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snoopy199 · Jun 8, 2006, 05:22 AM

I noticed this buried in a thread over at the apple forum and I don't think it was ever addressed.

If I run my MacBook plugged in but the battery out, the computer runs at 1.0GHz. No matter what I throw at it, the speed does not appear to change.

I normally don't use the computer this way but I am curious as to the reason or cause of this.

harrisjamieh · Jun 8, 2006, 05:28 AM

What are you using to measure the speed of the MB as 1 Ghz?

snoopy199 · Jun 8, 2006, 05:32 AM

CoreDuo Temp

Pao|o · Jun 8, 2006, 06:24 AM

battery conservation?

Simon · Jun 8, 2006, 06:51 AM

Standard behavior. Has been observed on G4 PowerBooks as well, it's not an Intel thing. Put in the battery, move on.

mduell · Jun 8, 2006, 07:03 AM

Weird... I understand running at reduced clockrates (and number of cores) when on battery to save power, but even then it clocks back up when there is enough load on the system.

Simon: Why decrease clockspeed when the battery is removed, with no way to get it back to normal speeds?

snoopy199 · Jun 8, 2006, 07:13 AM

Originally Posted by Pao|o

battery conservation?

How so? the battery is not in the machine

Pao|o · Jun 8, 2006, 10:07 AM

people dont run their notebooks without the battery, normally. i guess apple didnt program OS X to react to the way you use your mac.

snoopy199 · Jun 8, 2006, 10:29 AM

I just thought it was odd, like I said I came across this oddity over at the apple discussioin forum, I tried it out myself. I cannot imagine using my MB w/o the battery, so its of little concern for me.

I'm curious as why this occurs.

sine -''-..- · Jun 8, 2006, 11:06 AM

I think the issue is that the AC power supply would not be able to handle the peak power loads that the laptop may have - but if the battery was installed, the battery would be able to supply whatever required current.

Like - If you removed the battery, then started playing a 3d game - the video, and cpu and hard drive, screen, USB etc etc etc could be drawing more than simply the A/C adaptor could supply, and that could cause some major problems with the system.

Bennylen · Jun 8, 2006, 02:42 PM

I suspect it is a fall back saftey system. I know in a car the battery acts a filter to current spikes. If you try to jump a car off without the battery connected you can get high electrical spikes that can fry the electronics in the car. I suspect the same is true with a laptop. By having the battery in you can run full speed and not worry about spikes. WIth the battery out, there is no filter so Apple drops the speed down to hopefully avoid spikes that could harm the cpu, memory, etc.

ravinderch · Jun 8, 2006, 04:03 PM

It a bug is Mac OSx event handling with respect the message issue when the battery is removed while running on mains.

"Thermal trip indicator event is active": This forces the Mac to Slow to 1GHz to protect the CPU as it wrongly believes something evil is happening.

This feature is been used to stop heat/mooing issues.

http://discussions.apple.com/thread....hreadID=499045

1. Unplug the battery trick
Others have found that unplugging the battery causes the CPU to operate at 1Ghz, lowering the temp. However, the CPU will be stuck at 1Ghz even when you load it.

I finally found out what this does by using Apple's free developer tool Reggie SE. (Don't fool around with Reggie SE since it can kill your computer) For some reason I cannot understand, unplugging the battery trips the "Thermal trip indicator."

The exact words from Reggie SE when the battery is unpluged:
"Thermal trip indicator event is active. This indicates that the processor is above the recommended operating temperature. This bit is read-only and cleared once the temperature drops below recommended operating temperature".

Effectively, the CPU thinks that the temperature is unstable and automatically fixes your freq to 1Ghz.

So this fix is definitely a result of a bug from Apple. My best guess is that they didn't write the parameters inside the ACPI drivers to handle such an event since they don't expect users to run their MacBook minus the battery.

mduell · Jun 8, 2006, 08:00 PM

Originally Posted by sine -''-..-

I think the issue is that the AC power supply would not be able to handle the peak power loads that the laptop may have - but if the battery was installed, the battery would be able to supply whatever required current.

Like - If you removed the battery, then started playing a 3d game - the video, and cpu and hard drive, screen, USB etc etc etc could be drawing more than simply the A/C adaptor could supply, and that could cause some major problems with the system.

With an 85W power adapter, I really doubt it.

The post right above mine makes sense.

harrisjamieh · Jun 9, 2006, 01:51 AM

The MBs don't have an 85W supply, they have a 65W one. The Pro's have an 85

Pao|o · Jun 9, 2006, 02:32 AM

I was wondering why the 1.83GHz Macbook Pro was stuttering while playing Quicktime movies. No battery = poor performance

snoopy199 · Jun 9, 2006, 05:51 AM

Originally Posted by kinesin

It a bug is Mac OSx event handling with respect the message issue when the battery is removed while running on mains.

"Thermal trip indicator event is active": This forces the Mac to Slow to 1GHz to protect the CPU as it wrongly believes something evil is happening.

This feature is been used to stop heat/mooing issues.

http://discussions.apple.com/thread....hreadID=499045

This makes the most sense thanks for uncovering the most logical answer to my question

Hi I'm Ben · Jun 9, 2006, 07:13 AM

I'm not sure why you would run the computer with the battery off exposing the inside to dust and other materials. (Oh wait there's that tiny plate i'm sure that helps).

If you guys are running out of things to complain about you can surely start posting positive threads instead.

Put your battery back on, there is no logical reason for removing it.

I'm surprised I haven't seen something that says " My iSight doens't work in clamshell mode!" The title of this post is completely misleading and inaccurate. The MacBook is only running at 1Ghz because the poster chooses to use it incorrectly.

Madrag · Jun 9, 2006, 10:06 AM

Originally Posted by Hi I'm Ben

Put your battery back on, there is no logical reason for removing it.

I always assumed that leaving the battery out could preserve it (I read that when the battery is charged, the mac tops it when needed and won't wear it), but I've always left my powerbook's battery out and it seems to have preserved it - four years and still has two whole hours!

protyne · Jun 29, 2006, 04:05 AM

Originally Posted by Madrag

I always assumed that leaving the battery out could preserve it (I read that when the battery is charged, the mac tops it when needed and won't wear it), but I've always left my powerbook's battery out and it seems to have preserved it - four years and still has two whole hours!

I practice that on my Acer Wintel notebook also. 2 years on, battery good as new, during the course I did frequent cycles and use it every now and then, but never for prolong periods with A/C plugged in together with battery.

Can we call this a bug and would expect a fix? Or its designed like this and will remain like this?

HowEver · Jun 29, 2006, 06:53 PM

I tried this with an iBook 800 Mhz G4, but it didn't get the computer to run at 1 Ghz.

Not really, of course.

ghporter · Jun 29, 2006, 08:09 PM

If the battery is not in the machine, the computer won't get its status. It may think that the battery isn't charging well and thus throtles the clock to reduce power demands.

Macs with modern batteries won't hurt the battery if you leave it in and plugged in 24/7, though it's better to let it use the battery from time to time so the system will be better able to judge the charge level properly.

We've had my wife's 800MHz G4 iBook since the begining of '04, and its battery is still great, though it sits on her desk and plugged in 99% of the time.