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

[Gregory Leblanc]

> -----Original Message-----
> From: James Lockwood [mailto:james at foonly.com]
> Sent: Wednesday, April 19, 2000 3:26 PM
> To: rescue at sunhelp.org
> Subject: Re: [SunRescue] Q: Regarding Sun Educator promo 
> Ultra 5 system
> 
> 
> 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

On a side topic, Intel LX based P-II motherboards often used EDO DRAM DIMMS.
Real pain in the neck to find, costs much more and is a bunch slower than
SDRAM.

> 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.

So, uhm, why are these machines using EDO ram?  Wouldn't SDRAM be a better,
faster, cheaper choice?
	Greg