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danger55

Still can't figure out mem ratio

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I've read through the o/c guide and a heap of other info but still don't quite get it.

ATM I'm clocked at 2.45Ghz (245*[email protected]) and have set the mem to DDR800. So the memroy is overclocked to about 983Mhz as shown in bios. CPU-Z is showing memory freq as 491.6Mhz and FSB:DRAM as CPU/5. Now if I want to get a 1:1 ratio, where do I go from here?

I thought I need to drop the mem freq in bios to the same 245Mhz to reach 1:1 but the options only include DDR800, 667, 533.....I just can't seem to see how to effectively reach a 1:1 ratio within these settings.

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I've read through the o/c guide and a heap of other info but still don't quite get it.

ATM I'm clocked at 2.45Ghz (245*[email protected]) and have set the mem to DDR800. So the memroy is overclocked to about 983Mhz as shown in bios. CPU-Z is showing memory freq as 491.6Mhz and FSB:DRAM as CPU/5. Now if I want to get a 1:1 ratio, where do I go from here?

I thought I need to drop the mem freq in bios to the same 245Mhz to reach 1:1 but the options only include DDR800, 667, 533.....I just can't seem to see how to effectively reach a 1:1 ratio within these settings.

 

remember that the memory is DDR2...so DDR2-800 is really just 400Mhz x2 (ie: double data rate)

 

the FSB on the AM2 cpu is still only 200, or DDR 400 (200Mhz x2).

 

by default the memory controller is set to run 2:1

 

so if you are running 800Mhz DDR (its DDR2, but the important bit is DDR which means double-data-rate), your cpu's fsb is still only 400Mhz (200FSB = 400Mhz, or 200x2 for double data rate)

 

If you drop the memory controller to 1:1, you are forcing the RAM to run at 200Mhz, just like the cpu's FSB (ie 200Mhz x2, or 400Mhz double data rate)

 

so, the memory is 800Mhz DDR, the cpu is 400Mhz DDR, hence 2:1 ratio (the '2' on the DDR2 should not mean anything to you other than second-gen DDR RAM)

 

when you do 245FSB, you are running 245Mhz x2 (double data rate), or DDR490

 

since the memory controller is set to default @ 2:1 (or forced to 2:1 by using the DDR800 divider), then you have to double both sides

 

so on the 2:1, your 2 would be 490Mhz, and your 1 would be 245Mhz

 

when you double it, you come up with 980Mhz on the memory (double data rate remember), and 490Mhz on the FSB (double data rate remember yet again)

 

make sense? ;)

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Makes sense- thanks for the excellent explanation.

So I guess my question now relates to whether I should stick with 2:1 or try and get it to 1:1. From the O/C guide, I thought 1:1 was most desirable.

Is it still ok to keep my memory clocked to 980Mhz? Or should I drop it down to about 400 or 533 to get closer to a 1:1 ratio?

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Makes sense- thanks for the excellent explanation.

So I guess my question now relates to whether I should stick with 2:1 or try and get it to 1:1. From the O/C guide, I thought 1:1 was most desirable.

Is it still ok to keep my memory clocked to 980Mhz? Or should I drop it down to about 400 or 533 to get closer to a 1:1 ratio?

 

1:1 is most desirable on a system that is limited to DDR1

 

2:1 is most desirable with DDR2 since 2 is greater than one...

 

ie: 2x memory bandwidth is better than only 1x memory bandwidth....correct?

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ie: 2x memory bandwidth is better than only 1x memory bandwidth....correct?

Hell your the teacher why you asking us this DDR2 stuff is new to us

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1:1 is most desirable on a system that is limited to DDR1

 

2:1 is most desirable with DDR2 since 2 is greater than one...

 

ie: 2x memory bandwidth is better than only 1x memory bandwidth....correct?

 

All clear- thanks for the help...

time to start cranking things up a little (and I guess that can only mean plenty more questions)

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