I am working with Wandboard DL with Linux 4.0.4 configured for SMP.
We have 4 DDR3 chips of 128Mb at 396MHz and a bus width of 32bits.
128M * 16 DDR3-1600 11-11-11
I think the maximum bandwidth is:
Channel Width ( bits/transfert) * speed (Transfert/second)
= 32 * (396Mhz *2 )
= 3168 MB/sec
I make some measures with dd.
I used the following commands:
mount -t tmpfs -o size=1024M tmpfs /tmp/mytmpfs
dd if=/dev/zero of=file.bin bs=1024k count=500
Measures show that the bandwidth for file access on the ram disk is 214.1MB/s.
There is a factor of 14.79 between calculate maximum bandwidth and measured bandwidth. (3168/214.1)
Do you think that’s correct bandwidth?
With maximum bandwidth of 3168Mb, which useful bandwidth can we expected?
Thanks in advance for your help