Rookie Overclocking question

leeland

Diamond Member
Dec 12, 2000
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ok so I am a beginner at overclocking have had read multiple posts with instructions on how it is done and what settings are to be changed...ect.

I have the latest BIOS from asus for the board and am running 4 GB's of RAM PC-6400 800 Mhz

I have a couple of questions....

If the FSB is 266 x 4 for a total of 1066 but the RAM which I have is PC-6400 800 MHz and I leave everything as stock then the RAM so that means it is NOT a 1:1 FSB/DRAM ratio correct and is termed "asynchronous"?

I am assuming that it is optimal to run in a 1:1 ratio? or does it really matter?

From the posts I have seen I have started out by changing some "key" settings in regards AUTO to what is recommended either from the manufacture website or online...

* Set my memory voltage to 2.0V (Manufacture Recommendation)
* Set the CPU voltage to 1.25 (checked the BIOS monitor and Z-CPU and went in the middle)
* Tried to set the manufacture recommended timings for my RAM 4-4-4-12 but it wouldn't boot on the manual settings, had to increase it to 5-5-5-15.

once I did that it booted fine and that is where I am at right now.

I have tried a couple of times to follow the posts about setting the FSB higher to achieve the 1:1 ratio and also increasing the CPU speed but I think I am failing...

On the asus board I think if I don't manually pic a DRAM frequency it just increases the clock speed as I increase the FSB because they are linked...I believe the term is bootstrap? Please correct me if I am wrong. Do I have to manually modify the DRAM Frequency setting in correlation to the Multiplier and the FSB so they some how magically match?



I left the DRAM frequency as auto...increased the FSB to 300 and rebooted...came up fine but when I went into Z-CPU it showed the DRAM frequency at 450...don't think that is what I wanted...


SO before I F anything up, I set everything to stock and decided to post this.

I am curious how the correlation to the DRAM Frequency setting and the FSB & Multiplier part works so I could achieve a 1:1 ratio if that is indeed optimal.


Sorry for the long post just trying to get it all out there right away...

Any help is appreciated.


Thanks,
Lee
 

brblx

Diamond Member
Mar 23, 2009
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your memory is 800mhz DDR. 400mhz bus speed, doubled, equals 800mhz. your memory is capable of supporting a 400mhz FSB when using a 1:1 divider.

the quad-pumped 1066 number is irrelevant. your FSB is 266mhz, which means your ram will run at 533mhz. 'asynchronous' refers to running memory with a divider that is not 1:1- to get your memory to actually run at 800mhz with a 266 FSB requires a 2:3 divider (266:400). someone can feel free to correct me, but i've yet to see anything showing any real gain from running memory faster than the FSB. and 1:1 will ensure stability. so, in your BIOS, you should use the memory speed that's twice your current bus. if your current bus speed is 300, pick 600. do not use an 'auto.' what you're seeing right now is your board still using a 2:3 divider, running your memory 50% faster than the bus. at 450mhz (900 effective), your RAM will not like this.
 

leeland

Diamond Member
Dec 12, 2000
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I finally found another post that described the same thing (guess I am not the only tard :D). Anyways once I grasped the concept that you just explained above I changed the BIOS DRAM Frequency to PC-533 and slowly moved the clock speeds up in increments. I got to 355 (around 3.2 GHz) with a VCore of 1.35 and was able to run two PRIME95 instances for over a couple hours with the temps only reaching 47C based off of CoreTemp and no errors on PRIME95

I guess I wasn't trying intentionally to run my memory at a higher clock speed than what it was designed to I was trying to get it in sync with the CPU (if that make sense) so it was a 1:1

I suppose I could drop the divder / multiplier to 8 and set the FSB to 320 and be at the same speed and have the RAM technically running at a FSB of 400 MHz...which would get me what I was trying to do.

Does it matter that much though? Is it a loss to run the memory at a slower FSB?

Thanks,
Lee
 

Schmide

Diamond Member
Mar 7, 2002
5,581
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Originally posted by: leeland

Does it matter that much though? Is it a loss to run the memory at a slower FSB?

Thanks,
Lee

No! At most 1-3% point difference either way. When overclocking the stability of 1:1 is worth more than any gain you may receive from a higher memory clock.

At those temps you should try running, 1:1 memory at 400fsb x 9 = 3600mhz
 

elconejito

Senior member
Dec 19, 2007
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www.harvsworld.com
Watch out for FSB "holes" on this motherboard. meaning, if you get stuck at some FSB speed and you find yourself pumping ridiculous amounts of voltages to get stability, instead of dropping back down you should actually go forward. I used to have this board, and I ran it at FSB 358mhz. It was completely unstable at 360, but was stable again around 380-390. It ran too hot for me though at that speed so i notched it back down to 358 (3.2Ghz) and I was very happy there.
 

looper

Golden Member
Oct 22, 1999
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See our rig listed below. Which bios are you using? The later the better...
 

leeland

Diamond Member
Dec 12, 2000
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I am using the latest BIOS on this board I believe it is 1238...

I got it running at 355 for the FSB and get no errors when I stress test it at a VCore of 1.35 but I get very RANDOM BSOD...I am not doing anything except the internet and maybe copying a file and boom it happens...

what are acceptable temps under load and what would be a comfortable VCore to stick to?
 

fffblackmage

Platinum Member
Dec 28, 2007
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At least for me, when OC'ing my E6320, I don't get errors in stress tests, but I get random BSODs while idling on the desktop, and not while gaming gaming, oddly enough. Increasing cpu voltage fixed that for me.