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I'm confused with relation between frequency and timing information when buying DDR3 RAM modules. I have OCZ DDR3 modules which should have 1600MHz frequency and CAS 7-7-7-20. If I use these modules and do not specify any configuration in BIOS they really have CAS 7-7-7-20 but frequency is set to default 1066 (system with Intel i7 920). If I manually change frequency to 1600 the CAS is 9-9-9-24. If I manually change both frequency and timing information to 1600 with 7-7-7-20 my system will not boot because of overclocking failure. I do not want to overclock the system. I just thought that memory should run on 1600MHz with CAS 7-7-7-20.

So are these values related or they only shows best values which memory modules can achive but these values don't have to be achived together? If these values are not related which one is more important?


Motherboard is Asus P6T Deluxe V2. I see that description shows that 1600MHz modules are supported only with overclocking.

Question about importance of values is already obsolete because by playing with different settings in BIOS I found that my motherboard uses only 4 of 6 RAM modules if frequency is set to 1600MHz.

share|improve this question
What motherboard do you have? – William Hilsum Feb 6 '11 at 1:27
also check – nik Feb 6 '11 at 4:02
Making them run at 1600MHz would be overclocking them – Sathya Feb 6 '11 at 8:46
@Sathya: Can you explain this? – Ladislav Mrnka Feb 6 '11 at 9:29

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