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Thread ID: 33114 2003-05-07 09:24:00 Single or double sided SDRAM? Mike (15) Press F1
Post ID Timestamp Content User
142131 2003-05-07 09:24:00 My dad wants to buy some SDRAM for his computer... But some RAM is single sided and some double sided... what's the difference? Which should he buy, and why? There seems to be quite a price difference between the two.

Mike.
Mike (15)
142132 2003-05-07 09:46:00 I think older motherboards need the double sided where as newer motherboards can use either. If the shop is good they'd probably let you take one and bring it back if it doesn't work properly. -=JM=- (16)
142133 2003-05-07 10:31:00 > I think older motherboards need the double sided
> where as newer motherboards can use either. If the
> shop is good they'd probably let you take one and
> bring it back if it doesn't work properly.

Interesting - someone told my dad that new motherboards need double-sided, and old computers use single sided... that sounded interesting to me, cause I thought new motherboards took the longer DDR RAM.

Mike.
Mike (15)
142134 2003-05-07 11:38:00 actually new or old both take double sided and single sided. it all comes down to how mauch ram per bank it can take. for eg old pc may have a limit of 128 per side so needs double sided 256 to get 256 ram. new pc can handle 512per side so only a singlesided 256 will be required. this is very roughly put but you hopefuly you'll get the idea.

and yes most new mobo's use DDR. you will see DDR labeled as SDRAM as DDR is actually a form of SDRAM. thers a few end of lines of PC133 SDRAM mobo's still on sale but basicly they are obsolete.
tweak'e (174)
142135 2003-05-07 11:46:00 > actually new or old both take double sided and single
> sided.

Thats not what I understand. Old motherboards used the single sided RAM, and as such all chips had to be installed in pairs. It was not physically possible to install only one memory stick Now however motherboards use double sided RAM, and as most people are aware you can quite happily install only one stick.

Entirely possible Im wrong, anyone clarify?

Iain
Iain Walmsley (3372)
142136 2003-05-07 11:57:00 provided you are only taking about SDRAM and not EDO you are completly off the mark .

the only ram that needs to be installed in pairs is the old EDO (for very old pc's) or RDRAM .
tweak'e (174)
142137 2003-05-07 12:04:00 That was with the really old stuff, EDO (early pentium) & fastpage (late 486) which needed to be in pairs .

With SDRAM, single/double sided refers to wether there are chips on both sides of the stick itself .


Mike, double sided will work in both, but it will be harder to find & more expensive because there will be more indvidual chips on it (usually 8 per side) . If you have to you can stick a higher density stick in it & use whatever it can read .

How old is the computer?

BTW, I hope those CDs survived their trip north .
bmason (508)
142138 2003-05-07 13:14:00 Weeeeell ?:|

Speaking from experience, I have an older A-trend MB that was suitably rated for memory size etc, but could only read 128 MB of a single sided 256MB stick . I replaced it with double sided and away she went .

Before I sent it back, I took a good look at the RAM connections and compared to double sided, there didn't seem to be enough for my MB to address that much RAM from only one set of connections .

I decided that it was an addressing issue and double sided worked fine . Since double sided is older technology and single sided make use of the higher density of memory that can be achieved in more modern chips, in most instances I'd put my money on an inability to access sufficient address lines .

I could be wrong too, but the shoe fits .

Cheers

Billy 8-{)
Billy T (70)
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