That's kind of a loaded question. You can't really compare different architectures just by their clock speed. I've got an i7 2600K running at 4.5GHz, but depending on the work load, a 4GHz Power8 from IBM could trounce my intel cpu.

And you are missing a lot of CPUs in that list. The MIPS family (still in heavy use today), the POWER series, ARM, Hitachi SHx, and even older generations like 8086-80486, 68K series from Motorola, Z80, 6502 (and variants).

*EDIT*

APUs are basically a CPU, GPU, Memory controllers and maybe the northbridge of the chipset merged onto a single die. One nice detail is how well the powergating works, when you aren't using the device for much, thereby saving power. Another appeal is the whole concept of HSA, which APUs are supposed to enable.

i did'nt include pre coppermine processors because Feipoa did some benchs about those and its very clear. Besides im interested in processor's that can actually outperform something that is selling new (atom for example)

im saying in general use. Several times i wondered how the f*** an AIO can come with something like an AMD E-350 wich performs like a pentium 3 in all the ways

I would say that Intel's latest processors would offer the highest performance per watt.

philscomputerlab wrote:

I would say that Intel's latest processors would offer the highest performance per watt.

I agree. At least up until 'Ivy Bridge', not sure if 'Haswell' continued the trend.

Living wrote:

i did'nt include pre coppermine processors because Feipoa did some benchs about those and its very clear. Besides im interested in processor's that can actually outperform something that is selling new (atom for example)

im saying in general use. Several times i wondered how the f*** an AIO can come with something like an AMD E-350 wich performs like a pentium 3 in all the ways

Ah, I misunderstood the initial question. Sorry about that!

One thing to bear in mind is to take into account the different architectural difference between the chips, not just comparing clock speeds. Often times, there are improvements under the hood that increase efficiency, number of instructions dispatched/retired per clock, how the prefetch, instruction decoders, and how many instructions can be "in flight" at the same time, pipeline stages, cache size/coherency, etc...

Just comparing clock speed is like comparing oranges to durians. They don't always reflect what's happening under the hood.

And you might want to include more than just intel chips. pound for pound, the POWER series can trounce certain chips, while operating at lower clock speeds.

+1 to what ElectricMonk said. For example putting NetBurst at the bottom isn't entirely accurate - it will outperform Pentium 3, Pentium M, etc when it can leverage SSE2 and especially SSE3, but straight up ALU synthetics will not reveal that. It really depends WHAT you're having the CPU do as far as what's most efficient or powerful in a given setting. If you had a specific benchmark or usage scenario it would be easier to compare a variety of CPUs, but it still wouldn't be an absolute "this is better than that" kind of thing.

Even an Atom can be faster than Coppermine at the same clock if your benchmark/app benefits from higher memory bandwidth or SSE2 (or even SSE3). And that's the classic Atom, not the out-of-order Bay-Trail or similar models.
Of course it depends on how you consider multithreaded performance.

Tom's Hardware has an interesting comparison of P4 (2.2GHz and 3.2GHz) against two Atom models. The Atoms look very good here, and the result isn't even adjusted for clock rate yet.

AMD started to fall behind way back during the days of the Core Duo and especially Core 2 Duo even though they still very good for the money but ever since the i7/i5 era AMD can't compete in the high and mid range anymore. People still buy into AMD thinking they are getting the best bang for their buck (looking at current gen gamers) never realize the hidden costs such as having no other choice but to buy boards that can handle the 200W+ when doing any real overclocking ect. AMD's APUs are good except for the lacking memory controller and rising cost of performance DDR3. Can go on but too lazy to bother and if there was a debate by the time it was over the sun wold have ran out of hydrogen.

The Athlon/XP series was quite efficient, especially compared to the P4. As others said the Core i5/7 series is also very good. Its actually a bit worrying AMD is that far behind.

Darkman wrote:

The Athlon/XP series was quite efficient, especially compared to the P4. As others said the Core i5/7 series is also very good. Its actually a bit worrying AMD is that far behind.

When it was working it was a fine CPU, but in practice it wasted a lot of power. The systems from that time often came without any working* idle power saving. When idle at the desktop it remained at 100% CPU usage.

*The CPU supports STPGNT and HLT allright, but many motherboards will not work properly when using this.

gerwin wrote:

Darkman wrote:

The Athlon/XP series was quite efficient, especially compared to the P4. As others said the Core i5/7 series is also very good. Its actually a bit worrying AMD is that far behind.

When it was working it was a fine CPU, but in practice it wasted a lot of power. The systems from that time often came without any working* idle power saving. When idle at the desktop it remained at 100% CPU usage.

*The CPU supports STPGNT and HLT allright, but many motherboards will not work properly when using this.

Well, there are those "software cooling" apps. I use CoolON with my AXP.