explain EDO & FPM?

explain EDO & FPM?

Post by Teh Che » Thu, 28 Dec 1995 04:00:00



hi,

can anyone explain what fast page mode & extended data out (EDO) simms
are.  a technical overview would be nice.  i've seen people selling
EDO simms, but haven't seen anyone selling FPM.  what are the prices
like for FPM simms?

as far as linux performance goes, has anyone quantified what the
performance benefits are for either?

thanx
-t

 
 
 

explain EDO & FPM?

Post by Cameron L. Spitz » Sat, 30 Dec 1995 04:00:00




>hi,

>can anyone explain what fast page mode & extended data out (EDO) simms
>are.  a technical overview would be nice.  i've seen people selling
>EDO simms, but haven't seen anyone selling FPM.  what are the prices
>like for FPM simms?

Fast Page Mode is the signalling protocol used by the DRAMs that have been
standard in personal computers since the Apple ][.  It "goes without saying."

Extended Data Out is a minor hack to that protocol that makes a fast
cache fill burst cycle a little more practical.  It's a trivial
change to the DRAM chip; many manufacturers are using designs that
support both protocols and are "programmed" with one personality or
the other fairly late in the manufacturing process.
Nippon Electric (NEC) calls EDO "hyper page mode" but it's just another
name for the same thing.

Quote:>as far as linux performance goes, has anyone quantified what the
>performance benefits are for either?

It depends on whether your motherboard is able to take advantage
by running the cache fill in fewer clocks.  If it can, you might see
10% improvement doing operations that don't fit in your L2 cache.
If your motherboard isn't that fancy, or you didn't get the kind of
cache that can do the shorter burst, there will be no improvement.

EDO is taking a while to catch on because there are so many motherboards
out there that don't take advantage of it, and people are publishing
"benchmark" scores showing no improvement.  Also because the spot market
(where hobbyists buy RAM) is charging an absurd premium for the parts.

Cameron
--
http://www.rahul.net/cameron/

 
 
 

1. FPM parity versus EDO

I know this is probably a item that has been discussed here
before, but I missed it so I apoligize for asking.
Which is the better purchase FPM + Parity or EDO when it
comes to speed ?

Thanks for any info,

2. Modem won't fire up -- Newbie

3. FPM vs EDO memory for alphapc 164

4. CGI-File not found

5. FPM main mem mixed with EDO video mem

6. printcap clueless

7. Q: Memory upgrade issues (EDO vs non-EDO)

8. why does this not work?

9. Mixed EDO/non-EDO?

10. What difference between EDO DRAM and EDO parity RAM?

11. Will EDO work with non-EDO ?

12. EDO and non-EDO mix - no X?

13. Pentium, Triton, EDO, & Linux?