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skarphace

What Is The Multiplier Actually Doing?

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I appoligize for making so many threads withing so few days but this doesn't seem to apply to the other ones and apparently I have a lot of questions.

 

When I change the multiplier in my BIOS(apparently it's unlocked), what am I actually doing to the processor? I googled it, searched it here and all I get is that the bus times the multiplier = processor clock speed. But why? In electrical terms, could someone explain exactly what I am doing to my processor?

 

I just bumped my multiplier up and my processor apparently running cooler(according to PCProbe), is that all in my head?

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Yea, we all know what it does but he wants to know what it does...sorta hard to explain. He wants to know what is physically happening to his processor when he changes the multiplier.

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Yea, we all know what it does but he wants to know what it does...sorta hard to explain. He wants to know what is physically happening to his processor when he changes the multiplier.

579899[/snapback]

Yes, exactly. I'm supprised I can't find that anywhere.

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That's actually a really good question that I bet most people here couldn't really answer. It's easy to say "200 times 11 equals 2200mhz, you know?", but it's a lot harder to actually explain how the processor does it...

 

There's a decent explanation of how it really works on page 3 of the article that Nerm linked...

 

Really, the term "multiplier" is a weird way to think about it. It basically boils down to the cpu having two different speeds. Like an AXP 3200+ runs at 2200mhz, but the FSB is DRR 400, which is actually 200mhz. This means that the cpu can crunch whatever data it has in its registers and cache at 2200mhz, BUT, when it needs to interface with the memory, it can only do so at 200mhz.

 

When you think about what's actually happening, it's not taking the FSB and multiplying it by something really. The two speeds are totally separate. It's just using the multiplier to determine the internal speed with relation to the external speed. It's really very similar to how you would look at a memory divider/ratio. It's not easy to explain, but I hope that makes a bit of sense.

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Thanks for the article. I tried, but I guess my google skills are lacking.

 

So DDR is more of a descripter of the memory bus and not the actual memory... interesting... I get the general theme of it now. However, I can't help but think that it's almost pointless to have a high multiplier. The only thing it helps with is calculations that can be stored in the CPUs cache, no?

 

When I raised my multiplier, my arithmatic benchmarks did major jumps but things like 3Dmark only had a few extra marks. hm.

 

Thanks again guys. You know, I never realized how little I know about hardware until I tried overclocking...

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i say its like this

ever second my P4 3.0 GHz or 3,000 MHz.

now thats how many calculations it does per second.

I have a FSB of 200 MHz and mult of 15.

200 x 15 = 3,000

the FSB is how much the cpu talk with the rest of the computer.

my cpu talk to the 200 of teh computer at 200MHz.

the mult is how many times the cpu talk with the rest of the computer per cycle.

 

In one time frame.

(200 MHz talk with cpu | 200 MHz|200 MHz|200 MHz|200 MHz|200 MHz|200 MHz|200 MHz|200 MHz|200 MHz|200 MHz|200 MHz|200 MHz|200 MHz|200 MHz)

 

All that in one second.

 

if my P4 ran at 300fsb with 10 mult.

300 x 10 = 3,000 MHz

(300 MHz | 300 MHz | 300 MHz | 300 MHz | 300 MHz | 300 MHz | 300 MHz | 300 MHz | 300 MHz | 300 MHz).

 

I think it is better to have 300 in sted of 200 because when ever the 200MHz cyle ends, the data is ended early, and it has to be reproced the the next 200 MHz.

In the 300MHz cyle, the data can flow an etra 100 MHz.

after every 200 or 300 MHz frame, that data is sent to teh rest of the computer. Where it is processed by the gpu or ram or northbridge.

 

|200 MHz| 200 MHz| 200 MHz| 200 MHz|

---^ ----------^-----------^--------- ^

sent--------sent--------sent-------sent

 

|300 MHz |300 MHz |300 MHz |300 MHz |

---^ ----------^-----------^--------- ^

sent--------sent--------sent-------sent

 

here is a helper, i just thought it up.

you are some class work. but there is thing rule. you can only work 200 seconds, then you have to stop. and for some reason every time you stop, you forget what you were doing. So, you have to try to remember where you left off, example. you forgot how you were going to finish that sentence, so you earse it and rewite it. You are given 15 time frams of 200 seconds. or 3000 secs, or 50 minutes.

 

now the rule is defferent. the time frames ar 300 seconds long, but you only have 10 or them. 10 time frames of 300 = 3000 sec or 50 minutes.

Having 300 by 10 is better than 200 by 15, because you don't have to stop as much.

 

Man sorry i got kinda off topic but I made a good example

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