There are total four dedicated and one shared (with FFTA accelerator) MDMA streams supported by ADSP-SC58x/ADSP-2158x processors. These are as follows:
MDMA0(8→9) and MDMA1(18→19): Both of these streams run in SCLK0 domain and have bus width of 32 bits. Thus, the maximum theoretical bandwidth they can support is 112.5*4 = 450
MB /s.
MDMA2 (39→40): This MDMA stream runs in SYSCLK domain and has bus width of 32 bits. Thus, the maximum theoretical bandwidth it can support is 225*4 = 900 MB /s.
MDMA3 (43→44): This MDMA stream runs in SYSCLK domain and has bus width of 64 bits. Thus, the maximum theoretical bandwidth it can support is 225*8 = 1800 MB /s.
FFTA0_TXDMA (41)→ FFTA0_RXDMA (42): This MDMA stream can be used only when FFT engine is disabled in the FFTA0_WCTL register. Similar to MDMA3, this MDMA stream runs in SYSCLK domain and has bus width of 64 bits. Thus, the maximum theoretical bandwidth it can support is 225*8 = 1800 MB /s.
Note that the maximum practical bandwidth for high speed MDMA is 1500 MB/s only.