10-27-2009, 02:54 AM
(This post was last modified: 10-27-2009, 02:54 AM by Shadow Lady.)
Basically you cant do it manually, usual mobos only overclock the ram when you overclock the cpu so for example you have a CPU running at 200mhz FSB with a 800MHz DDR2 ram, and then if you overclock the CPU to 250MHz FSB the RAM would be running at 1000MHz.
What you can usually do for RAM is change the timings and change the FSB:RAM ratio, the FSB is the bus speed and what you overclock your CPU with, so you can choose speeds like 667MHz 800MHz 1066MHz etc those are running at a ratio from the CPU. So for example if you overclock that 800MHz to 1000MHz because of the CPU overclock it might not be stable already or go any higher so lowering that Ratio would let you, like you choose 667MHz and then when overclocked to the 250MHz FSB the RAM would be running at 833MHz which is barely overclocking the ram at all but might tbe stable and let you continue overclocking the CPU, and also you could choose a higher ratio than your ram is rated to work at and it may actually work effectively "overclocking" it.
You can also have a mobo that lets you lock the memory clock so it runs at the same speed always, or a mobo that doesnt let you change more than the timings at all but at least I havent seen any that lets you overclock the ram independently.
Core i5 3570k -- Geforce GTX 670 -- Windows 7 x64
As above, its all tied with FSB. You can change the FSB:RAM ratio to effectively overclock memory without changing your FSB. However, do note that overclocking RAM by itself won't give any noticeable increase in performance. You'll see a marked increase in bandwidth using synthetic benchmarks, but in real world performance, you won't notice it at all.
Also, the FSB:RAM ratio is has many names on different motherboard BIOSes. It's called 'Memory Multiplier' on Gigabyte boards, while it's also known as memory divider, FSB:RAM divider on some other boards as well. Not sure what it is on Nvidia boards, but look for some of those names.
Booger: It really depends. If you have a processor that works a lot faster than your ram, then a decent overclock to ram can actually have a fairly decent and noticable effect.
Though if you're already sitting at the fastest ram your mobo supports, chances are you don't have a CPU that would exceed that amount of bandwidth.
You can also try messing with your ram timings... but you're even less likely to notice a difference with that and much more likely to cause stability problems.
As long as you can keep at least a synchronous FSB:RAM ratio of 1:1, any other increases in RAM speed will have minimal impact on performance with C2D CPUs (not too sure the effect on i5/i7 with the onboard memory controller). Of course, this excludes applications that are memory-intensive, including many professional programs and also calculations such as SuperPi. But in general desktop usage and gaming, the difference between 1066Mhz RAM and 800Mhz RAM is unnoticeable.
thanks all,so i wont notice any speed ups ok
Some boards allow you to just overclock the RAM, albiet there increase in bandwidth amounts to nothing, DDR2 800MHZ is all that you need.
AMD Phenom II 940 @ 3.6GHZ, 4GB PC8500 @ 1100MHZ, 4870x2 @ Stock.
but by just overclocking the cpu,im not overclocking the ram also??
10-28-2009, 12:51 PM
(This post was last modified: 10-28-2009, 12:51 PM by boogerthe2nd.)
As long as the FSB isn't raised higher than half the RAM's rated speed (since it's Double Data Rate), you won't need to overclock the RAM at all assuming you keep a FSB:RAM ratio of 1:1.
So if you have 800Mhz RAM, then as long as your FSB is 400Mhz or lower, you'll be running the RAM at or below stock speeds.
my mems are 333Mhz as i saw at cpu-z,so maybe thats the reason i cant put the fsb higher than 295.