Memory FSB Question

edwardaune

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• Sep 20, 2004

• #1

If pc3200 is supposed to have a 400MHz FSB then when adjusting my memory latencies to 11-2-2-2 and its at a 1:1 ratio, arent I reducing the fsb because my resulting freequency is 188MHz * 2 = 376MHz?

 

JimmyG

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• Sep 20, 2004

• #2

If you are implying that your FSB is running 188, then the answer is yes. You may want to back off on the memory settings to allow an increase in your FSB.

 

David

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• Sep 20, 2004

• #3

PC3200 uses a 200MHz memory bus transmitting on the rising and falling edges of the signal, hence the effective transfer rate is 400MHz.

If your FSB is 188MHz and it is set to 1:1 ratio with the RAM then the RAM will be running at 188MHz DDR (376MHz effectively) so yes it is running below spec.

 

OP

edwardaune

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• Sep 20, 2004

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• #4

Well....Correct me if I am wrong, but when I was adjusting the latencies 11-2-2-2 showed the best results in prime. I am just curious how I change the letencies to get a 4:5 ratio. Even ata factory speeds 8-4-4-2.5 it is still 1:1.

 

David

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• Sep 20, 2004

• #5

edwardaune said:

Well....Correct me if I am wrong, but when I was adjusting the latencies 11-2-2-2 showed the best results in prime. I am just curious how I change the letencies to get a 4:5 ratio. Even ata factory speeds 8-4-4-2.5 it is still 1:1.

Click to expand...

Latencies are not ratio.

Ratio is the ratio of the FSB to the memory bus.
Latencies involve how long memory waits for during certain periods of operation.

 

OP

edwardaune

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• Sep 20, 2004

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• #6

How do I go about changing the ratio?

 

JimmyG

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• Sep 20, 2004

• #7

I don't have your mobo, but look in the bios on the advanced menu. There should be something like "CPU/Memory Frequency Ratio" Select "manual" and then you should have different frequency ratios displayed. Pick one.

 

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edwardaune

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• Sep 20, 2004

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• #8

I dont have ratios so to speak, but I do have percentages. Right now it is at 100% and the next increment up is 120% and if I pick that when it jumps up to 450MHz and the system wont boot.

 

Restorer

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• Sep 20, 2004

• #9

On that board, it's in Advanced Settings (after you hit ctrl-F1), as a percentage. By default it's set to "By SPD", but you can set it to any of a large range of percentages of your FSB. 120% is the next up from 100%, but that will give you 450, which may be too much for your RAM at 2-2-2-11. Loosen your latencies and bring it up to 120%.

 

OP

edwardaune

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• Sep 20, 2004

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• #10

Is it because my cpu is locked and I cant get to 200FSB and these are the results of that.