[SunRescue] Q: Regarding Sun Educator promo Ultra 5 system

[James Lockwood]

On Wed, 19 Apr 2000 nick at ns.snowman.net wrote:

> The u5 (to the best of my knowledge) uses a thing called EDO Dimms.  EDO
> dimms are evil.  The only reason they were ever created is sdram failed to
> add something on the order of 2 pins so interleaving could be done.  This
> means that while sdram is faster 1 on 1, when you boost it up to 1 on 5
> (interleaved 5 times) or 1 on 10 (interleaved 10 times) sdram looses.

EDO DRAM predates SDRAM.  EDO was used to cut down on CAS latch time from
FPM.  SDRAM eliminates that latching interval per address (just bang on
RAS to get more bytes out), making it ideal for cache line refilling. 

You can certainly interleave SDRAM if you like.  Most PC motherboard
vendors seem to follow the school of thought of "cut costs no matter
what", and are therefore unlikely to handle it correctly.

-James