2 MBps )
~\ti\mcsdk_2_01_02_06\edma3_lld_02_11_05_02\examples\edma3_driver\evm6678\sample_app
the ACNT parameter for both EDMA3 is 128 B.
conclusion : so for the same Data size 4MB , i find the following throughtput results :
- EDMA3 based on CSL : 707 MBps
- EDMA3 based on SYS/BIOS : 1634 MBps
the problem now is in throughput of EDMA3 based SYS/BIOS , because the theoretical speed is exceeded .
can you give me an explanation of this problem please ?!
thank you,
Sincerely,
Zakaria.