DDR RAM

[SEALTEAMTHREE]

Are DDR ram and mobo's worth the pricetag? This guy in my squad told me that his computer can beat mine in clockspeed because his RAM runs 100 MHz faster than mine. Is it true that a DDR system will increase system performance by 50% across the board, or is this guy pulling my chain?

[Roy]

Welcome aboard!

Stick around and sniff out more info about DDR. Your buddy seems to want bragging rights, but for many of us, Systems Optimization and Overclocking is not a contest. It's a hobby for me, and very educational.

I know this much for sure. RAM transaction speed is not the end-all for performance, any more than being able to red line an engine at 7500 necessarily makes a lawnmower go faster. And performance benchmarks are not about what the user experiences in real world applications.

There's a lot to be said for a fast, powerful system that doesn't cost a month's pay!

[batmeat]

Your friend is pulling your chain. In theory it works because DDR ram can be accessed on the up and down cycle where as SDRAM can only be accessed on the up or down. I can't remember which.

[bwkaz]

DDR RAM runs at the exact same clock speed as normal SDRAM. But, as batmeat pointed out, the DDR can transfer data on both the rising and falling edges of the clock signal, while SDRAM can transfer on _either_ the rising _or_ the falling edge (I want to say it's the rising edge, but I'd have to look at datasheets to be sure). But not both edges.

So the DDR memory subsystem itself runs faster, but the rest of the computer is still at whatever frequency it ran at before.

Put another way, the memory throughput is theoretically doubled (theoretically because there are practical limits on the speed, too), but the rest of the system is still the same.

Bryan