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With the Core i7 platform, memory speeds of up to 1600MHz are officially supported, but kits are sold with speeds of up to 2133MHz and beyond.

Are the caveats/drawbacks of using faster-than-rated memory the same as overclocking, or is there a specific technical reason why the faster memory is unsupported or could cause problems?

Edit: I am referring to running the memory at the advertised module speed (2133MHz, for example) on a platform that doesn't "officially" support it. I know that the module would downclock by default and run at the normal supported bus speed without any intervention.

In servers, I realize that keeping the bandwidth in check is a critical issue, especially with dozens of DIMMs and hundreds of GBs flowing around. Perhaps these are related?

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up vote 1 down vote accepted

The 1600 MHz limit is generally imposed by the CPU, not the motherboard.1 Most motherboards support higher clocks.

If your motherboard supports clocks higher than 1600 MHz, you'll be able to overclock the CPU's memory bus. This usually goes well. I'm using 1866 MHz RAM myself with no instability whatsever.

If your motherboard doesn't support clocks higher than 1600 MHz, any memory you install will simply not be able to run at higher speeds.

1 Traditionally, the opposite was true, as the memory controller was part of the northbridge (motherboard). However, Core i7 processors have the memory controller inside the CPU.

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So this would essentially be equivalent to overclocking, there's nothing special about it? – Bigbio2002 Apr 3 '13 at 16:33
Nothing special, no. – Dennis Apr 3 '13 at 16:37

The memory will run at the rate specified by the motherboard. Memory kits are sold at higher values to enable overclocking of the memory. Running this memory at a lower rate causes no drawbacks.

It's like running your Ferrari at normal highway speeds it can go a lot faster but its not harming the car.

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even though the i7 cpu may only support up-to 1600mhz other components on your mobo such as your graphics card if it uses your memory will take advantage of the full 2133mhz.. the only downside of overclocked memory is that in a laptop they tend to get a bit hotter and have more errors then standard clocked stuff..

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Memory doesn't run at different rates for different components. – Brad Patton Apr 3 '13 at 16:20
This answer is complete nonsense. – Ramhound Apr 3 '13 at 16:27
In addition to what Brad Patton said, a dedicated graphics card doesn't use system memory. – Dennis Apr 3 '13 at 16:31
my friend you are wrong. I have a dedicated graphics card with 1gb dedicated and it uses almost 2gbs of my 8gb total making my effective memory only 6GB. Its like swap on your computer, when you run out of memory it simply draws from the swap.. for your gpu, hardrive swap would be far to slow. So when it runs out of its dedicated memory it draws from the system memory that it has reserved.... – dashboard Apr 3 '13 at 16:37
What card is it, exactly? Certain cards have a feature called "Turbo Memory" or similar that uses a portion of your system RAM for itself, but it's only on specific cards. It's not standard behavior. – Bigbio2002 Apr 4 '13 at 18:13

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