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Old 12-31-2006, 04:39 AM   #1 (permalink)
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hi everyone happy new year. take a look at this:

ok, this is what i've got now.
i lowered the clock speed a little and finally figured out how to change my ram to its rated timings.
now, my question is, when i start raising the cpu clock again, do i need to drop my ram speed to 667 mhz so i don't overclock it too far?
next, do you think i will be able to lower the command rate to 1t and retain stability (no problem with these settings so far)?
next, notice cpuz on the fsb/dram area says cpu/6.
does this mean that since my ht multiplier is 4, that my divider is 4/6?
if so, then the only way to get my rig on a 1/1 divider is to lower the multiplier to 10, and raise the ht multiplier to 5....? blink blink blink...i haven't tried that yet, but i know i will have to drop to at least 667mhz to be able to stabilize the ram. what do you think?
any suggestions would be appreciated!

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Old 12-31-2006, 05:56 AM   #2 (permalink)
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Uhm. The way I understand what CPU-Z is reporting, CPU/6 means your memory runs at FSB * 11/6. Try it: 234.4Mhz * 11/6 = 429.6Mhz. So it's a 6:11 FSB:RAM setting, or a 11/6 memory multiplier, which is almost 2:1 (you call it a divider, but since it makes the RAM run faster than the FSB, I think 'multiplier' is more appropriate).

AMD has a strange way to handle memory clock; I guess it's because of the integrated memory controller.

Correct me if I'm wrong, but you're overclocking by changing the FSB, not the CPU multiplier (default is 11x). In order to make the RAM run 1:1, you gotta change the CPU/6 setting. What are the possible settings in the BIOS? If I'm understanding this thing correctly, the multiplier must end up as CPU/11 (or CPU/10 if you change the multiplier to 10x).
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Old 12-31-2006, 03:37 PM   #3 (permalink)
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okay that makes sense i was just thinking about it on my way home today. what the "cpu" in the cpu/6 means the actual clock speed, divided by 6. gotcha.
you are right, i overclock by changing cpu clock.
okay in bios:
i can change the speed of the ddr. 800mhz gives me the cpu/6.
667 mhz is cpu/7 533 is cpu/8 400is cpu/9.
my cpu multiplier i can change down to whatever, but highest is 11.
so to run 1:1 i would have to lower my cpu multiplier to 9 and my ram speed to ddr2 400.
i don't know if my ram will post at that speed, though.
and also, i don't know that my mobo will like a cpu clock of 280-300+ to achieve the overclock i want.
also, since the "multiplier" is almost 2:1 faster than my fsb it seems that i am wasting a lot of ram speed?
i'll try it though and get back to you.
oh, and thanks for the helpful answer. i was hoping i wouldn't get some jack@$$ reply like, "get a conroe and don't worry about it".
thanks. lemme know what you think of my theory above.
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Old 12-31-2006, 07:05 PM   #4 (permalink)
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Your theory makes a lot of sense. If those are the BIOS choices, then the only solution I see is going for a 9x CPU multiplier and setting the RAM multiplier/divider to CPU/9 (DDR2-400). Try posting at that speed. If it won't, then you'll have to overclock the FSB (thus CPU and RAM) from the start.

However, can I ask why you want the memory to run 1:1? Sure, it's supposed to provide the best performance, but as far as I know it doesn't make that much of a difference. See below for an attempt at an explanation.

A better course of action would be to think of a target CPU overclock frequency and then figure out what RAM multiplier will bring it closer to 1:1 without sacrificing too much RAM clock.

Ramble ahead:
Having the RAM on a multiplier different than 1:1 doesn't "waste" speed. Imagine your FSB is at 266Mhz and you have DDR2-800 RAM (400Mhz real) running at 1:1; then the ram is downclocking to 266Mhz. Now it's wasting a lot of its potential. By running it with a 2:3 FSB:RAM setting (a 1.5x multiplier, or 3.0 as some BIOS report it, considering DDR), you make it run at 266 x 1.5 = 400Mhz, its design speed. That's its internal speed. The multiplier means that the CPU accesses the RAM (through the FSB) at only 266Mhz (the FSB frequency). However, since the RAM usually takes several clocks (starting with your RAM latencies) to do any operation, it doesn't really matter. The performance loss is not perceptible.

Hope that made sense.
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Old 12-31-2006, 08:52 PM   #5 (permalink)
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okay the reason is that i thought it would be more effcient, as the cpu is not bottlenecking the ram.
also i have read that a 1:1 is more easily stabilized.
i can get it to 300mhz cpu x 9 gives me my 2.7, so i have no loss of clock speed, it's actually higher than i am able to typically get it with a 10 or 11 multi. (my board will NOT boot faster than 300, no matter cpu voltage or multiplier. i wonder if i should increase the chipset voltage???)
but, this means that my ram is also running at 300. i have it set at ddr2-400. now, i can increase the ram speed to 533 or 667, and keep everything else the same.
therefore my ram would be running way closer or above it's rated speed.
now, my question is...
is it better for me to reach the 2.7ghz using a 300x9 formula...or better to use 246x11?
meaning is it better to have a higher frequency or a higher multiplier?
another thing...
i can run my ram in 1t at these speeds. that giving me any benefits?
lol my target frequency is 3.0 ghz but i dont think i'll get it with this one.
thanks for the help
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Old 12-31-2006, 10:19 PM   #6 (permalink)
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Let's say 1:1 is more "natural", since the RAM is accessed by the FSB at regular and determined intervals. When they're out of synch (through a divider/multiplier), sometimes the FSB has to wait for the RAM to become ready, so you lose a couple cycles. Performance-wise, the difference may not be noticeable. As for stability, it may true that 1:1 is a little better, but I haven't seen any concrete evidence to support such claim. Nevertheless, I'd aim for 1:1, if possible, just to be sure .

Quote:
Originally posted by nagasama
now, my question is...
is it better for me to reach the 2.7ghz using a 300x9 formula...or better to use 246x11?
meaning is it better to have a higher frequency or a higher multiplier?
another thing...
i can run my ram in 1t at these speeds. that giving me any benefits?
lol my target frequency is 3.0 ghz but i dont think i'll get it with this one. thanks for the help
300x9 is definitely better! Why? Because a FSB at 300Mhz will provide a larger bandwidth between CPU and RAM! As far as I know, the CPU clock multiplier by itself has no impact whatsoever on performance. So between two equal clock speeds, always go with the larger FSB frequency.

RAM should run at 1T command rate, if possible. You usually don't need 2T unless you have stability issues, ie: if your RAM banks are fully populated. The memory will be slower at 2T, naturally; some say around 5% slower, but it's hard to gauge.
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