- Feb 22, 2006
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Ok this is going to be a little long but it should fill you in on all the details. If you just want to read my question its the 3rd paragraph from the bottom please at least read it.
I have been trying to oc my cpu and I ran into severe instability really quick, like 100mhz was the most I could get but even that wasn’t stable enough. I think I found my problem though. When I upped the htt reference clock last night to 220 (that is as high as I could go before it wouldn’t boot windows) and lowered my memory frequency to 180mhz I noticed a discrepancy in the memory frequency. (note my mobo doesn’t use dividers, but lets me select between 200 180 166 ect instead of 5/6 3/4 ect. so you know how I get my figures)
In post it registered the mhz as 202 but cpuz came up with 190 something although it should be 220*.9=198 (I know that it needs to be x2 bc its ddr but my post shows it as it is before it is x2. And I get the .9 by 180/200=.9 or 166/200=.83 later on).
Anyway to the point, I used cpuz to get my memory speed when ocing before, and well when cpuz showed my memory at 190 with 180mhz memory divider I thought I still had some room to up the htt reference clock more before dropping to the 166mhz memory speed.
Needless to say when I went farther than 220 with a 180mhz memory divider it made my ram (ddr400) unstable and was probably the cause of all my crashes where as I though according to cpuz the memory mhz should still have been fine so I dismissed it as my problem.
In my next step up in the oc is to take the LDT multiplier from 5 to 4 to keep the htt bus speed below 2.2ghz, (Overall HTT Bus Clock = Reference Clock * LDT Multiplier * 2), up the reference clock in 5 or 10mhz increments hopefully to 250mhz, drop the memory divider down to 166 (.83) so it will look like this
cpu- 11*250=2.75ghz (also up cpu voltage)
ram- 250*.83=207.5mhz (hopefully stable if not loosen timings and up voltage)
overall htt bus speed- 250*4*2=2ghz
My question is what do I trust, my post readout of 202 at 180mhz divider or the math 220*0.9=198? In my example above I used the math but I need to know what to trust to maintain stability.
Any help is greatly appreciated thanks for reading all that. Almost forgot, my pc stuff is in my sig but this is it again just in case.
cpu AMD 3500+ Newcastle core 2.2ghz 1.5v stock
mobo MSI K8 neo4 Platinum Sli
RAM corsair xms ddr 400 at 2-2-2-5 timings
And before anyone asks my psu is a 680w and I have sufficient cooling on the cpu so that is covered and not a problem
I have been trying to oc my cpu and I ran into severe instability really quick, like 100mhz was the most I could get but even that wasn’t stable enough. I think I found my problem though. When I upped the htt reference clock last night to 220 (that is as high as I could go before it wouldn’t boot windows) and lowered my memory frequency to 180mhz I noticed a discrepancy in the memory frequency. (note my mobo doesn’t use dividers, but lets me select between 200 180 166 ect instead of 5/6 3/4 ect. so you know how I get my figures)
In post it registered the mhz as 202 but cpuz came up with 190 something although it should be 220*.9=198 (I know that it needs to be x2 bc its ddr but my post shows it as it is before it is x2. And I get the .9 by 180/200=.9 or 166/200=.83 later on).
Anyway to the point, I used cpuz to get my memory speed when ocing before, and well when cpuz showed my memory at 190 with 180mhz memory divider I thought I still had some room to up the htt reference clock more before dropping to the 166mhz memory speed.
Needless to say when I went farther than 220 with a 180mhz memory divider it made my ram (ddr400) unstable and was probably the cause of all my crashes where as I though according to cpuz the memory mhz should still have been fine so I dismissed it as my problem.
In my next step up in the oc is to take the LDT multiplier from 5 to 4 to keep the htt bus speed below 2.2ghz, (Overall HTT Bus Clock = Reference Clock * LDT Multiplier * 2), up the reference clock in 5 or 10mhz increments hopefully to 250mhz, drop the memory divider down to 166 (.83) so it will look like this
cpu- 11*250=2.75ghz (also up cpu voltage)
ram- 250*.83=207.5mhz (hopefully stable if not loosen timings and up voltage)
overall htt bus speed- 250*4*2=2ghz
My question is what do I trust, my post readout of 202 at 180mhz divider or the math 220*0.9=198? In my example above I used the math but I need to know what to trust to maintain stability.
Any help is greatly appreciated thanks for reading all that. Almost forgot, my pc stuff is in my sig but this is it again just in case.
cpu AMD 3500+ Newcastle core 2.2ghz 1.5v stock
mobo MSI K8 neo4 Platinum Sli
RAM corsair xms ddr 400 at 2-2-2-5 timings
And before anyone asks my psu is a 680w and I have sufficient cooling on the cpu so that is covered and not a problem
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