Worth running DDR2-667Mhz memory at 800MHz (7-7-7-20 timings)?

[kanako0727]

I have some Patriot memory that's rated to run at 667MHz at 5-5-5-15 at 1.8V. I've been running a blend test in Prime95 for close to six hours now with the RAM at 800MHz at 7-7-7-20 at 2.1V. Is it worth increasing the memory to this speed if I have to loosen the timings so much?

 

[fffblackmage]

Well, you're looking at increasing the latency from 7.5ns to 8.75ns. Along with increased voltage, that's the price you have to pay for the increased bandwidth.

I don't think it's worth it from the increase of voltage alone. With DDR2-666, you generally have plenty of bandwidth anyways.

I would leave it at 666MHz and continue using the normal voltage.

 

[tweakboy]

I agree totally. Your not going to see a speed increase from 667 up to 800 with those timings,, if anything things will be slower. Thats enough bandwidth if you dont do intensive stuff like CAD or Video Rendering or DAW

 

[tweakboy]

What is this 7.5ns lol your talking about blackimage my amigo.

Ram latency on avg peoples recent PC's are avg 70ns ... not 7 buddy. If you have one in the fifties like me it helps a lot very snappy

 

[fffblackmage]

What is this 7.5ns lol your talking about blackimage my amigo.

Ram latency on avg peoples recent PC's are avg 70ns ... not 7 buddy. If you have one in the fifties like me it helps a lot very snappy

Take the inverse of the frequency to get time, multiply with the # of clock cycle delay, and presto, you have latency in time.
1 / (666,000,000 Hz) = 1.5e-9 s = 1.5 ns
1.5 ns * CAS 5 = 7.5 ns

It's actually more complicated than that... but I think it's a good enough estimation to compare timings at different frequencies. This is an excellent read if you want to know more, especially why the latency isn't always going to be something like 7.5ns: Everything You Always Wanted to Know About SDRAM (Memory): But Were Afraid to Ask

 

[tweakboy]

Blackimage I like you I dont want to argue with you, but maybe your thinking of something else,,, there is no RAM in this world that is 7ns

Just use Everest program and do benchmark memory latency, this is what you get.