Bus speed help... please

jtcloud9

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I have an E6750 which I'm either gonna use in an X38 or P35 mobo, not sure yet which. The Proc runs at 1333mhz bus speed which I understand is 333mhz, quad-pumped. I will get a mobo that has a 1333mhz bus again which I understand to be a base clock speed of 333mhz, quad-pumped. My question is about the RAM bus speed relationship to the other two. I was planning on DDR2-800mhz which I understand is 400mhz dual-pumped? Now I see the base clock is higher for the RAM at 400mhz but if it cannot run at quad-pumped would I see better performance from DDR2 with a faster base clock? Or because it cant quad-pump 400mhz is plenty? Or am I just completely misunderstanding all of this? If anyone has any suggestions about the motherboard I would appreciate it. Thank you guys.
 

GSTe

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Rather than using terms like 'quad-pumped' etc, I find it easier when explained like this:

CPU FSB is 1333MHz, which is an actual speed of 333MHz
The RAM is DDR800 which is an actual speed of 400MHz

As it stands, the motherboard would run both at stock speeds using a 5:6 (CPU:FSB) ratio, or divider.

If you wanted a 1:1 ratio, which many people think gives best performance, you would have to overclock the CPU so its FSB was running at 400MHz the same as the RAM (you would need to use an aftermarket CPU cooler rather than the stock Intel one, and your chip would now be at 3.2GHz), or underclock the RAM so it was running at 333MHz the same as the CPU.

Does this make sense?
 

dashu31

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got a question though,

CPU FSB 800Mhz (E4500)
RAM DDR667Mhz (apacer)

i tried using the defaults still getting the sod..
i'm using the msi-p35 neo
 

jtcloud9

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Thank you for the reply GSTe. Thats pretty much what I was wondering, I guess the actual speed is whats most important. So I guess RAM cannot be quad-pumped at this time. I wonder how much slower the CPU and mobo would be without the quad-pumping, just using the actual speed.

So far I have an E6750, an Artic 7 HSF and an Nvidia 8800gt Alpha Dog edition. So now Im deciding on Mobo, ram and psu.
 

GSTe

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They would be a lot slower, quad pumped means that data is transmitted 4 times per CPU clock cycle, so probably 4 times slower. RAM can't be quad pumped, no. DDR means double data rate, and indicates that data is transmitted twice every clock cycle.

For the RAM I'd recommend any Crucial Ballistix as its pretty cheap at the minute and performs well. PSu wise I have a Corsair 620W HX and I love it, the 5 year warranty is reassuring too. For the mobo it depends on which chipset you want really. There are a lot of good P35 boards around, but several of the X38s are getting good reviews as well.
 
I just have the stock cooler on my e6750, but I wanted to run my RAM at 1:1 also. I raised the FSB to 400 MHz and dropped the multiplier from 8 to 7. I see no change in temps but I think I see a small performance improvement. I didn't run benchmarks though, so I'm not making any claims.
That would be a tiny overclock by the standards of this forum, but hey it works.
 

GSTe

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Does it even boot? Have you tried booting with just 1 stick of ram?
 

GSTe

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The cooler will allow the overclock, it's just the temps I'd be worried about.... I certainly wouldn't trust it myself when going from 2.66 to 3.2GHz, probably be looking in the high 60C range with a voltage bump.
 

dashu31

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it does boot. it just doesn't finish installing windows.
have the same problem before, with 1066FSB and DDR800mhz, it turns out my board doesn't support oc', so what i did was i turned down the ram to 667/533mhz.