Turbo Boost

[riv3r]

So I've done some reading and get to somewhat familiarize myself with how a processor works. There are a few things I dont quite understand though. Many people say that very few applications are actually written to utilize all 4 cores in a quad core processor. Thus it would be advisable to get a dual core rather than a 4 core processor if what you are gonna do is just mostly surfing the web, mail and HD movies. (On a tight budget and not considering future-proofing). They would say the extra cores are a 'waste' because they arent gonna do anything but idle.

However, now lets compare a dual core 3.2GHz (if there is such a thing) processor with a 4 core 2.0GHz w/ Turbo Boost (something like the i7-920XM) and all else stays the same. Now ive read on wiki that turbo boost is some sort of 'dynamic overclocking' technology where if only 1 core is active, it overclocks itself to a max frequency of 3.2GHz. The more cores active the lower the max frequency.

LETS just say they cost the same, will the performance of the two processors be equal then? Will there be no 'waste' if the quad core has turbo boost technology?

Thanks!

 

[Idontcare]

Hi riv3r, welcome to the forums

If I have correctly understood the initial conditions and boundary conditions with which you have created your hypothetical scenario, then the answer is "yes" the performance would be the same.

 

[Cerb]

That is precisely why Intel has their processors go up in clock speed along with the number of cores and total cache size. That way, you can't decide, "a 3.5GHz dual-core would suit me better," because they don't make one. If you want the speed, you get the quad, and pay more, for CPUs in a similar TDP range (there's usually some overlap, but I think Intel has marketing guys that genuinely lose sleep over that, so not much overlap, at least per generation ).

The CPU models, however, are mainly advertised by the speed when all cores are active. But, with only 1 core active, yes, the performance would be the same (ninja'd).

All else being equal, though, you'd want a CPU from the last 1-2 years, rather than a 4-year-old one . A newer one will clock faster at a given TDP and core count, and be faster per clock, too. The short version of it is that the CPUs would run too hot if all cores were active at the Turbo frequency, but they can actually run that fast, so turning off those other cores gives thermal headroom for higher clock speeds, when the other ones aren't needed.

 

[FalseChristian]

4 cores is the minimum standard now. Shit, AMD makes an 8-core FX -8350. You'd be unhappy in the future when most new programs WILL utilize 4 or more cores.

You can grab an i5 4570K for under $300 that blows my i5 2500K out of the water. I paid about $300 Canadian for mine 3 years ago.