Which kind of memory gets high performance?OCRAM or SDRAM

[Gloss]

I attach a sdram( W9825G6KH-5i) to rt1176 via semc port by 16 pins.
And I'd like to know which kind of memory gets high performance.
The on-chip RAM or SDRAM on board.

[MultipleMonomials · Accepted solution]

In terms of memories, the ITCM and DTCM will be the fastest, because they run at the same speed the core does and don't use a cache.  OCRAM is slower (3-4x slower for memcpys, IIRC) since it has to go through the AXI bus and the cache.  SEMC probably cannot go faster than OCRAM (since it is using the same AXI bus and cache), but the exact speed will depend on the setup.