Just a useless curiosity... what is your MacBook or MacBook Pro nominal speed / idle speed (supposing you have Core Duo Temp or something similar installed)? Mine (MB) is 2.0/1.5 Ghz. (Intel iMacs and Mac Minis speeds well accepted).
Mine idles at 1.5GHz as well. Is there a reason it doesn't throttle back way lower than that? I have XP machines that will drop down to 500MHz when idle. Is there that much going on under the hood when it's idle that it needs to be running at that speed? I would imagine dropping down to 500MHz or lower while idle would give it a chance to cool a bit as well as save some power.
Dunno why some XP machine idle down to 500Mhz. Maybe MacBooks are stuck to 1,5Ghz from firmware. Can you imagine how any complaints from the Mac community if a machine stucks down to 0,5Ghz (even if) in idle...?
Dunno why some XP machine idle down to 500Mhz. Maybe MacBooks are stuck to 1,5Ghz from firmware. Can you imagine how any complaints from the Mac community if a machine stucks down to 0,5Ghz (even if) in idle...?
Yeah... you have a point there... even in the Windows world... I see comments all the time about people wondering why their 3.5GHz processor is showing up as 1.5GHz. Then you have to explain the whole power management thing and what the different settings in XP actually do.
There is no Pentium M/ Core Duo that is able to throttle down to 500 MHz... the lowest is 600 MHz on 100MHz (400 QDR) FSB ULV Pentium Ms. Some companies also employ clock throttling for the FSB to bring down the CPU clock rate even further, but that does not decrease power consumption. Generally, the lowest FSBS multiplier that Pentium M/ Core Duo will do is 6.
So 166 MHz (667 QDR) FSB Core Dou will turn at ~1 GHz at its lowest setting.
I would suspect that the Macs run 1.5 GHz at idle has to do more with power management driver rather than background tasks.
There is no Pentium M/ Core Duo that is able to throttle down to 500 MHz... the lowest is 600 MHz on 100MHz (400 QDR) FSB ULV Pentium Ms.
I don't know about Core Duo, but I have seen my wife's Dell with a 1.6 GHz P-M dropping down to 32 MHz when idle on battery power. Plugging in a USB mouse however ups this to 600 MHz. In any case, the machine responds so quickly to user demand restoring the CPU speed, that the user would never notice that the CPU was clocked so low when idle without monitoring it with a dedicated utility.
By the way, how do you check in an Intel Mac the CPU speed at any time?
Really? I think everyone else on this thread is saying that they've never seen their MacTel go below 1.5. [/B]
No, mine definitely goes down to 1.00 GHz a lot* when all I do is write / chat / etc.
*) According to MenuTemperature 1.1a2, which gets its readings from SpeedIt.
In fact, I added a little NSLog() line in it to double-check.
Code:
2006-06-21 12:06:23.665 MenuTemperature[665] 1333
2006-06-21 12:06:24.456 MenuTemperature[665] 2000
2006-06-21 12:06:25.956 MenuTemperature[665] 1000
2006-06-21 12:06:27.456 MenuTemperature[665] 1333
2006-06-21 12:06:28.956 MenuTemperature[665] 1500
2006-06-21 12:06:30.456 MenuTemperature[665] 2000
2006-06-21 12:06:31.956 MenuTemperature[665] 1333
2006-06-21 12:06:33.456 MenuTemperature[665] 1500
2006-06-21 12:06:34.960 MenuTemperature[665] 1667
2006-06-21 12:06:36.456 MenuTemperature[665] 1500
2006-06-21 12:06:37.956 MenuTemperature[665] 1333
2006-06-21 12:06:39.456 MenuTemperature[665] 1500
2006-06-21 12:06:40.956 MenuTemperature[665] 1667
2006-06-21 12:06:42.456 MenuTemperature[665] 1667
2006-06-21 12:06:43.960 MenuTemperature[665] 1833
2006-06-21 12:06:45.456 MenuTemperature[665] 1000
2006-06-21 12:06:46.956 MenuTemperature[665] 1333
As you can see, it occasionally goes down to 1000. While I don't see 1167 anywhere, every other value seems covered in this short sample.
Or, I can do the same without MenuTemperature altogether.
Code:
ataraxy:~ chucker$ while true; do sysctl kern.cpu_currentfreq; sleep 0.5; done
kern.cpu_currentfreq: 1500
kern.cpu_currentfreq: 1667
kern.cpu_currentfreq: 1500
kern.cpu_currentfreq: 2000
kern.cpu_currentfreq: 1500
kern.cpu_currentfreq: 2000
kern.cpu_currentfreq: 1833
kern.cpu_currentfreq: 1667
kern.cpu_currentfreq: 1500
kern.cpu_currentfreq: 2000
kern.cpu_currentfreq: 2000
kern.cpu_currentfreq: 2000
kern.cpu_currentfreq: 1500
kern.cpu_currentfreq: 2000
kern.cpu_currentfreq: 2000
kern.cpu_currentfreq: 1667
kern.cpu_currentfreq: 2000
kern.cpu_currentfreq: 2000
kern.cpu_currentfreq: 2000
kern.cpu_currentfreq: 1500
kern.cpu_currentfreq: 1833
kern.cpu_currentfreq: 1500
kern.cpu_currentfreq: 1000
See that last line? So, assuming SpeedIt is accurate (to which I cannot testify, but which I strongly believe to be the case), yes, the Core Duo in my 15-inch 2 GHz MacBook Pro does indeed go as low as 1 GHz per core. Interestingly, I read (on Wikipedia?) that the frequency is regulated per core, actually, so I'm not exactly sure what SpeedIt is reporting here. It can't be an average, because values would be a lot more precise, so it's either the value of just one core (ouch!), or maybe whoever wrote that frequency is regulated per core was wrong.
Comments
Originally posted by majortom
Dunno why some XP machine idle down to 500Mhz. Maybe MacBooks are stuck to 1,5Ghz from firmware. Can you imagine how any complaints from the Mac community if a machine stucks down to 0,5Ghz (even if) in idle...?
Yeah... you have a point there... even in the Windows world... I see comments all the time about people wondering why their 3.5GHz processor is showing up as 1.5GHz. Then you have to explain the whole power management thing and what the different settings in XP actually do.
So 166 MHz (667 QDR) FSB Core Dou will turn at ~1 GHz at its lowest setting.
I would suspect that the Macs run 1.5 GHz at idle has to do more with power management driver rather than background tasks.
Originally posted by tonton
Yeah, but why doesn't it do what it can do?
It does for me.
Originally posted by skatman
There is no Pentium M/ Core Duo that is able to throttle down to 500 MHz... the lowest is 600 MHz on 100MHz (400 QDR) FSB ULV Pentium Ms.
I don't know about Core Duo, but I have seen my wife's Dell with a 1.6 GHz P-M dropping down to 32 MHz when idle on battery power. Plugging in a USB mouse however ups this to 600 MHz. In any case, the machine responds so quickly to user demand restoring the CPU speed, that the user would never notice that the CPU was clocked so low when idle without monitoring it with a dedicated utility.
By the way, how do you check in an Intel Mac the CPU speed at any time?
Originally posted by PB
By the way, how do you check in an Intel Mac the CPU speed at any time?
SpeedIt provides a sysctl interface to this.
Originally posted by tonton
Really? I think everyone else on this thread is saying that they've never seen their MacTel go below 1.5. [/B]
No, mine definitely goes down to 1.00 GHz a lot* when all I do is write / chat / etc.
*) According to MenuTemperature 1.1a2, which gets its readings from SpeedIt.
In fact, I added a little NSLog() line in it to double-check.
2006-06-21 12:06:23.665 MenuTemperature[665] 1333
2006-06-21 12:06:24.456 MenuTemperature[665] 2000
2006-06-21 12:06:25.956 MenuTemperature[665] 1000
2006-06-21 12:06:27.456 MenuTemperature[665] 1333
2006-06-21 12:06:28.956 MenuTemperature[665] 1500
2006-06-21 12:06:30.456 MenuTemperature[665] 2000
2006-06-21 12:06:31.956 MenuTemperature[665] 1333
2006-06-21 12:06:33.456 MenuTemperature[665] 1500
2006-06-21 12:06:34.960 MenuTemperature[665] 1667
2006-06-21 12:06:36.456 MenuTemperature[665] 1500
2006-06-21 12:06:37.956 MenuTemperature[665] 1333
2006-06-21 12:06:39.456 MenuTemperature[665] 1500
2006-06-21 12:06:40.956 MenuTemperature[665] 1667
2006-06-21 12:06:42.456 MenuTemperature[665] 1667
2006-06-21 12:06:43.960 MenuTemperature[665] 1833
2006-06-21 12:06:45.456 MenuTemperature[665] 1000
2006-06-21 12:06:46.956 MenuTemperature[665] 1333
As you can see, it occasionally goes down to 1000. While I don't see 1167 anywhere, every other value seems covered in this short sample.
Or, I can do the same without MenuTemperature altogether.
ataraxy:~ chucker$ while true; do sysctl kern.cpu_currentfreq; sleep 0.5; done
kern.cpu_currentfreq: 1500
kern.cpu_currentfreq: 1667
kern.cpu_currentfreq: 1500
kern.cpu_currentfreq: 2000
kern.cpu_currentfreq: 1500
kern.cpu_currentfreq: 2000
kern.cpu_currentfreq: 1833
kern.cpu_currentfreq: 1667
kern.cpu_currentfreq: 1500
kern.cpu_currentfreq: 2000
kern.cpu_currentfreq: 2000
kern.cpu_currentfreq: 2000
kern.cpu_currentfreq: 1500
kern.cpu_currentfreq: 2000
kern.cpu_currentfreq: 2000
kern.cpu_currentfreq: 1667
kern.cpu_currentfreq: 2000
kern.cpu_currentfreq: 2000
kern.cpu_currentfreq: 2000
kern.cpu_currentfreq: 1500
kern.cpu_currentfreq: 1833
kern.cpu_currentfreq: 1500
kern.cpu_currentfreq: 1000
See that last line?
Hope that helps!