TDP of IB vs. IB-E

[appletree]

Please can anyone explain to me why
3770K is 77W and 4820K is 130W - while both being virtually the same chips ? (well IB-E has more L3 cache but doesn't have GPU)

http://www.cpu-world.com/Compare/586/Intel_Core_i7_i7-3770K_vs_Intel_Core_i7_i7-4820K.html

Or how can the 6 core version of IB-E be also 130W TDP ? (the same as the quad version) Surely the 130W TDP of 4820K can not be based in reality, or can it ?

 

[Cromulent]

The most likely reason is that the 4820K is actually a 4930K with two cores disabled.

 

[appletree]

But will the 4820K output more heat than 3770K on the same frequency and voltage ?

 

[Orcvader]

Reasons for a higher TDP:

Higher stock speed (3.5ghz vs 3.7ghz)
More cache
Quad channel memory controller + higher memory speeds
Bigger PCI-E controller for double amount of lanes

There are other various reasons but IB-E is basically a more "heavy" chip designed with bigger bandwidth interface to other components of the PC.

The 4820K probably goes over the 77W mark hence why they label it 130W, it may not be exactly that high but Intel wanted to keep it simple by not putting too many different TDPs on the market.