Overclocking to acheive 1:1 FSB:DRAM ratio ?

[AD-15]

hello,

I have a Core 2 Duo 6600 CPU, and Corsair 1066 RAM. I currently have the two running in a FSB: DRAM ratio of 1:2. I heard that the best stability is achieved when the two are running at the same speed, 1:1. To be able to keep the RAM at 1066, and have a ratio of 1:1, I need to overclock my CPU to about 2.6GHz, as opposed to just 2.4. I don't want to go into the details of overclocking just yet, I still need to read Clunk's guide. I just wanted to know would it be worth it to overclock the CPU to said clock speed to achieve a 1:1 configuration?

Thankyou!

[BUFF]

your CPU really runs at 266fsb but it's a quad pumped bus which is where the 1066 comes from.
So, to run your RAM at 1:1 CPU:RAM ratio your RAM bus should be at 266fsb but as it's dual data rate that's DDR2 533.
Tbh I would just leave it where it is until you start wanting to overclock to seriously high CPU fsb.

[aidanjt]

It's *highly* unlikely you'll get your FSB up to 533Mhz anyway (barring the use of some extreme cooling), and tbh you shouldn't want to either, other devices on your system need direct access to memory as well as the CPU, GPU and Disk drives to name but a few.

[Hottentot]

To keep your RAM at 1066 and use a 1:1 divider you would need to run your CPU at 4.8 Ghz!!. If you want a 1:1 divider it will slow your ram down to match your FSB but at least you will be able to overclock your CPU pretty easily by raising the FSB.

[AD-15]

hello,

I'm sorry, I wasn't clear at all about the 2.6 bit. Couldn't I use an FSB (ignoring quad pumping etc etc) of 533, and a multiplier of 5? I'm sorry, I'm not really sure what the mulitplier is in terms of hardware!

[AD-15]

I just noticed what happens when you try to type FSB: DRAM, and the ':' is followed by the 'D'. Edited...

[BUFF]

think that the CPU multi only goes down to x5 on C2D CPUs which would give you 3.2GHz at 533fsb (assuming that your CPU etc. can do that).
tbh imo other than for certain synthetic tests there isn't any real point in running v. high fsb.

As for CPU multi - the multi x the true CPU fsb = core speed e.g. your E6600 has a multi of 9x & a true fsb of 266.66 = 2400KHz or 2.40GHz.

[iranu]

Do any of the current 775 motherboards support a FSB of 533mhz?!! I don't think there is a performance hit with running a divider whilst the cpu is overclocked. If your PC is stable at 1:2 then it's stable, it doesn't need to be more stable.

[BUFF]

Do any of the current 775 motherboards support a FSB of 533mhz?!!

officially, no but certainly some are capable of it as long as the other hardware is too.

[aidanjt]

With beefy northbridge cooling and a decent PSU you can get 533Mhz FSB, but needless to say.. it isn't very healthy for the northbridge or CPU over prolonged periods.

[AD-15]

So, techinically, there is no problem running a multiplier of 5 with FSB of 533?

BUFF, 5x533 isn't 3200.

What exactly is the difference between running a CPU with a multiplier of 6, and an FSB of 400, and running a CPU with a multiplier of 8 and an FSB of 300? They both come to 2400....

[kidzer]

The FSB connects to other components, the multiplier is an internal 'thing' to the CPU as I understand it.

So an increased FSB will affect (sometimes detrimentally) other components aswell, byt running at a higher frequence.

[WannaPiEcE]

hello,

Overclocking to acheive 1:1 FSBRAM ratio ?

Just so the OP knows...

A 1:1 ratio has no performance gain over any other linked or unlinked ratio.

[AD-15]

So the multiplier only affects the speed of the cpu, whereas the FSB can have an effect on the performance of the whole system?

What about energy use and thermal output? Is that based on the overall final clock, or just the FSB?

[MadduckUK]

So the multiplier only affects the speed of the cpu, whereas the FSB can have an effect on the performance of the whole system?

What about energy use and thermal output? Is that based on the overall final clock, or just the FSB?

based on loooots of things, if were talking about faster processor = more voltage = more heat output, then thats a combination of the multiplier and FSB (multi x fsb = cpu clock speed)

The FSB connects to other components, the multiplier is an internal 'thing' to the CPU as I understand it.

So an increased FSB will affect (sometimes detrimentally) other components aswell, byt running at a higher frequence.

"proper" motherboards, with an nudge towards a bit of overclocking will come with the option to either fix the PCI/IDE/SATA/etc at there "default" settings, or with a divider similar to what happends with memory. allowing the FSB to go up, while the rest of the system stays close to stock. (my new one doesnt do this btw - but i can still ramp the FSB from 200 - 260)

and no, this whole fsb = memory speed is silly and pointless. just bloody get both as high as you can

[WannaPiEcE]

In personal computers, the front side bus (FSB) or system bus is the physical bi-directional bus that carries all electronic signal information between the central processing unit (CPU) and the northbridge.

In almost any situation an increase FSB will increase memory data transfer rates thus increasing the memory float bandwidth as well as overall increased data transfer from the CPU to the Northbridge.

So the multiplier only affects the speed of the cpu, whereas the FSB can have an effect on the performance of the whole system?

Yes, in a sense..

What about energy use and thermal output? Is that based on the overall final clock, or just the FSB?

Increasing the FSB will require more voltage to the Nortbridge(MCP) and FSB, so increasing the voltage will produce more heat which will require more adequate cooling.