I face a performance problem on Embest SABRE Lite board. I suspected a memory bandwidth limitation so I ran bw_mem from lmbench suite.
I have also a Boundary Devices SABRE Lite board. Here are the results with bw_mem -P 1 -N 4 128M what
| what | rd | wr | rdwr | cp | fwr | frd | fcp | bzero | bcopy |
| Embest | 507.76 | 306.41 | 195.14 | 204.25 | 2034.81 | 257.64 | 210.23 | 2033.10 | 212.76 |
| Boundary Devices | 621.20 | 378.51 | 287.07 | 284.16 | 2253.68 | 406.55 | 307.79 | 2246.99 | 308.64 |
The tests clearly show memory bandwidth is significantly lower for all use cases.
I have noticed the memory controller settings are different by displaying the register contents with U-Boot. However, both boards have the same Hynix DDR chip Hynix H5TQ2G63DFR with same speed grade H9C.
Does someone have an idea about this?