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Energy Saver, "Better Performance"

D

dpk

macrumors newbie
Original poster
Mar 17, 2008
22
0
Under "Energy Saver" you can choose "Better Energy Savings", "Normal", and "Better Performance". As you pick each of these options, the only visible change is the computer sleep timer and the display sleep timer. Does anything else change?

The main thing I'm wondering about is the difference between Normal and Better Performance. According to this screen, the main difference is that in Normal mode, the computer will go to sleep in 15 minutes. In Better Performance it'll never go to sleep. Is the better performance truly just related to the amount of time it takes to wake up the computer, or is there something more going on, such as CPU speed?

If it's more, can anyone quantify exactly what changes?

I've searched around for this, but I haven't found the specific answer; I've mostly found comparisons between multiple computers (heh). Posting in the MBP forum because I have a MBP. I assume that'd change the exact speed values, if they are changed.
 
They do not make a different in "performance", only display/hard drive sleep settings etc. It's probably best for you to set them exactly with a custom setting anyways.
 
I believe this also controls how the processor throttles itself to lower energy consumption along with other aspects such as timings for when other hardware components power down.
 
iCeFuSiOn said:
I believe this also controls how the processor throttles itself to lower energy consumption along with other aspects such as timings for when other hardware components power down.
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hmmm really? I thought it would only change the time before a hard drive would spin down and not affect the clock speed of the CPU/GPU. I knew it did with the G4's and maybe G5's but with the MBPs...?

edit: that is not to say that the CPU will not slow itself down when it is almost running out of battery power, but i don't think it can be changed based on the settings (only if battery is taken out or computer is unplugged).
 
PkennethV said:
hmmm really? I thought it would only change the time before a hard drive would spin down and not affect the clock speed of the CPU/GPU. I knew it did with the G4's and maybe G5's but with the MBPs...?

edit: that is not to say that the CPU will not slow itself down when it is almost running out of battery power, but i don't think it can be changed based on the settings (only if battery is taken out or computer is unplugged).
Click to expand...
Well, in the Santa Rosa MacBook Pros, the chipset has the ability to lower the clock speed independently on each core I believe, so like I said those settings may very well control some of this functionality. I'm more familiar with it on the Windows side rather on how Mac OS X controls power management, but I'm sure someone else would know a lot more about this. If you're interested, you could take a look at the pmset command, this controls certain power management aspects.
 
May it be that you can't really control processor speed with the Santa Rosa chipset? In my powermac G5 I had an option to select "economic" , "automatic" and "high performance" (or something like that) that really clocked down the processor. In my new MBP there is not that control anymore, so maybe the chipset is able to control this parameters according to the power source... it's just speculation.
 
Is there a way to view the "current" processor speed? Maybe I can just run a shell script that checks it periodically, and compare the results when running under each profile.
 
The processor downclocks if its idle, no matter its on AC or battery, high performance or better battery. Once there is load, the clock speed adjusts as accordingly. Thats why u see a slight lag in things like cover flow for the first second u use it, then it will be smooth after that 1 second.
 
lauph said:
The processor downclocks if its idle, no matter its on AC or battery, high performance or better battery. Once there is load, the clock speed adjusts as accordingly. Thats why u see a slight lag in things like cover flow for the first second u use it, then it will be smooth after that 1 second.
Click to expand...


Yes it does. But I think the OP is wondering if changing energy saver settings will limit the amount of throttling.
 
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