Help understanding oc

[horaciocs]

Hi everyone :) This is my first post, finally got my acc validated :D

I am designing a C2D computer and what I have in mind is getting either a e4300 or a e6300 and taking it to around 3ghz.

However, despite having some ideas on what to do once I have the computer assembled, I still don't understand some things:

The e6300 specs say it's fsb is 1066mhz. What does that mean?

From what I have read, the fsb is set at the chipset, and it sets the frequency at which the cpu accesses the ram. Is that correct? If so, what does it mean when we say the e6300's fsb is 4x266 = 1066mhz? That's not the frequency at which the cpu accesses the ram, right? In this case at what frequency would it access the ram? 2 x 266 = 533mhz?

I am saying 2x because ddr transfers 2 bits of data per clock, am I correct?

If I have some ddr2 800mhz working along with a e6300 at 4x266, what speed will the ram work at? (at 1:1)

Despite having read some things, I am really confused with all of this. Could any of you try to explain to me how the busses work altogether? I read all about them at wikipedia but still did not quite understand what goes on inside a computer :confused:

Thank you all in advance :)


Horacio

[urbanriot]

If I have some ddr2 800mhz working along with a e6300 at 4x266, what speed will the ram work at? (at 1:1)

Horatio, this topic has also caused me a great deal of confusion as well and I've read numerous threads on it yet I'm still having issues understanding.

I found this thread, which has (kind of) helped a little:
http://forums.anandtech.com/messageview.cfm?catid=28&threadid=1990178

I purchased 1066MHz. RAM for my XBX2 / QX6700 but I don't think I'm operating it at its proper settings... I'm trying to wrap my head around it, but it's difficult to find a clear explanation and I haven't overclocked since I was a wee lad.

[K404]

Intel Quad-pump the FSB, so divide 1066 by to get 266.

DDR numbers are multiplied by 2 because its already Double Data Rate, so divide that number by 2....533, which is technically 1:1 with the FSB.

A good BIOS will provide the option of increasing the RAM speed...a C2D setup at stock can run the RAM at 400MHz (DDR800) fine.

Hope that helps a bit

Kenny

-> Welcome to XS, both of ya

[horaciocs]

nice to know im not aone, urbanriot :)

thanks for the reply, k404

When you say that I can increase ram speed at the bios do you mean making it work at 1:2 or anything else out of sync?

Now, for instance, if I use a e4300, which works at 4x200 fsb, will the ram by default work at 400mhz?

What about when people oc it to 9x400 or so, what will the quad-pumped fsb be? The DS3 can reach up to 500mhz fsb, does that mean 4x500=2000mhz?

Thanks for the help,


Horacio

[K404]

The P5B will do around 500FSB, yup. That gets Quad-pumped to 2000, and will show up as that in CPU-Z.

There are options in BIOS that are listed as RAM frequency x 2 so...if you go into BIOS and set it to run at e.g. 500x6 you can set the RAM to be at 500MHz as well...the option will be DDR1000 or DDR2-1000 or something like that.

Get to know your BIOS, it`ll all seem clear. The values in BIOS change depending on the FSB you set, so the only maths you`ll need is the ability to divide by 2 to get the actual RAM frequecy :p:


I suck at explaining things, but it aint that scary, dont worry!

[horaciocs]

nah, k404, don't worry, you're doing just fine :D

I heard from people that th e6300 is better than the e4300 because of it's 1066fsb, so I guess that was wrong. :rolleyes:

That's nice to know, this way I guess I can finally decide on buying a e4300 instead of a e6300 and begin playing with it's multi :banana:

Now on to some advice on the motheboard :) I intend to buy the 965p-ds3 from gigabyte, do you think it can reach some nice fsbs?

[urbanriot]

Intel Quad-pump the FSB, so divide 1066 by to get 266.

DDR numbers are multiplied by 2 because its already Double Data Rate, so divide that number by 2....533, which is technically 1:1 with the FSB.


Kenny, thanks for the warm welcome and quick response!

So, if I want to run my QX6700 at 3.6 GHz (for sake of argument) and did 300 MHz. x 12 multiplier on my 975XBX2, I would want to put "Memory Frequency" at 533 MHz and "Reference Frequency" at 266 MHz?

[Tonucci]

Theres an guide here, easy to understand:

http://forum.abit-usa.com/showthread.php?t=115915

[K404]

I heard from people that th e6300 is better than the e4300 because of it's 1066fsb, so I guess that was wrong. :rolleyes:

Now on to some advice on the motheboard :) I intend to buy the 965p-ds3 from gigabyte, do you think it can reach some nice fsbs?

I`m not 100% sure about the spec of the E4300....its a base FSB of 200 and a clock speed of 1.86GHz.... if it has a multiplier of 9, then its tempting to say that its better than the E6300 (which has a multi of 7) Base FSB doesnt matter if you plan to OC :D

I know a couple guys who bought the DS3 I think, no board is perfect but I *think* it does ok. The entire P5B series seems pretty good, thats all I "know" about from my own experience, sorry



So, if I want to run my QX6700 at 3.6 GHz (for sake of argument) and did 300 MHz. x 12 multiplier on my 975XBX2, I would want to put "Memory Frequency" at 533 MHz and "Reference Frequency" at 266 MHz?

I`m pretty sure that the RAM cant be lower than the FSB (1:1 is the lowest it can be) so the RAM would need to be running at at least 300MHz (DDR2-600)

The memory reference would actually be 266, (or..running 1:1) if the FSB was 266, but you have to hike up the FSB and the RAM will follow.

Hope this helps :)