That is odd and rare. That must be some slow SRAM. The OS probably gives the SRAM a higher priority than chip ram as normal but it must be slower. You need ChipMemFirst for this 1200 
. Lot's of memory on the Amiga can actually be slower after it's fragmented unless running TLSF mem or similar. There is a longer memory list to transverse.
IIRC, PCMCIA bandwidth on the A1200 is something like 2-3MB/s, which is pretty damn slow even compared to chipram.
