MacBooks Run Slow Without Battery
A new "Power Saving Feature" in the unibody MacBook and MacBook Pros was inadvertently discovered by Gearlog while they were doing a routine benchmark.
Gearlog was benchmarking was to test third party RAM modules for use in the new MacBook Pros, but discovered that the notebook’s processing power significantly decreased after the battery was removed during the test. It was confirmed that Apple does indeed scale back the CPU processing speed while operating on AC power without a battery installed.
According to this support document, Apple essentially down-clocks the CPU to prevent the system from shutting down if it happens to demand greater power than the AC adapter alone can provide: "If the battery is removed from a MacBook or MacBook Pro, the computer will automatically reduce the processor speed. This prevents the computer from shutting down if it demands more power than the A/C adapter alone can provide."
Collaboration from other users can be seen on the Gearlog comments; however, since this support document was last updated in August 2008, I decided to do some independent testing on my own MacBook Pro. I wanted to see if this problem existed in late model MacBook Pros or were they limited to only the new unibody MacBook Pros. Using the same Cinebench R10 benchmarking software, I conducted the full tests three times each with the WiFi and Bluetooth radio disabled and carrying forward the best scores achieved each time.
Gearlog’s own results show a decrease of 36 percent in processor speeds without a battery attached on their unibody MacBook Pro. Our own tests show a decrease of 50 percent when rendering with one CPU, a decrease of 52 percent in multiprocessor rendering, while the GPU suffered a 40 percent decrease in performance.
What does Apple have to say about this? The official statement from its support document is that “It is strongly recommended that you do not use your MacBook or MacBook Pro while the battery is removed.”
The only benefit in operating a notebook without its battery is to conserve charge cycles and thereby extending the battery life. Apple recommends that with notebook batteries, occasional power flow is necessary for its longevity. Standard maintenance is not to constantly keep the battery charged but rather allow it to discharge partially before recharging it again. If your use is infrequent, it is recommended that the battery be completely discharged and recharged once per month.
With such drastic performance decreases on a previous generation Macbook Pro, it doesn’t seem logical to remove the battery when a brand new battery can be purchased for $129 from Apple or possibly even less from other resellers. I would rather have a full powered notebook and a few months less with my battery than the alternative.
Another bull-shit explenation.
Li-ion batteries need no discharge, and complete discharge is what destroys them fastest!
I suggest the person talking about batteries knows not of what he talks.
Otherwise, strange to see that an apple would do the clockdown.
It can be prevented by having (or investing) in a more powerfull adaptor!
I guess that's the cost of saving huh?
A laptop AC adapter must provide more than enough power to run (and here's the important part) *and* charge the battery simultaneously. This always leaves enough headroom to ensure there's enough power.
I reject Apple's notion that a MacBook Pro without a battery will draw more power than the AC adapter it shipped with.
In some *strange* case where a user has a 3rd party AC adapter, this might be helpful; and if a Mac user called Apple to complain about it, the first thing Apple Tech Support will say is "Do you have an Apple-supplied AC Adapter?" "No?" "We cannot support your configuration, let me direct you to sales so you can buy an apple-certified part."
Any questions?
The macbooks should not even need that much power.
I'm guessing apple decided to make a lower powered adapter in order to increase profits while cheating the consumer. Its a shame, dell, toshiba, Hp and the rest making good adpators that charge ure laptop's battery while plugged in and do it pretty darn quickly (even if ure using your pc at the time).
They (however) do get very hot in the process so i'm guessing the components used in them are cheap as well. Either way, i'd rather have a laptop running at full power with or without the battery rather than castrated performance cause the battery was missing when i decided to use my laptop. Crazy stuff!
also on the part, we know that a complete discharge will destroy a lithium ion battery faster, i think its also the same with NiMH.
the only advantage of a complete discharge is avoidance of memory effect which is not present in lithium ion batteries.
i could have believed one comment here that it forces depreciation faster but i DON'T think an old battery will force the macbook slower.
one thing good though with having a battery always on the notebook is avoiding loss of data during power failures.
The point of this article is not that Apple notebooks are constantly sucking on the battery even when plugged in. It is that occasionally when your 2.8Ghz processor, 15" screen (brightness cranked), 9600 GT, and 7200RPM HDD (the Macbook Pro's top configuration) are all running at max capacity, you may need to use a bit of the batteries power, and Apple has taken steps to ensure your system doesn't shut down. What other notebook fits that kind of capacity into an 85W envelope anyway? Most others, comparably configured, would ship with a bulky-as-hell 120W which, believe you me, is not something you want to travel with, a fact which entirely eliminates the advantage of the Macbook Pro's design.
Yes, Apple could have designed the functionality better. Spikes in power demand are certainly hard to detect in time to prevent a shutdown, but not so hard that this functionality should be turned on all the time, regardless of load. However...
While a lot of you may not like Apple, that shouldn't spur you to stretch every bit of negative press into a conspiracy based on ignorance.
"Hey sweet I gonna play (insert 3D game here)."
"Oh damn I left my Macbook in standby and only have 25% battery. I guess that means I can only play (3D game) for 30 minutes or so before my battery runs out and my Macbook goes into cripple mode."
"Guess I shouldn't have gotten that 9600 GT, or maybe that 2.8 Ghz processor, or it could be that 7200 RPM hard drive draining my battery."
"Actually I guess I shouldn't have bought a Macbook, because it is incapable of sustained full load use and charging itself.
On normal conditions this should not be an issue, since most programs only require a small cpu or GPU loadtime,and the majority of the time the processor is running at low speed,saving power which can be directed to charging the battery.
Apple's computers aren't really made for gaming anyways, but that they advise to run a Li-ion battery totally empty I find weird.
It is so, that a Li-ion battery can be destroyed (can never reach the voltage needed to start charging) when being completely empty.
why do people continue to buy this overpriced junk??
the adapter gives enough power
my friend has a mac book pro and when running a 3d modeler, he left the PC rendering for over a week
if the adapter didn't give enough power, then the battery would have dies within hours
Or it just clocked back when the battery got too low.
nope, he uses the laptop a lot while rendering as his college courses require him to do a lot of work
the battery stays fully charged all the time no matter what the cpu load
he runs maya 3d and to get better results, I thought him how to make more realistic metal by combining the DGS material (not commonly recommended especially by professors as it is nearly impossible to do animation using a single pc), with the dielectric material to allow a shiny metal look with a nice detailed gloss look
the problem with this is that it can turn a 4 hour mental ray render task, into a 4-5 day render task