Is 4.5Ghz 50% faster than 3.0Ghz?

[Sparkyboy]

Apologies if this question is really basic.

All other things being equal, does a clock speed of say 4.5Ghz mean it's 50% faster than a clock speed of 3Ghz.

I know there are all sorts of issues regarding other hardware, and what you are running, but let's just assume everything else is unchanged. Forget number of cores, graphics, etc. I am running a mathematical computation that doesn't use graphics nor can make use of extra cores.

[David (PassMark)]

If you are talking about exactly the same CPU model, AND talking about an algorithm that doesn't use the disk, nor substantial RAM, nor the video card, AND the CPU doesn't overheat and throttle down, then yes data processed will scale with CPU clock speed.

[Anonymoose]

In the Real world however, these things never scale arithmetically. Because there are so many factors that affect real-world use, you can certainly approach that equivalent but will never reach it. In the real world, a 50% increase in CPU speed with a similar design CPU will probably net you a 35-40% increase in performance because when you ramp up that much other factors will almost always become a bottleneck - either memory, or bus speed or HDD speed, etc etc.

A good self-test comparison for many modern CPUs (laptops especially, but Core I-series desktops too) might be to compare their performance when fixed at various speedstep rates rather than floating CPU speed on-demand. You can download a number of widgets or tray utilities that monitor or manually control CPU speeds - just see how often it fluctuates up and down in regular desktop use!

Compare your CPU's benchmark performance when manually set to silent/power-saving mode vs. high performance. This would provide a good comparison of the same system with a CPU running at 1/3 or 1/2 its regular rate.

[mikedmonds]

How about a dual vs a single core at the same speed?
Thanks!
Mike

[David (PassMark)]

Dual core will always do better than a single core. The speed improvement will vary however from insignificant to almost 100% depending on the application(s) in use.