The JEDEC (
http://www.jedec.org/) standard for DDR2 memory details that the maximum speed should be 1066MHz (PC2-8500), but for some enthusiasts that just isn't fast enough. Several manufacturers produce high performance modules capable of speeds of 1100, 1200, or even 1300MHz, as long as you can provide them with 2.3V, which is also in excess of the JEDEC standard.
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*Review: Big Bruin (
http://www.bigbruin.com/2008/kingston1150_1)*
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