OC Settings And Clock Speed Table
The table below lists all clock speeds and settings that we used for this article. Please note that we had to switch off the Turbo Boost feature above 3.2 GHz, as the resulting maximum clock speed would have exceeded the highest reliable speed of roughly 4.2 GHz. Here is an overview of the resulting clock speeds realized when you increase the system clock without modifying the base multiplier (the first column is with a 20x multiplier), but with Turbo Boost enabled (columns with multiplier 21x and 24x):
|Target Clock Speeds Core i5 Overclocking||Default Clock Speed at 20x||Max. Turbo Boost Speed with 3 or 4 Active Cores (Multiplier+1)||Max. Turbo Boost Speed with 1 or 2 Active Cores (Multiplier+4)|
|133 MHz BCLK||2,666 MHz (20x multipler)||2,800 MHz (21x multiplier)||3,200 MHz (24x multiplier)|
|150 MHz BCLK||3,000 MHz (20x multiplier)||3,150 MHz (21x multiplier)||3,600 MHz (24x multiplier)|
|160 MHz BCLK||3,200 MHz (20x multiplier)||3,360 MHz (21x multiplier)||3,840 MHz (24x multiplier)*|
|170 MHz BCLK||3,400 MHz (20x multiplier)||3,570 MHz (21x multiplier)*||4,080 MHz (24x multiplier)*|
|180 MHz BCLK||3,600 MHz (20x multiplier)||3,780 MHz (21x multiplier)*||4,320 MHz (24x multiplier)*|
(*) These settings were unstable without application of additional processor core voltage, which we avoided.
Regardless of possible margins in the thermal envelope of the processor, our Core i5-750 did not operate higher than about 3.7 GHz without a voltage increase. As a result, we found that a 160 MHz base clock was the maximum stable setting we could use with Turbo Boost enabled and without increasing voltage.
Certainly, you can increase the processor voltage in an effort to move default and Turbo Boost clock speeds further up, but this would also result in decreased efficiency in all operating states. Hence, a 160 MHz BCLK with a 3.2 GHz nominal speed and a Turbo Boost speed of 3.36 GHz for three or four cores and 3.8 GHz for one or two cores was the maximum here.
Clock Speed Table
|Core i5-750||3,000 MHz||3,200 MHz||3,400 MHz|
|Base Frequency||150 MHz||160 MHz||170 MHz|
|System Idle Power||71W||71W||72W|
|CPU-Z VT idle||1.224V||1.224V||1.224V|
|CPU-Z VT load||1.176V||1.176V||1.176V|
|Fritz Chess Benchmark||9,167||9,642||9,981|
|Core i5-750||3,600 MHz||3,800 MHz||4,000 MHz||4,200 MHz|
|Base Frequency||180 MHz||190 MHz||200 MHz||210 MHz|
|System Idle Power||73W||75W||79W||122W|
|CPU-Z VT idle||1.256V||1.328V||1.448V||1.512V|
|CPU-Z VT load||1.208V||1.272V||1.384V||1.44V|
|Fritz Chess Benchmark||10,405||11,008||11,501||12,157|