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Originally Posted by unregistered
Cathar
you are aware of EK's testing, some of which yielded a higher OC with a higher CPU temp ?
you realize that with a resistor network you can model your bp ?
then you can back-calculate to get a fit for the different bps
but then you will need to address the thermal lag (capacitance) which affects the OC
gets too hairy for me when it is then necessary to characterize the magnitude and duration of the thermal transients
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EK? Am aware of my own testing though where I found the same thing, and promptly drew the ire of a certain forum admin leading to my banning from LiquidNinja's for daring to suggest such.
Basic summary of my prior testing which led me to this point:
Test 1) Cascade => Overclock stability quite dependent on flow-rate despite relatively small changes (<2C) in overall CPU temperature. By altering the water temperature I was able to ascertain that the overclock stability issue had a far wider effect than the overall CPU temperature. i.e. The high-flow scenarios would remain stable at 5C higher indicated CPU temperatures than the low-flow scenarios. Hypothesis: Uneven cooling effect across each cell resulting in hotter locations for the lower flow rates affecting overclock
Test 2) Thicker bp Cascade (essentially a copper Cascade SS without jet mods) => Overall CPU temperatures slightly higher and overclock stability was about the same at higher flow rates. Better overclock stability and better temperatures at lower flow rates than regular Cascade. Hypothesis: thicker bp provides a better "smoothing" effect
Test 3) Cascade SS => thicker bp than regular Cascade, jet modifications. Markedly improved overclocks in all scenarios (low/high flow rates), including holding higher overclocks at higher CPU temperatures. Improved overall temperatures. Undoubtedly some of the benefit seen was due to the silver used facilitating greater lateral thermal spread. Some gain also due to jet mods.
Basically all that is telling me that despite the original Cascade giving pretty good temperatures across the board, the actual temperatures weren't really telling the full story. Mind you, the original Cascade was giving me the best overclocks of all the blocks I tested it against, so I guess that's why I rested on it for a while.
Bill, I'm sure that a test setup can be made to measure all this. Electronics aren't my strong point though as I'm a relative noob in that area. Sure, I can find my way around a multimeter, but proper part selection and setup and control is something I'd need assistance with.