better processor, less battery?

is it true that the faster the processor, the more it consumes power?


for instance, would a 2.16ghz Core duo consume more power than a 1.83ghz. i mean in a way it would cause a loss of 15minuts of battery life?

in tom's hardware review about the new core2duo processor, they're using a 2.33ghz merom, against a 2.16ghz yonah. and the battery life in the merom was only 10minutes better.

so i thought it was due to the higher clock speed.

for me, im looking for a laptop with the best battery life, so i think if my "theory" was right, then i might just stick to a 2ghz merom, it'll provide enough power, and better battery life.

 

Everything else being equal, yes, the faster processor will consume more power.

However, you can't compare different processor types this way though. A Core Duo can run circles around a Pentium 4 performance-wise, and still uses maybe a third of the power.

Sorted in order of power consumption, form best to worst, it'll look something like this:
Merom > Core Duo/Solo/Pentium M > Athlon 64 > Pentium 4
Within each CPU type, it's true that faster models consume more power.

 

If you're talking about a lower-clocked Core Duo versus a higher-clocked one - for example, the T2300E 1.66GHz vs. T2600 2.16GHz, they should both have the same battery life.

Yeah, I'd say that's right on the mark.

Mine is more of a specific statement, but all regular (non-LV/ULV) Core Duos have the same TDP - even if a higher-clocked one did consume slightly more, it would probably be so insignifigant that it would have no impact on the overall battery life.

 

The difference in real world usage will be negligible since these processors basically will most likely be running with Speedstep @ 1GHz and 0.95V on battery power, so whether you buy a T2300 or a T2700, the battery life under normal conditions will most likely be the same. The difference will only be noticable under full load where the T2300 might give slightly better battery than the T2700 and even in this case as well it will not be too noticable.

 

TDP is not representative of power consumption though. It is just the highest expected amount of heat that the heatsink must be able to dissipate. And yes, they tend to use the same TDP for an entire range of CPU's, just for convenience. That doesn't mean they use the same amount of power, it just means that the same heatsink will work for all of them, which is good news for anyone selling computers.

However, I have to admit it wasn't 100% accurate. There are differences from chip to chip in power efficiency. Some chips just run hotter than others, just like some can be clocked faster than others. This is a very minor difference though, but it's there. But if you take one chip, and run it at 2ghz and then 1.8ghz, you'll always notice lower power consumption on the latter. That's just how things are.

Of course, like miner said, with speedstep and such, it tends to reduce the difference, unless you run your CPU at full load.

 

That's what I was getting at. There should be a minimal difference in battery life, and it would be very rare that you're running at full tilt on battery all the time.