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setting and using dividers properly

post #1 of 4
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ok, still new to the whole oc'ing concept but im learning slowly but surely. need some info on dividers.

my ram maxes out at 230, but my cpu can handle much more than that. so, i need to use a divider to get the most out of it, correct?

well, exactly how do i do this? do i change the DRAM clock setting from 3200 to 2700? is that all there is to it?

heres what ive done so far:
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My System
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amd 3700+ san diego abit kn8 sli evga 7800gt 2 x 1gb gskill ddr 500 
OSMonitorKeyboardPower
xp pro 19 inch cmv lcd logitech g15 550 sunbeam nuuo 
CaseMouse
ultra wizard logitech mx 510 
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post #2 of 4
Quote:
Originally Posted by whataboutbob?
well, exactly how do i do this? do i change the DRAM clock setting from 3200 to 2700? is that all there is to it?
Roger Roger. Oh and you might want to bump the voltages...maybe...if it is unstable at a higher clock.

Es
 
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Intel i7 3820 Asus P9X79 Pro MSI GTX 580 Lightning G.Skill Ares 8GB 
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OCZ Agility 3 60GB Corsair H100 6 case fans Ubuntu 10.10 
PowerCase
Rosewill Capstone 750W Corsair 400R 
CPUMotherboardGraphicsRAM
Pentium P5 Shuttle Socket 4 Diamond Stealth Samsung 4MB 
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Western Digital 160MB x2 speed CD ROM Intel OEM Windows 3.11 
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CRT 101 Keyboard Who knows Off white PC case 
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post #3 of 4
You can change ram dividers by going into the BIOS's Frequency and/or Advanced Chipset menu depending on what bios you have.

Usually you have to specify "manual" to override and change ram dividers. Ram dividers will look something like this: 2/2, 2/1.83, 2/1.66, 2/1.5, 2/1.33, 2/1. Ram dividers enable the ram to operate at a fraction of the FSB.

An example would be if you set your FSB to 266 (like me), the ram would be trying to run at 266*2=532MHz wich is impossible for cheap DDR400 ram.

So setting a ram divider of 2/1.5 ensures that the Ram is running at 66% of the FSB.

So 266 FSB (2/1.5=1.33) means 266/1.33=200. There you go. A 2/1.5 Ram divider will run the RAm at 66% of the FSB enabling the Ram to stay at it's stock speed.

But since your Ram maxes out at 230 then that means DDR460, so

2/1.66=1.20, 266/1.20=220=DDR440 (close enough) And you could even raise you FSB to 275 if you give the CPU enough voltage.

275/1.20=229*2=DDR460. This is merey a guide to help you understand the concept behind Ram dividers and what they actually mean. Actually results may vary depending on your system.

It may seem complicated but there is usually a "DDRXXX" readout in realtime as you adjust the FSB within the BIOS. Then when you set the ram dividers the "DDRXXX" value will change letting you know what the effective DDR speed will be once you apply the overclock. This removes the guesswork and makes it alot easier.
post #4 of 4
After looking at your thumbnail is looks like you can (and should) raise you vcore to get a further overclock. Just monitor your temperature to make sure it stays below 50C for saftey's sake. I don't really know how much experience you have with overclocking utilities but you should benchmark your system to know if it is relatively stable I usually do a Sandra CPU arithmetic/multimedia, Memory bandwidth/cache benchmark to make sure the system doesn't crash. Not enough voltage WILL make your system crash during benchmarks if it even boots at all.

Just make sure you keep an eye on those temps. AMD's really don't mind being fried to death. If they did, they would automatically lower thier multiplier when they overheat which they don't, but if your motherboard has thermal throttling and or thermal shutdown protection I suggest you turn it on untill you know your temps/voltages are safe.

You ram is only running at 200MHz, you can raise your fsb even more but I would give it the CPU bit more vcore 1.5 volts seems about right. You might also be able to increase the vdimm (ram voltage) to get tighter timings. Mines at 1.5 3 2 5 because I upped the voltage .2v.

Usually there will be a trade off between high RAM bandwidth and tight timings. Either on or the other unless you have high end ram.
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