[OSX-Users] Re: RAM for a macbook

[Steve Harris]

I think for some time they've written the state to disk, as well as RAM, just incase it runs out of power completely.

An earlier laptop I had drained the battery fairly fast when asleep, so sometimes I'd let is go all the way to sleep, remove the battery, put it back and and then board the plane/whatever.

When it woke up it would have to unsuspend from disk, which takes bloody ages, but at least you'd have some power left.

With more recent machines, I don't see the need though. Power drain while sleeping seems to be very low.

- Steve

On 2010-08-23, at 12:58, Christopher Gutteridge wrote:

> Sometimes when I need to preserve the battery I use
> 
> % pmset -a hibernatemode 1
> 
> which sets it to actually write the memory to disk when it goes to sleep. You get the annoying wait for it to start up again (20-30 seconds) but it's great if you want to preserve the current desktop setup without draining the battery. You can restore it to the normal mode with
> 
> % pmset -a hibernatemode 3
> 
> and view the current setting with
> 
> % pmset -g
> 
> I don't know how to set this option via the GUI.
> 
> On 23/08/10 10:51, Steve Harris wrote:
>> On 2010-08-23, at 03:08, Hugh Glaser wrote:
>> 
>>   
>>> I hesitate to venture into such informed company, and not wholly agree with
>>> a tiny bit of it, but... :-)
>>> 
>>> On 19/07/2010 18:13, "Steve Harris"<swh at ecs.soton.ac.uk>  wrote:
>>> 
>>>     
>>>> On 2010-07-19, at 17:44, Marcus Cobden wrote:
>>>>       
>>>>> On 19 Jul 2010, at 17:33, Christopher Gutteridge wrote:
>>>>> 
>>>>>         
>>>>>> My macbook (White, 2Ghz) is feeling a bit slow and I think it would benefit
>>>>>> from an increase in RAM. (currently 1GB)
>>>>>> 
>>>>>> How much can I upgrade it to?
>>>>>>           
>>>>> Depends on the model:
>>>>> https://secure.wikimedia.org/wikipedia/en/wiki/Macbook#Model_specifications
>>>>> 
>>>>>         
>>>>>> Is it worth it?
>>>>>>           
>>>>> Yes.
>>>>> 
>>>>> I may have imagined it, but I got the feeling that my battery lasted a little
>>>>> less longer with more RAM. I have no idea if this differs between brands of
>>>>> RAM though.
>>>>>         
>>>> That's normal, it's because the disk is doing less work.
>>>>       
>>> Only so far.
>>> If you can afford shitloads of RAM, then the battery will spend its time
>>> powering the extra RAM that is not being used.
>>> Probably not a problem.
>>> But the battery life when asleep may be reduced, as it is keeping the RAM
>>> alive.
>>>     
>> That's probably true, yes. Current generation machines seem to be very efficient when asleep though. I didn't notice any difference on my macbook pros going 2->4, but I wasn't looking out for it. I did notice the difference in runtime though.
>> 
>>   
>>> Mind you, this was a few years ago, and I am sure that someone will tell me
>>> that it is no longer true.
>>> 
>>> But a 1->2 upgrade is likely to be stunning.
>>>     
>> Also a 2->4 upgrade is well worth it, in my experience.
>> 
>>   
>>> It is possible that maybe 0.75 Gig of the memory is used most of the time
>>> (system, etc.), and so you will then get 5 times that memory for the other
>>> stuff.
>>> And if you can get to 4 Gig (I wrote Meg first time, as I still remember
>>> machines with K!), then the machine will be better and is likely to last
>>> longer without additional cost or upgrade hassle.
>>> 
>>> One of the things that has changed over the last few years is how long
>>> machines last. Used to be a couple of years, but a machine like yours, that
>>> was bought a year or two (or more?) ago, will still be good for maybe 3 or 4
>>> more years, unless you are doing fancy graphics processing (or similar) on
>>> it.
>>> 
>>> Laptops tend to be hard to upgrade bits of memory, so put the most you can
>>> afford in now.
>>>     
>> That seem to vary a lot, the difficulty of upgrading RAM in last 3 Mac laptops I've had were: trivial (no screwdriver needed), almost impossible, small amount of screwdriver work needed - in chronological order.
>> 
>> - Steve
>>   
> 
> -- 
> Christopher Gutteridge -- http://id.ecs.soton.ac.uk/person/1248
> 
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> / Web Projects Manager, ECS, University of Southampton, http://www.ecs.soton.ac.uk/
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>