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Really confused by DDR2

post #1 of 4
Thread Starter 
Ok, I am looking at some Intel builds that would use DDR2 RAM, and I am really confused! It will say stuff like, DDR2 800, or DDR2 667 etc, but I thought RAM was 2x the FSB, so does DDR2 just use different multipliers? Also, it seams that most motherboards support DDR2 667, but some support DDR2 800. Is there a big difference between DDR2 667 and DDR2 800?
post #2 of 4
Quote:
Originally Posted by SoaDMTGguy
Ok, I am looking at some Intel builds that would use DDR2 RAM, and I am really confused! It will say stuff like, DDR2 800, or DDR2 667 etc, but I thought RAM was 2x the FSB, so does DDR2 just use different multipliers? Also, it seams that most motherboards support DDR2 667, but some support DDR2 800. Is there a big difference between DDR2 667 and DDR2 800?
DDR is triggered by the rise AND fall of the clock sinusoid, so it actually executes 2 instructions per clock cycle. It doesn't actually operate at double the speed, but it performs as fast as single data rate ram would if the speed were doubled. DDR2 is similiar,but performs 4 instructions per clock cycle. While DDR2 is faster, it also can't have as tight of timings.
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Intel 80 gb SSD, Raptor 150 Windows 7 Home Premium 24" Samsung LCD Saitek Eclipse 
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post #3 of 4
Thread Starter 
Quote:
Originally Posted by sccr64472
DDR is triggered by the rise AND fall of the clock sinusoid, so it actually executes 2 instructions per clock cycle. It doesn't actually operate at double the speed, but it performs as fast as single data rate ram would if the speed were doubled. DDR2 is similiar,but performs 4 instructions per clock cycle. While DDR2 is faster, it also can't have as tight of timings.
I had noticed that, although people have told me that timings don’t matter as much on Intel chips. Is there a in depth guide to DDR2 that you could link me to
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74Gb Raptor + 750Gb Seagate eSata XP Pro Samsung 226BW 22" LCD Logitech 
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