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Old 04-13-2006, 01:45 PM   #1 (permalink)
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Default FSB compared to RAM speed

I just have a simple question. How come FrontSideBus is always faster than the RAM. For example you have a 2000Mhz bus with works with RAM going as fast as 800Mhz. Why the big differences.
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Old 04-13-2006, 01:50 PM   #2 (permalink)
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2GHZ FSB is from AMD and is NOT the actual FSB. Being that the memory controller is on the chip, the FSB will run as fast as memory up to 2GHZ on the particular chip that says it. So if you get DDR400 then your FSB will run at 400mhz. If you use DDR333 then your fsb is 333mhz.
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Old 04-13-2006, 03:36 PM   #3 (permalink)
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Shawn

I'm relatively new to the overclocking scene and still getting the intracacies down. What about a divider running at a 5:4 ratio? If you have a FSB running @ 200MHz dosen't your memory run at 180MHz? If that's the case, does your system bottleneck in the RAM?
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Old 04-13-2006, 03:47 PM   #4 (permalink)
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I believe so which is why you always want to push for a 1:1 ratio.

Please open another thread in the proper forum if you have a question so that we dont hijack other peoples topics.
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Old 04-17-2006, 01:13 PM   #5 (permalink)
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Quote:
Originally posted by SHAWN
2GHZ FSB is from AMD and is NOT the actual FSB. Being that the memory controller is on the chip, the FSB will run as fast as memory up to 2GHZ on the particular chip that says it. So if you get DDR400 then your FSB will run at 400mhz. If you use DDR333 then your fsb is 333mhz.
Shawn wouldn't your FSB speed always stay 200 mhz which is the real speed of current AMD cpu's? Upping or lowering the FSB would change the CPU speed. Since the CPU speed = FSB x The multiplier.
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Old 04-18-2006, 05:04 AM   #6 (permalink)
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i just have simple question
i if my ram speed is 400MHz, then will my FSB run on 400MHz even if it says 800Mhz???
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Old 04-18-2006, 01:15 PM   #7 (permalink)
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Well this may be a bit confusing but your FSB and RAM are both running at an actual speed of 200 mhz. Intels CPU's are quad pumped so it has an effective FSB speed of 800 mhz. DDR RAM sends two data transfers per clock cycle which gives it an effective speed of 400 mhz.
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