🚀 go-pugleaf

Your sales rep is incorrect, although not too badly.  
The cache in DOS is for disk read and writes.  It stores
often-accessed information in memory to speed up disk
i/o.

The cache on your motherboard (ie computer) does the same
exact thing except for MEMORY read/writes.  It stores often
accessed memory in the cache to speed up precessing time.
The cache ram is significantly faster than your conventional
memory, so the cache also frees up the computer from having
to wait for the memory to refresh (sidebar: it takes time to
write to memory; the system has to wait for the memory to catch
up, hence the "wait states" that some computers have to perform.
This just idles the processor for a cycle (after each cycle the
processor performs) to allow the RAM to catch up.  The 
cache alows the computer to run at less or zero wait states,
therefore allowing your computer to run as fast as it is 
capable of).

Hope this helps.  Someone else may have a clearer answer.

--
					Jason A. vanValkenburgh
					University of Virginia '95
					jav2d@virginia.edu