Why do some Xeon processors use so much power?

[diep]

6700k is a chip with just 4 cores and tdp of 91 watt. non-server processors tdp's i'm not so sure how 'strict' those are if you measure them. Even then that's a whopping 23 watt for 1 core.

Compare with quad core ARM 1.4 - 2.0 ghz that's 2.2 watt under full load and older process technology than the 6700k.

Electronics and physics aren't my strongest point.

It's the lack of good software, read good OSes that do not multithread/multiproces in a very good manner, which causes us to be using very high clocked cpu's with few cores, instead of much lower clocked cpu's with a bunch of cores at a much lower TDP.

I would argue ARMs has completely replaced x86's for the masses. Many nowadays only own a mobile phone and no longer a personal computer and usually an ARM in that phone!

I explicitly mentionned quadcore ARMs as they use not that many transistors like x64 with AVX is doing :)
If you have software that runs very well SMP then a lot simpler cores will always beat todays overcomplex cores.

A chip without fp64 at all would be really interesting to produce with 1024 cores on a single chip.

Except i do not see it happen any soon because the OSes simply favour high clocked CPU's as well as most applications do.

To pay for those expensive factories that produce cpu's, a price of 10-20 billion dollar isn't abnormal for a factory, which is the 2nd law of Moore as intel calls it - price of each generation of process technology in a new factory leading to a doubling in price to build that factory. So i would argue that making cpu's ever more complex by keeping adding all sorts of instructions is a waste of silicon anyway.

The fundamental problem seems to be: no one pays for better software!
So the software improvements there really go duck slow...

Eventually we'll get there!

[henryzz]

I was under the impression that power usage was O(f * V^2) of cause higher frequency requires higher voltage(perhaps giving O(f^3) in some ranges of f).