# 4-4-4-12 vs. 5-5-5-15 RAM



## Toucan Sam (Jul 5, 2008)

As it says, what's the difference between 4-4-4-12 RAM and 5-5-5-15 RAM? Is that a significant factor in buying ram other than compatibility?


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## mattlock (Dec 28, 2005)

The numbers represent the RAM timing settings. Generally, the tighter the timing (samller numbers) the faster the RAM. For example, if you were to compare Corsair XMS2 PC6400 @ 4-4-4-12 with Corsair XMS2 PC6400 @ 5-5-5-15, the 4-4-4-12 RAM would typically be faster.


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## Toucan Sam (Jul 5, 2008)

Oh ok. is there any overclocking required to get the 4-4-4-12 or can you just buy it like that?


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## HawMan (May 12, 2006)

You buy the RAM as 4-4-4-12, however i personally have used 4-4-4-12 RAM and its shown as 5-5-5-15 in the BIOS, But it can Easily be changed with a few settings in the BIOS.


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## Toucan Sam (Jul 5, 2008)

HawMan said:


> You buy the RAM as 4-4-4-12


So all RAM comes as 4-4-4-12? or just some?


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## mattlock (Dec 28, 2005)

If it's advertised as 4-4-4-12, that's speed at the manufacturer has certified the RAM to run. So if it won't run at that speed you would have a valid reason to RMA the RAM and have it replaced. RAM that is advertised as 5-5-5-15 is only certified to run at 5-5-5-15. Although it my be capable of running at 4-4-4-12 stable, the manufacturer is only guaranteeing that it will run at 5-5-5-15.

As Liam stated, 4-4-4-12 may default to 5-5-5-15 for compatibility reasons, but the timings are easily adjusted via the Bios on most aftermarket motherboards. The vast majority of OEM motherboards (Dell, HP, etc) and many micro atx motherboards are very limited when it comes to tweak options in the Bios.


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## Toucan Sam (Jul 5, 2008)

oh ok. thanks for explaining all that.


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