Conclusion

Intel has a solid track record for releasing new processor steppings that deliver the same performance at reduced power levels. Prior-generation S-model Core 2 processors allowed select processors to run at decreased voltage levels in an effort to reduce system power consumption. But with the Core i5-750S, the tune is changing.

The Core i5-750S only reaches its lower power levels through a solid reduction in nominal clock speed and a limitation of the Turbo Boost feature, all in an effort to keep the processor well within the specified thermal envelope of 83W. People looking for a Core i5 quad-core product that works within certain power consumption restrictions will appreciate the Core i5-750S, even with its price premium. While the regular model costs $196 and up, expect to spend roughly $259 on the “power optimized” version. Though that's a smaller price hike versus past Core 2-based S-class CPUs, it's still a significant premium for a slower component.

The new chip only delivers its benefits if low power is the only criteria. Everyone who still wants performance or even efficiency, measured in performance per watt, will probably be as disappointed as we were. Intel decided to cut back clock speeds to deliver a low-power processor, but the firm doesn’t seem to bothered that the S-model processors actually deliver worse power efficiency than the regular models. We believe this should not be the case.

The fact that you cannot rely on a processor’s model number anymore to be able to estimate its performance or clock speed is pretty discouraging. It forces almost every user to look at the specifications before making any move. Car manufacturers such as BMW and Mercedes stopped matching model numbers with engine sizes long ago, so perhaps we should be tolerant enough to accept this. However, spending a lot of money on a supposedly energy-efficient product, only to see it spanked by the regular product in key tests, leaves a bitter aftertaste. You decide what the S means now.