MORE STRESS ON 400MHzx7 THAN 266MHzx10.5?

andy5174

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Hi

I have a Pentium E6300@2.8GHz CPU with stock FSB and multiplier of 266MHz and 10.5x respectively. In order to match my FSB to DDR2-800 Ram, I intend to increase the FSB to 400MHz reducing the multiplier no. to 7x. Does this configuration have the same or much higher stress on my CPU compared to the stock setting?

Thanks.
 

andy5174

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Yeah, it's the normal thought. However, it will mean that AMD Black Edition should be able to overclock to infinity which is impossible.

In addition, I don't have a good HSF at the moment so my CPU could break down during the test if 400(much higher than 266)x7 does stress it. Hence, I am seeking suggestion from someone who knows or has experience in this kind of setup.

Thanks
 

TerminatorXT

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well I've done the same thing with my quad core

when I had the stock heatsink, I was at 266x9, I was scared to overclock, but I wanted to try 400x6, I saw like a 1C degree increase, but thats probably from the more voltage going into the motherboard... if you're worried, try 400x6 first check temps then try 400x7
 

randomizer

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It would place more stress on the chipset but won't really affect the CPU. You may need to increase your MCH/North Bridge/Chipset voltage.



I don't quite understand how you came to that conclusion. :??:
 

andy5174

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Regarding your previous post, there's no difference between 400x6 and 400x7 as the stress on FSB is the same.

However, your result shows that the stress on the 400x7 is about the same as the stock setting.

hmm... Should I try it or not? Difficult to decide. Perhaps I should steal my friend's Coolermaster V8 for testing, LOL :p

 
There is a difference between 400x6 and 400x7 - the stress on the FSB is the same, but the stress on the CPU core is greater at 400x7. The stress on the CPU core is the same at 400x7 and 266*10.5, but the stress on the FSB is greater, so the CPU as a whole will run slightly hotter. The stress on the FSB will remain constant if you try for 400x8, but the core will be under more stress, so the CPU as a whole will run hotter still. In most cases, there is a limit both to how high you will be able to get the FSB and how high you will be able to get the core. These are separate limits, but both of them exist (and therefore, you cannot overclock a CPU to infinity just because it has an unlocked multiplier).
 

TerminatorXT

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I wouldn't be scared, your choice if you want to try or not, but like I said, you will require more voltage through the motherboard which should be taken care off for voltage in auto
 

andy5174

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Thank you very much!!! This kind of answer is what I am looking for.

Besides, which has more effect on the CPU temp, FSB or multiplier?
 
Core speed and voltage have the largest effect (the effect from voltage is massive - it's probably the greatest effect, followed by core speed). Multiplier alone doesn't have much of an effect, other than that a higher mult usually means a higher core speed. FSB has a slight effect as well, but it is less significant than core speed and voltage.
 
Having a higher FSB (given the core frequency were to remain the same) means the cpu has more bandwidth to communicate with the outside world, in simple terms ... and yes there is a performance gain.

Whilst this had a fairly dramatic effect on the Netburst CPU's (going from 533 to 800 yeilded between 5% and 20% on some applications http://global.msi.eu/index.php?func=prodcpu2&prod_no=1244&maincat_no=1 ) the core2 line are far less senstive to the issue as their cache architecture is much more precise).

Rather than chasing higher FSB for the sake of the few percentage points you can gain may I suggest you opt for the best stable overclock that you can get without having to pump heaps of additional voltage into the cpu?

That way your getting the most for nothing, and I am sure you will get some extended life out of the cpu.

Alternatively clock the hell out of it and all the best - I don't take my own advice either.

;)