Your CPU runs a bus speed of 200Mhz, the RAM is 400Mhz.
2 x 200 = 400, hence the 1:2 at 1:1 your RAM would only run at 200Mhz although you might be able to get away with lower CAS timings. I'd stick with 1:2, my Asrock board wouldn't let me do 1:1 with such a low FSB.
(to avoid confusion, the chip uses quad data rate, so Intel calls it a 800 FSB, but it's really 200Mhz x 4, newer chips on your platform are 333 x 4 or 1333, you can overclock many to 400Mhz x 4 (a.k.a. 1600FSB) and run 1:1 with DDR2-800 (400Mhz) - requires decent heatsink to do this btw)
Change your System Memory Multiplier from AUTO to Manual. Then select the 2.00B multiplier. If your FSB is 200 MHz., the Memory Frequency will show 400 MHz. This will give you a 1:1 ratio (DDR2 memory, remember?).
Then, if you decide to try to overclock, the memory frequency will always be twice the FSB.
bclk x 4 = FSB
bclk x multiplier = cpu speed
bclk x 2 = memory speed for DDR2
So the clock is set for 200MHz (continuing the idea from before) and memory set to 1:2 you'll have:
200 x 4 = 800MHz FSB
200 x 12.5 = 2500MHz cpu
200 x 2 = 400MHz memory (1:2 setting, or 1:1 effective frequency ratio)
Some boards with DDR2 will show the lowest setting as 1:2. They are showing the "bclk : effective memory speed", so 200:400, or 1:2.
Other boards with DDR2 will show the lowest setting as 1:1. It is really saying "200MHz clock : 200MHz memory" but double this for your effective frequency.
On your Gigabyte G41-ES2L the lowest setting will be 1:2. This is shown as bclk : effective memory (clockx2).
On a J&W G31-MKII the lowest setting is 1:1. This is shown as bclk : memory clock (not the DDR2 rate).
Both of those settings on each board results in the memory working at the same speed. It's often the case when someone is asked to set their board to 1:2 or 1:1 they are being asked to set their board to the lowest settings. One board's setting of 1:2 is another board's setting of 1:1.
bclk x 4 = FSB - no
bclk x multiplier = cpu speed - yes
bclk x 2 = memory speed for DDR2 - yes
bclock is, I am assuming "base clock". FSB is a thing - the path into and out of the CPU. Frequency (more commonly - and less accurately - known as "speed") is one of its characteristics.
If we are agreeing on definitions,
bclk = FSB frequency = 200 MHz for the E5200.
FSB clock = FSB frequency X 4 ("quad pumped bus transfers 4 chunks of data each FSB cycle) = 800 MHz.
What is known as the "1:1" ratio (and what CPUZ would report) means that the FSB and the memory are working synchronously (in step together). For this to happen,
Memory clock = FSB frequency X 2 (memory transfers 2 chunks of data each bus cycle - DDR2 memory) = 400 MHz.
Yes, that's what I get for attempting to be brief. Apologies!
No, I didn't mean that a frequency multiplied by a number equaled a physical part of the computer. It should have read "FSB speed" and I was implying the general term. All three were intended for comparison.
Considering we are discussing ratios, frequencies and clocks in this thread, an omission like that might have been inferred, but if not, I hope I've corrected it.
Had I posted -
bclk x multiplier = cpu
leaving speed off the end, I would have thought most people reading that would have inferred I was meaning the cpu speed, not the cpu itself.
I don't think anyone can creat a physical cpu by taking a frequency and then multiplying it by a number. Otherwise we could all tune the radio to the frequency of our choise, pick a number at randomn and have cpu's appear in front of our eyes. So, no, I didn't mean the frequency mulitplied by a number did, in fact, become the front-side bus.
Yes, it's a problem of vocabulary and definitions, all right. And it's complicated by different motherboard makers and BIOS writers using slightly different terminology. And then it is aggravated by our casual usage.
Indeed. I can imagine somone instructed to set their memory to 1:1, but when they delve into the BIOS and find settings of 2.6, or 123MHz, or even "1:2" as the lowest option available and they still can't find the mythical and fable beast of "1:1" on the screen as an option, they reply in the moden day "WTF?".
As always, an understanding of the underlying principles will enable anyone to go into their BIOS and change what needs to be changed, knowing full well the impact and outcome on the relationships between components, rather than doing it by rote, perhaps oblivious to what those changes mean.
Anyway, apart from odd typographical error, I'll attempt to use the little amount of jargon I know correctly, while at the same time not committing future forum faux pas.