Re: Please Advise: SCSI vs. IDE

Albert Cahalan (
Mon, 30 Sep 1996 19:14:13 -0400 (EDT)

> With ISA busmasters, the kernel has to double-buffer the IO memory for
> the 16MB+ area, which makes the whole idea with DMA fail completely.
> The extra copy is _worse_ than the CPU doing the reading by hand in
> the first place.

That should not happen if the kernel was compiled with the 16 MB RAM
limit. Until I grepped the kernel source, I thought that config option
would get rid of the double-buffer overhead.