DDR vs SDR

[GiddyupGilbert]

I get the feeling DDR is newer and faster. I have a KM2M motherboard that will take 2 sticks of either DDR or SDR; cannot use both at same time. I currently have the 2 slots of SDR filled with 256 and I'm planning on upping that to at least 2 sticks of 512. Any input here greatly appreciated.
Thanks, Giddyup

[caperjack]

Advanced memory controller supports PC2100 DDR266 technology up to 2gig ,so that would mean you could add 2x1024

from this site !
http://www.msicomputer.com/product/detail_spec/product_detail.asp?model=KM2M_Combo-L

[GiddyupGilbert]

Advanced memory controller supports PC2100 DDR266 technology up to 2gig ,so that would mean you could add 2x1024

from this site !
http://www.msicomputer.com/product/detail_spec/product_detail.asp?model=KM2M_Combo-L

Caper,
Was thinking this would be the route to go. Thanks for your quick response.
Giddyup

[X-Matt]

"Theoretically DDR-SDRAM provides double the bandwidth of normal SDRAM. At 100 MHz memory clock it's able to supply a data bandwidth of 1600 MB/s, at 133 MHz it goes up to 2100 MB/s. That is why 'Team DDR' decided to call the specs of those two DDR-memory types 'PC1600' and 'PC2100'. However, I have to disappoint you, if you should think that DDR-SDRAM is simply twice as fast as SDRAM at single data rate. The basic reason is rather simple. While DDR-SDRAM is indeed able to provide double the peak bandwidth of normal SDRAM, it has still the same (CL2 DDR-SDRAM) or even a slightly worse latency (CL 2.5 DDR-SDRAM) than its older sibling. The result is that in worst-case situations DDR-SDRAM can be as slow or even slightly slower than normal SDRAM. At the same time DDR-SDRAM can easily outperform single data rate SDRAM under ideal conditions. In average, systems with DDR-SDRAM are most certainly faster than systems with normal SDRAM, but the gain depends on the application and can hardly ever reach more than 20%."

[GiddyupGilbert]

"Theoretically DDR-SDRAM provides double the bandwidth of normal SDRAM. At 100 MHz memory clock it's able to supply a data bandwidth of 1600 MB/s, at 133 MHz it goes up to 2100 MB/s. That is why 'Team DDR' decided to call the specs of those two DDR-memory types 'PC1600' and 'PC2100'. However, I have to disappoint you, if you should think that DDR-SDRAM is simply twice as fast as SDRAM at single data rate. The basic reason is rather simple. While DDR-SDRAM is indeed able to provide double the peak bandwidth of normal SDRAM, it has still the same (CL2 DDR-SDRAM) or even a slightly worse latency (CL 2.5 DDR-SDRAM) than its older sibling. The result is that in worst-case situations DDR-SDRAM can be as slow or even slightly slower than normal SDRAM. At the same time DDR-SDRAM can easily outperform single data rate SDRAM under ideal conditions. In average, systems with DDR-SDRAM are most certainly faster than systems with normal SDRAM, but the gain depends on the application and can hardly ever reach more than 20%."

Great info; does give me a better picture of the dif. I will go with the DDR even if only a 20% gain. I will be going from 512SD to 2 gig DDR. I figure just the volume along will have my sys operating more efficiently. Thanks for your input, a definite input of good info.
Giddyup