krazyskillz

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I have spent the best part of a week reading through online OC'ing guides and hardware reviews and I'm pretty sure I have a fairly bulletproof £1k system. All that remains are a few questions about the quoted speeds on certain components.

For example, I am looking at the MSI platinum P45 chipset motherboard which has a quoted '2008 MHz' maximum FSB OC speed. Now please correct me if I'm wrong but in order to achieve a (CPU) clock speed of 3.0GHz (a reasonable overclock for a Q6600 G0) an FSB speed of 333MHz and multiplier is required. surely running the FSB at 2008MHz would require a 1.5X multiplier! Not a common setup! Equally running at the quoted 1333MHz FSB speed would require a 2x multiplier, again I have never seen this setup on the forums!

The other speeds that have confused me are the speeds quoted on the PC2-8500C5 1066MHz Reaper HPC Edition Dual Channel DDR2 memory from OCZ. These modules are rated at 1066MHz (no OC). Does this take in to account the DDR effect of the RAM (doubling RAM speed) or is it raw RAM speed?? If so, what FSB speed and RAM speed ratios would allow me to run both memory and FSB at nearly full speed?? Or (most likely) I'm missing something fairly obvious!

Thanks for your time,

A first time system builder
 

zenmaster

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Not sure what they mean by 2008Mhz.
They are probably talking Quad Pumped so divide that by 4 and get 502Mhz.

That would seem more in reason.

If you are going to get a Q6600, you should not hit a FSB wall on any current Mobo of decent quality so don't worry about that.

It's more of a concern with the 1333FSB Quads.
 

yadge

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Yes, that's exactly it. The fsb for motherboards is quad pumped, so all it's really saying is that the maximum fsb for that motherboard is 502mhz.
 

JDocs

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To answer your question. Its kind of a yes and no. DDR2 800mhz is actually a 400mhz chip running at double bandwidth due to some clever engineering. Then the memory chips are dual channeled doubling their "speed" once again. So if your FSB is 400 you need 2 800mhz effective DDR2 (400mhz core) in dual channel to match.
 
Look at it this way, it's not really the "1333" or the "1066" that makes a difference. It's the FSB and the multiplier. The FSB is going to be 266 or 333 stock on a modern Intel CPU. All they are saying is that it will go as high as 502. People don't actually run systems at that speed day to day.

Your memory runs on a multiple of the FSB, usually *2. DDR= Double Data Rate.

If you get really lucky you can push a few CPUs all the way up to 500mhz FSB, on several newer boards. You can even get there on air cooling, boot into windows, fire up a few test utilities, and get a screenshot off before it crashes.

I'm not saying it's unimportant. Some folks really enjoy doing it, and the rest of us benefit because a very overclockable board is a stable board.
 

V3NOM

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ok dude there's quad pumped fsb or the fsb (per pipeline, theres 4 pipelines of say 333mhz which equals 333 QDR)

DDR2-1066 is almost completely unneccessary except in the overclocking of 45nm cpu's (and even then it's usually a pretty extreme OC)

hope that answers your question.