Do I really benefit from a lower TDP CPU?

[watdahel]

I saw an Athlon 64 CPU with a TDP of 89 watts. I saw another Athlon 64 CPU with a higher clock speed but only 67 watts TDP! Will a computer with the latter CPU consume less electricity than with the former CPU? Does the fact that it's a higher clocked CPU(faster HyperTransport) mean the motherboard chipset is actually drawing more electricity and thus offsetting the lower CPU power draw?

 

[Cogman]

Yes, you do benefit from lower energy costs. The offset of your motherboard would happen ether way, remember that the clock frequency of the CPU is different from the FSB (a more determining factor in Northbridge power consumption)

Even then, the Northbridge is less complex then the CPU, thus, a higher clock speed changes its power consumption of the North bridge much less then the higher CPU clock speed.

 

[thedosbox]

Yes, you do benefit from lower energy costs.

From a financial perspective, the cost of buying a new CPU will probably outweigh any savings on his electric bill. Especially if he's not running his CPU @ 100% load all day.

 

[Cogman]

From a financial perspective, the cost of buying a new CPU will probably outweigh any savings on his electric bill. Especially if he's not running his CPU @ 100% load all day.

true, however, assuming similar costs for upgrading to either CPU will mean lower costs over all (even though, as you've pointed out, will probably be insignificant.)

The biggest reason for going with a lower TDP is the potential of a higher overclock with good cooling.

 

[Hacp]

You can just undervolt your cpu for the same effect.

 

[-Nintendork-]

Combining a low power cpu + undervolt is always a win.

Like my Athlon II X4


You can check this guide:
http://www.tomshardware.com/reviews/processor-power-management,2453-6.html