Question about RAM types

[Holy Cheese]

While pondering the possibility of putting together a new pc, I've been looking at various components but am confused about RAM modules.

I keep coming across terms like CL7, CL8 or CL9 and then the various clock settings.

Can somebody tell me in laymans terms what is better? Is CL9 better than CL8, for example?

Thanks in advance

Jack

[Atomic_Sheep]

The smaller the latency for a given clock speed the faster the memory. Lets take CL9 vs CL8 for example. If both are 1600mhz, then the CL8 will be quicker as the latency on a CL8 might be 8-8-8-22 vs CL9's 9-9-9-24 (4:30am so the latencies I'm making up on the spot to illustrate the point). So for a given clock speed the amount of times that a process will be thrown back and forwards on a CL8 memory stick will be 8 times while on a CL9 will be 9 times (everything is very approximate here and probably full of errors but the point should be correct). Now take two memory sticks with 9-9-9-24 latency for example with different clock speeds of lets say 1600mhz and 2000 mhz. Now the process gets thrown back and forth the same number of times between regardless of the memory type but the 2000mhz will simply do the whole process/operation faster. So really think of the clock speed as the width of a water pipe... the thicker the pipe, the more water flows through... and think of the latency as the number of kinks from point A to point B with less obviously being better as it's the most direct route from point A to point B. NOW... realistically 2000mhz and 1800mhz and even 1600mhz (which I have atm and to some extent) is just there for bragging rights only. My memory is only running at 1066mhz at the moment because I haven't started overclocking my computer yet although it's capable of running up to 1600mhz. With the same memory stick... if you reduce the clock speed 1600->1066 like mine is, you can reduce the latency... can't remember what mine is set to... I think it's 7-7-7-twenty something. So as you can see... if you increase clock speed, you need to increase latency but the result is that your memory will work at the exact same speed. The whole point of this is to to make it run at the speed of the processor, but the hose you purchased remains the same (I know a hose here doesn't make sense in the sense that you can increase the number of kinks/s bends but you can't increase it's thickness so imagine a hose that automatically becomes thicker the more kinks you add and that being the properties of the hose that still rate it at 1Gb regardless of what you do with the hose - if this doesn't make sense then ingore this last big in the brackets I think it should make sense without this waffle).

NOW... the reason why 2000mhz costs so much is because it's basically overclocked slower memory. What this means is... take a 1600mhz 9-9-9-24 and bump up voltage or something like that (not sure how to overclock memory) with this increase of voltage, you can now increase the frequency/clock speed and maintain the same level of latency. Doing so increases memory temps, reduces their life etc etc... wont go into that.

Finally... all that has been happening with memory for the past... many years... is theyve been bumping up clock speeds and making it seem that the memory is getting quicker whereas in reality the latency has also been increasing which means that this new memory is pretty much the same memory you saw when DDR1 was out with 400mhz clock speed but a latency of 2-2-2-5 or whatever it was back then. Sure there are other differences between DDR1, DDR2 and DDR3 but really... the performance hasn't increased by all that much. You may have noticed that what has been increasing over time is the requirement to have more memory... i.e. everyone now recommends to have at least 2GB... enver used to be like that. Now if memory was increasing in speed... then you would be using the good old 512mb or whatever and not needing to worry about getting new fancy memory. Taking what I'm saying into considering means that to speed up the computer you simply need to install more memory. Don't worry about spending big bux on super memory with crazy 2000mhz... coz a.) your computer will not be able to utilise it.

Now sure... given a choice of 1600 9-9-9-24 (CL9) vs 1600 8-8-8-22 (CL8) or whatever the latency is for CL8 maybe its 8-8-8-24, sure the latter will be quicker but if you can SEE the difference then hell... you'll be the first. I think the performance gain is something in the order of 5% or something. If you can find CL8 memory for a 5% price premium... go for it... if not then ask yourself if CL8 is worth it? Or even CL7 but that stuff is just stupidly expensive. Basically don't worry about it... and get the cheapest memory... you won't be able to tell the difference.

EDIT: Go with the fastest clock speed memory that your motherboard can support. No point getting 2000mhz memory if your motherboard maxes out at 2000. Mine maxes out at 1600 so I went for that one. Besides it was the cheapest memory that was out there (almost). Do I think my comp is slow? Hell no.

[Holy Cheese]

Thanks Atomic Sheep, wish I was as lucid at 4:30 am 

That made it nice and clear for me, I can strike this off the list and go check up on things like mobos now.

Thanks for the help.

Jack