3rd generation vs 4th generation

Question

i was looking for the difference between 3rd generation and 4th generation processors. can any one tell me what plus points are with 4th generation processors if any.

is a 1.6GHz 4th gen processor is better than 3rd gen 2.4GHz?

Thanks

Answer 1

It's been a long time since the frequency of a CPU was a reasonable metric to compare performance of difference CPUs Megahertz_myth. Several new technologies are used to increase performance besides the frequency such as muiltiple cores, SIMD, Instruction level parallelism.

One metric to gauge performance is the peak FLOPS (floating point operarations per second). There is an excellent answer (to a question I asked) FLOPS per cycle for sandy-bridge and haswell SSE2/AVX/AVX2 which shows the peak FLOPS per clock cycle for several different processors. Haswell (4th generation) added FMA3 support which doubled the peak FLOPS compared to Sandy (Ivy) Bridge (3rd generation). It's rather annoying that Intel waits so long to introduce their performance desktop and server CPUs which are still 3rd generation since 4th generation has doubled the peak FLOPs.

Besides peak FLOPS one might be interested in the peak integer operations per second. Haswell also added AVX2 which added integer support to the 256-bit AVX registers. This double the peak integer operations per second compared to 3rd generations.

Lastly, although Intel has had IGPs for quite some time the IGP only got interesting with Haswell. Particularly the Iris Pro (HD5200). It's the first time the Intel IGP is worth taking seriously in my opinion (and it's going to get a lot better with Broadwell). In addition some Haswell CPUs have a Level4 128 MB cache.

You can see how serious Intel is taking the IGP by looking at how much Silicon they use for the IGP. See (this image) (http://download.intel.com/newsroom/kits//core/4thgen/gallery/images/4th_Generation_Intel_Core_Dual_Core_Hero_HR.jpg) for a 2 core Haswell with HD5000. The IGP uses over 50% of the silicon! Even for the desktop processors with GT2 (e.g. 4770K) the IGP uses over 30% of the silicon (which is wasted circuitry for most people).

In summary the technologies most interesting (IMHO) for 4th generation are FMA3, AVX2, 128 MB L4 cache, and the Iris Pro IGP.

Answer 2

While the 4th generation has less GHz, it was designed with laptop in mind. Thus, it consumes less power (more load / cycles, more heat generated by the processor and with temperature-regulated fan, more power will be consumed not just by the processor itself but also by the fan).

In addition, the 4th generation has extra feature - turbo boost, which, using an analogy, would be like nitro on a sports car, but the difference is that it is still regulated by the processor's thermal and current limits. It gives you a boost to meet demand requested by OS. Nitro, on the other hand, is regulated by the driver - you could pump as much in the engine until the engine blows out (Ok, there is still nitro regulator, if installed).

Either, it is meant to provide a short burst regulated still by the processor's thermal and current limit to meet sudden demand by the operating system dynamically.

The 4th generation has an integrated GPU. So, if you wish to have your own dedicated GPU, go for the 3rd generation. If not and if getting a laptop is what you intended I would suggest getting the 4th generation, it will be quieter (personally a plus; imagine sitting in a library and your fan is oozing out heat and making noises) and consumes less power. Just my 2 cents.

Answer 3

The 3rd gen is faster but more power consuming