Can someone tell me the diff between Simm and EDO???

Well the title says it all... How can you tell the difference? Ive been reading through the classifieds and so many are looking for EDO. How do you tell the diff? I got into computers when that stuff was on its way out, so I never had to learn it.... I have alot of those older smaller sticks around here from SOO many different machines.... No clue about any of their details, but heck, if I can sell them all off as they are Im all kindsa game!~! LMAO

So, what do I have to do to tell the difference between them?~?

Allmost all EDO comes in the form of 72 pin SIMM's. Of course, you can have 72 pin SIMM's that are fast page RAM, which isn't quite as good. And there are a few EDO DIMM's out there. Sometimes there will be a sticker that says fast page or EDO on the SIMM. I don't think most of the pepople here would be too concerned about whether or not it's fast page or EDO, they just want something for a folding box.

Ok, huge bump here... I actually really need to understand this a little better. This is an exerpt from my new (well to me) mobos pdf manual. Anyone willing to explain what this means? Is DIMM and EDO the same? or? SIMM? anyone?

SIMM and DIMM have very specific meanings and they aren't particularly useful (in most modern hardware)

SIMMs have one edge with contacts on it

DIMMs have contacts on both sides

Self-correction ---- I could be sort of wrong there - maybe it's just that memory chips sit on both sides on DIMMS

In either case it's an external distinction. EDO and SDRAM work in a different way. I'm pretty sure that SIMMS came first and that DIMMS were an improvement to the EDO design, like EDO-II

I could be way off on this, but seeing that nobody else has come to your rescue, I'll throw in my 1 1/2 cents... In other words, don't quote me on the specifics.

EDO is usualy more expensive per MB because it is rare to find at retail - because there's very little market for it unless in huge (for it) sticks, like 32 or 64. AFAIK most EDO modules produced were in the 4-16MB range.

Ugmore Baggage said:

SIMM and DIMM have very specific meanings and they aren't particularly useful (in most modern hardware)

SIMMs have one edge with contacts on it

DIMMs have contacts on both sides

Self-correction ---- I could be sort of wrong there - maybe it's just that memory chips sit on both sides on DIMMS

In either case it's an external distinction. EDO and SDRAM work in a different way. I'm pretty sure that SIMMS came first and that DIMMS were an improvement to the EDO design, like EDO-II

I could be way off on this, but seeing that nobody else has come to your rescue, I'll throw in my 1 1/2 cents... In other words, don't quote me on the specifics.

EDO is usualy more expensive per MB because it is rare to find at retail - because there's very little market for it unless in huge (for it) sticks, like 32 or 64. AFAIK most EDO modules produced were in the 4-16MB range.

Click to expand...

DIMMS have over twice as many pins connecting to the mainboard and are 64 bit, meaning you only need one at a time. SIMMS are 32 bit. So for a Pentium system, you would need two at a time. I wouldn't really call DIMMS EDO-II though. There was no real improvement in the memory technology, just a different memory module type. If you haven't figured it out yet, the Pentium and later chips all use a 64 bit memory interface, compared to the 32 bit one of the 486 (where one 72 pin SIMM was sufficient). Note that there were also 30 pin SIMMS that were 8 bit (you needed 4 for a 486), but they're not relevant here.

EDO is not all that expensive. And the large sticks aren't over difficult to find. 128 MB EDO can be had for $18 on Pricewatch.

OK, well the motherboard I have must take EDO DIMM's then. It has presently 1 chip in it. Dual sided and is 32 in size.

Now if Im reading this right... SIMM's are one sided where DIMM's are dual correct?

The chip has a sticker still on it that has EDO.

So this would be EDO DIMM.

Any corrections?

No corrections, it is an EDO DIMM. DIMM stands for Dual Inline Memory Module, and as stated above, they have 168 pins. SIMM stands for Single Inline Memory Module, and they have 72 pins. EDO stands for Extended Data Out, it holds data for multiple reads at a memory address. SDRAM stands for Synchronous Dynamic Random Access Memory, it has a clock chip that synchronizes with the sytem clock ansd is used to synchronize the input and output signals. SDRAM is better, so you might try a stick in that board to see if it will work. (if you have some laying around) Some chipsets couldn't use SDRAM, so it may have to use EDO.

OK, excellent. I am actually starting to understand! lol

The guy I traded the mobo from said he tried to put sd in it and it wouldnt fit right. I might give it a try some time anyways... lol...

Excellent ~ I now know what I need to get.
Thanks for the help guys!

I've got a bag o' RAM at home with EDO SIMMS and DIMMS ranging from 8MB to 32MB...I may even have a 64 sitting around somewhere...then there's the 32KB RAM module that goes in the Timex Sinclair...

Just wanted to throw that in. Sounds like you've got it figured out.