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Shut Down or Sleep?

Shut Down or Sleep?

  • Shut Down

    Votes: 18 20.7%

  • Sleep

    Votes: 69 79.3%
  • Total voters
    87
  • Poll closed .
bellychris said:
I wonder how much power is used just starting the machine up vs. leaving it sleeping all night.
Click to expand...

-bellychris

I would too. But in the absence of the real figures, I did some quick math. Forgive me but there are a lot of assumptions here:

1. Let's assume the same amount of power is consumed during startup as any other time while awake. Granted, we know that startup is a very disk-intensive operation, and consumes a lot more than steady state, but lacking empirical evidence, let's go Occam's Razor.

2. One can get 15 days out of sleep from full charge

3. Machine is MacBook Pro Core 2 Duo with 85w/hr power requirements.

4. MBP will last 3 hours full power on battery (yes, that's generous, but I'm being conservative here)

Ok, here's what I did, I needed to reconcile the fact that the MBP would last 3 hours on Battery awake, but 15 days asleep. I needed to calculate the watthours of both states. Well, the fully awake is 3*85watthours - easy enough. How much of that watthours are consumed by startup? Say a minute. That's 0.0093% total capacity (1min divided by 10800tot min powered (3hrs)).

Ok, then I calculated the total time-to-discharge of the battery asleep over 15 days, or 1296000 minutes, and divided that against the 0.0093% capacity consumed by 1 minute of full consumption. This yields that 1 minute of full power = 120 minutes of sleep.

Again, this is really quick and dirty - but I think the logic holds - and I overcompensated for the assumptions to the point where I think the 120minSleep=1minAwake is actually higher.
 
patrick0brien said:
-bellychris

I would too. But in the absence of the real figures, I did some quick math. Forgive me but there are a lot of assumptions here:

1. Let's assume the same amount of power is consumed during startup as any other time while awake. Granted, we know that startup is a very disk-intensive operation, and consumes a lot more than steady state, but lacking empirical evidence, let's go Occam's Razor.

2. One can get 15 days out of sleep from full charge

3. Machine is MacBook Pro Core 2 Duo with 85w/hr power requirements.

4. MBP will last 3 hours full power on battery (yes, that's generous, but I'm being conservative here)

Ok, here's what I did, I needed to reconcile the fact that the MBP would last 3 hours on Battery awake, but 15 days asleep. I needed to calculate the watthours of both states. Well, the fully awake is 3*85watthours - easy enough. How much of that watthours are consumed by startup? Say a minute. That's 0.0093% total capacity (1min divided by 10800tot min powered (3hrs)).

Ok, then I calculated the total time-to-discharge of the battery asleep over 15 days, or 1296000 minutes, and divided that against the 0.0093% capacity consumed by 1 minute of full consumption. This yields that 1 minute of full power = 120 minutes of sleep.

Again, this is really quick and dirty - but I think the logic holds - and I overcompensated for the assumptions to the point where I think the 120minSleep=1minAwake is actually higher.
Click to expand...

good info, and also that initial startup, you know immediately after you press the power button, must also consume alot more power per hour then just the computer running in its normal state.
 
I sleep my MacBook Pro whenever I'm not using it, it's so convenient to have everything waiting for me just as I left it.

I don't shut down or sleep my Mac Pro. Ever. I have it running 24/7 but the monitors sleep after 15 minutes inactivity
 
a good way around the power problem (for portables) have your computer sleep at night...unplugged. then when it wakes up, put the plug back in. it only drains my battery about 2% usually.

S
 
bellychris said:
good info, and also that initial startup, you know immediately after you press the power button, must also consume alot more power per hour then just the computer running in its normal state.
Click to expand...

-bellychris

Yeah, sorry - I was trying to say that in Assumption 1, I'm sorry I wasn't more clear.

Without knowing the precise consumption on powerup, I used the average watthour. Adding to your point, I think the only single-user operation that would consume more power than startup, would be performing an SMP floating point render.
 
I've never slept or shut down my computers at night, since, oh I dunno, 1998 or something? I want my online services running all the time, and fortunately my PowerBook and Mac Pro have both been quiet enough that I can do that without disturbing my sleep. I turn off my monitor and wireless input devices of course, but the computer hums merrily all night, serving up files and keeping messages from AIM buddies until I wake up in the morning.
 
macOSX-tastic said:
a good way around the power problem (for portables) hav your computer sleep at night...unplugged. then when it wakes up, put the plug back in. it only drains my batter about 2% usually.

S
Click to expand...

Oh, how does it work for Tower's/Desktops. I thought OS X didn't sleep like XP where you can kill the power and it'll continue from sleep. I was told with OS X if you kill the power in sleep and switch it on again it'll do a full boot...?
 
balamw said:
Hibernating is called "Safe Sleep" on Macs, and all recent battery equipped Macs support it out of the box. (i.e. not an iMac).

http://andrewescobar.com/archive/2005/11/11/how-to-safe-sleep-your-mac/

B
Click to expand...

I have enabled Safe Sleep on my iMac and it worked perfectly,

I was testing an applescript app i wrote for my house-mate who wanted to be able to easily switch between Safe Sleep and normal sleep on his Macbook. i.e. the walk into Uni (30 minutes) Safe Sleep while in Uni Sleep, the walk back (40 minutes, uphill) Safe Sleep.
 
balamw said:
I presume that doesn't apply if you unplug the iMac or have a power failure, right?

B
Click to expand...

I thought that was the point of safe sleep, i will enable it again and try it out, however my iTunes library is currently down sampling for my nano so won't be able to try at least for another 2 hours approximately and i will be going to bed shortly so i will report back tomorrow.
 
MacNut said:
So do you unplug the fridge too when not in use.:rolleyes:

A computer in sleep mode is drawing maybe 10 watts, it is hardly enough to be hurting anything.
Click to expand...

A fridge is meant to be running all the time. Do you put your frozen meat in your Mac?

Every little bit of power used counts. Think how many Mac/PC users are out there. So what do you get when you multiply 10 watts by let's say 1 million?

Even power adapters that are not being used (think of phone charger, or any type of power adapter with a transformer) add load to the grid. They each use very little power, but when you multiply a very little number with millions you get a pretty significant number.

Anyhow, I powerdown my Mac when it will not be used for several hours.
 
YunusEmre said:
A fridge is meant to be running all the time. Do you put your frozen meat in your Mac?

Every little bit of power used counts. Think how many Mac/PC users are out there. So what do you get when you multiply 10 watts by let's say 1 million?

Even power adapters that are not being used (think of phone charger, or any type of power adapter with a transformer) add load to the grid. They each use very little power, but when you multiply a very little number with millions you get a pretty significant number.

Anyhow, I powerdown my Mac when it will not be used for several hours.
Click to expand...

You should read this. Less than 1W when the MBP is in sleep mode. And just because it uses an 85W adapter, doesn't mean it's using 85W all the time.
I agree with those that say frequent startups use more power than if you had it in sleep the entire time. Here's what happens at startup (among other things): Hard drives spin up and get accessed heavily reading the essential OS things needed to complete the booting, the CPU has to process all the stuff it has to process (what a great explanation :rolleyes: ), and 20 seconds or so later, it's all done.
Here's what uses power during sleep: the RAM, the sleep LED, USB ports (so input devices can wake the computer), and I suppose a bit to the CPU. The hard drive is spun down and the heads are parked both for power reasons and in case of a drop.
 
as far as the laptop being warm during transfer, make sure you don't allow your mac to wake from various external devices or bluetooth cause that might do the trick as well.
as far as the ecology claim goes, i'm still with the sleep mode.
the point is clear.
if you shut down and start up your computer twice a day (or maybe even once?) that consumes more power than having it sleep all night,
hence less power consumption.
also, to be more blunt, the minute the u.s. signs the kyoto treaty and starts making proper efforts to not polute the earth more than the rest of the planet, i will personally go live in a hut in the mountains and eat grass, just to minimize my detrimental effect on the environment.
i believe we have more important things to worry about when it comes to power consumption, and since sleep consumes less power, then there's no need to talk about this any more, innit?
in the end, the point is clear, people prefer sleep to shutting down.
i'd suggest shutting down when you're gonna transfer your mac though, just to be on the safe side :D
 
patrick0brien said:
-bellychris

Ok, here's what I did, I needed to reconcile the fact that the MBP would last 3 hours on Battery awake, but 15 days asleep. I needed to calculate the watthours of both states. Well, the fully awake is 3*85watthours - easy enough. How much of that watthours are consumed by startup? Say a minute. That's 0.0093% total capacity (1min divided by 10800tot min powered (3hrs)).

Ok, then I calculated the total time-to-discharge of the battery asleep over 15 days, or 1296000 minutes, and divided that against the 0.0093% capacity consumed by 1 minute of full consumption. This yields that 1 minute of full power = 120 minutes of sleep.
Click to expand...


Um... should I quibble about the fact that 3 hrs = 180 min and not 10800. Also 15 days = 21600 minutes and not 1296000.

You did all the calculations for seconds and ended up with the correct result anyways, having made the same mistake twice. So yes 1 second of full power ~= 120 seconds of sleep and the ratio holds for minutes and hours as well.

And just to add my voice here.. I use sleep mode almost exclusively and rarely shutdown. I think given that sleep and wake will use less energy than a shutdown/restart, its wrongheaded to shutdown unless you are gone away for a long time.
 
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