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Thread ID: 43563	2004-03-19 01:35:00	Visual Difference between SD-RAM and DDR RAM	hamstar (4)	Press F1

Post ID	Timestamp	Content	User
223593	2004-03-19 01:35:00	I'm doing a hardware speech now for course (see other speech here (www.extremedevlopment.com)) and I can't figure out the difference between DDR and SD RAM. Yes, I know the technical difference, works on the up and down cycle etc etc, but what are the visual differences. I know (think) that either can be DIMM or SIMM (Single/Double Inline Memory Module) but are the pins arranged differently or something? Different notches amongst the pins? Or is it that SD is SIMM and DDR is DIMM? My DDR333 is SIMM in DIMM slots, so that theory doesn't work. Can anyone flatten this out for me? Cheers. .ham	hamstar (4)
223594	2004-03-19 02:58:00	Simms are 32 bits wide and dimms are 64 bits wide... SD Ram = 168 pins with two notches... DDR SD Ram = 184 pins with one notch... 486's only had a 32 bit wide date bus so they only needed to shift 32 bits at one time... hence 32 bits was wide enough... when the pentium came out with a 64 bit wide bus... the computer was having to do 2 clicks to get data from a "simm" to fill it they then built ram that was 64 bits wide to optimise the flow of data on a pentuim... hence "Dual inline memory module" are you shore you can get a 168 pin simm...???	00falcon (3801)
223595	2004-03-19 03:04:00	sorry... i ment 184 pin Simm... is your baby running dual channel DDR...???	00falcon (3801)
223596	2004-03-19 08:31:00	Did I say Dual Channel? I meant double dat rate, or double inline memory module (which is the ram with chips on both sides) Interesting about the 64bit part....	hamstar (4)
223597	2004-03-19 10:06:00	Yes, let's all hop on the front side bus for a trip down memory lane!	Growly (6)
223598	2004-03-20 01:55:00	The most obvious visual differnece is that the key slot(s) are in differnet locations, thats the little cut outs between the rows of gold ( on good ram ) or silver ( cheap ram ) pads.	ugh1 (4204)
223599	2004-03-20 02:08:00	SIMM/DIMM refers to the bus width (32 vs. 64bits), not the number of chips on the stick (which is just economics). The last type that used SIMMs were the old 72pin ones in 486s. Everything newer is DIMM.	bmason (508)
223600	2004-03-20 03:09:00	However, the "silver" isn't silver --- it's tin. The gold is gold. (Silver would actually be quite qood ... the oxide is conductive. But it's not as cheap as tin.)	Graham L (2)
223601	2004-03-20 03:13:00	Single sided stickes as aposed to double sided stickes . . . If you can . . . go single sided . . . double sided stickes are (i think) cheaper to produce . . . as it only takes half as many chips to produce the same number of megs . . . Double sided sticks are fine . . . but some north bridges just cant reconise them . . . electronicly they are seen the same by the puter . . . just some boards cant take double sided stickes . . . before i learnt this . . . i upped the ram in my baby . . . with a 256 ddr stick . . . double sided . . . and it worked fine . . . but i have seen a board that just wont take a double-sided stick . . . I dont know how common this is . . . so cant really comment . . . but i will from now on . . . try to keep to single-sided stickes Falcon	00falcon (3801)
223602	2006-10-15 16:55:00	SDRAM stands for Synchronous Dynamic Random Access Memory . DDR is short for "DDR SDRAM" and stands for Double Data Rate . Therefore, the main difference between SDR and DDR memory the doubled speed: DDR can transfer data at roughly twice the speed of SDRAM . For example, PC133 SDRAM runs at 133 Mhz, while 133 Mhz DDR effectively runs at 133 Mhz x 2 = 266 Mhz . SDRAM has 168 pins and two notches at the connector, which prevents it from being used in a DDR SDRAM motherboard and vice versa . It comes mainly in PC66, PC100 and PC133; the bus speeds of the RAM in MHz . DDR SDRAM has 184 pins and a single notch at the connector . It comes in speeds of PC1600 (166 MHz), PC1800 (200 MHz), PC2100 (266 MHz), PC2700 (333 MHz), PC3200 (400 MHz), and PC4400 (550 Mhz) . The numbers represent the theoretical maximum bandwidth of the DDR SDRAM in Megabytes per second (MB/s) . For example, PC2100 has a theoretical maximum bandwidth of 2100 MB/s .	nirmald (5419)
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