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how well does it keep the time?

M

magicMac

macrumors 65816
Original poster
Apr 13, 2010
1,014
431
UK
How well does the watch keep track of time when disconnected from iPhone/Internet/NTP? Does the watch use a real-time operating system and/or a fixed clock-rate processor?


I was wondering how seriously apple have taken the apple watch as a watch. Apple have worked on real-time operating systems before, such as in the airport line-up which uses a flavor of the OS used in the mars rover curiosity, and it would make a lot of sense in the watch.
 
magicMac said:
How well does the watch keep track of time when disconnected from iPhone/Internet/NTP? Does the watch use a real-time operating system and/or a fixed clock-rate processor?


I was wondering how seriously apple have taken the apple watch as a watch. Apple have worked on real-time operating systems before, such as in the airport line-up which uses a flavor of the OS used in the mars rover curiosity, and it would make a lot of sense in the watch.
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Is this a joke? I assume it keeps time about as well as a $5 casio (i.e., nearly perfectly). And then it corrects itself when it again has access to the internet through the phone.
 
I reckon if it was away from the iPhone for over six months, it may become slightly inaccurate. If it is connected everyday, it will stay accurate.
 
Both keynotes made a big deal about how accurate the watch is at keeping time. And it'll undoubtedly sync itself periodically when it can. I suspect time accuracy is the last thing anyone would need to be concerned about.
 
On Apple's website they say that the timekeeping capabilities are so accurate that all the Apple Watches in the world will have their seconds-hand in sync with eachother. And for those that choose the Micky Mouse face, he's foot will tap in sync with all the mouse feet around the world. This sounds like an amazing feat, but I've checked, and my iPhone 6 Plus and iPad Air 2 both have their seconds-hands in the clock icon in sync with each other, so obviously Apple has been capable of doing this for some "time" :D

Whether the internal chronometer can maintain that precision indefinitely, or it requires periodic synchronization though the Internet or the GPS signal, we may never know, but I suspect the latter.
 
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I think the time is probably only that accurate when in synch with an iPhone that can update its time from time servers on the Internet. I highly doubt its a super accurate watch by itself. But I'm sure its accurate enough.
 
There's no need for an RTOS to maintain accurate time, just a real hardware clock and a properly prioritized scheduler in the kernel. Maintaining very accurate time is not difficult in modern tech. Apple claims to maintain accuracy with 50ms. In computer terms, that's an enormous amount of variance and will be easily achieved.
 
Look, if you are buying a $500-$17000 smart watch to NOT connect to an iphone, then maybe you should be looking elsewhere for Olympic quality accuracy. But if you go for a run without your phone, you won't notice any difference in timekeeping. Apple said the thing checks the atomic clock 4 times an hour or something, so it appears to be highly accurate if you let it talk to your phone on a regular basis.
 
I think people have officially run out of questions to ask about the apple watch.
 
kovey said:
I think people have officially run out of questions to ask about the apple watch.
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The rather anal retentive question in the OP has been asked right after the Watch was unveiled 6 or so months ago, but it seems like a silly question to me because you'll be pairing it with your iPhone most of the time anyway.
 
magicMac said:
How well does the watch keep track of time when disconnected from iPhone/Internet/NTP? Does the watch use a real-time operating system and/or a fixed clock-rate processor?
Click to expand...

I heard from someone that S1 was designed specifically to resist clock drift, so even if Apple Watch has not connected to WiFi or iPhone for awhile, the clock will stay accurate. Also, real time clock in most modern CPUs are accurate within 200 milliseconds, even with periodic poll to NTP server. So Apple must have done something special to stay accurate within 50 milliseconds.
 
JayLenochiniMac said:
The rather anal retentive question in the OP has been asked right after the Watch was unveiled 6 or so months ago, but it seems like a silly question to me because you'll be pairing it with your iPhone most of the time anyway.
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Asking how well a watch can keep the time is anal retentive ? Wow, just wow.

Anyway, the idea of the question was literally to discuss it, out of curiosity, this is a forum after all. And as we all know, apple goes into great detail sometimes, whether it really matters or not.

Besides, you just know someone is going to leave an apple watch in a draw for 6 months and then let the whole world know how inaccurate the apple watch is and make headlines. Bad news sells, especially when apple is involved.
 
magicMac said:
Asking how well a watch can keep the time is anal retentive ? Wow, just wow.

Anyway, the idea of the question was literally to discuss it, out of curiosity, this is a forum after all. And as we all know, apple goes into great detail sometimes, whether it really matters or not.

Besides, you just know someone is going to leave an apple watch in a draw for 6 months and then let the whole world know how inaccurate the apple watch is and make headlines. Bad news sells, especially when apple is involved.
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It's retentive in the fact that, as has been stated, even a $5 Casio loses at most 2 seconds per year...
So, in essence, you're worried about losing one second of accuracy if your phone is disconnected for six months straight. Does that NOT seem anal to you??
 
nutmac said:
I heard from someone that S1 was designed specifically to resist clock drift, so even if Apple Watch has not connected to WiFi or iPhone for awhile, the clock will stay accurate. Also, real time clock in most modern CPUs are accurate within 200 milliseconds, even with periodic poll to NTP server. So Apple must have done something special to stay accurate within 50 milliseconds.
Click to expand...

My thoughts exactly. Probably, the S1 will have an oscillator which is calibrated to almost exactly one second and is separate from the main CPU which is designed to take a series of instructions and execute them as fast as possible.

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Tycho24 said:
It's retentive in the fact that, as has been stated, even a $5 Casio loses at most 2 seconds per year...
So, in essence, you're worried about losing one second of accuracy if your phone is disconnected for six months straight. Does that NOT seem anal to you??
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Who said I'm worried about it? my phone will be connected to the watch most of the time. As has been stated, I was curious and the answer is +/- 50ms. And by the way a £5 Casio watch doesn't work anything like a microprocessor.

And trust me, it could be a good few seconds out in 6 months, many people don't notice how inaccurate their analogue watches are because they wind them back and forth each year for daylight savings.
 
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JayLenochiniMac said:
You're going to be pairing it with the iPhone the vast majority of the time. Being preoccupied about how well the Watch keeps the time for the 1-2 hours you work out (without the iPhone) is indeed anal retentive.
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The amount of negativity, borderline profanities, personal insults and simply off-topic responses on these forums is beyond comprehension sometimes.
 
The electronic oscillations will probably put the Apple Watch into the certified chronometer range which would be accurate within that 50 milliseconds. Certified chronometers are accurate within 20 milliseconds. Modern quartz based watches can lose or gain time anywhere between 20 milliseconds to 2 seconds per day. To give you an idea of how accurate that is, mechanical watches can lose or gain time anywhere between 1 minute and 4 seconds. The most accurate timekeeping devices are atomic clocks which are now accurate within 1 second over the course of 300 million years. I believe that Apple has time sync to those atomic clocks so if you are connected to an iPhone, the Apple Watch should keep close to perfect time (as perfect as possible). If you're off of the iPhone, we will probably still be within that 50 milliseconds per day.
 
magicMac said:
My thoughts exactly. Probably, the S1 will have an oscillator which is calibrated to almost exactly one second and is separate from the main CPU which is designed to take a series of instructions and execute them as fast as possible.

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Who said I'm worried about it? my phone will be connected to the watch most of the time. As has been stated, I was curious and the answer is +/- 50ms. And by the way a £5 Casio watch doesn't work anything like a microprocessor.

And trust me, it could be a good few seconds out in 6 months, many people don't notice how inaccurate their analogue watches are because they wind them back and forth each year for daylight savings.
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Nope.
You're simply wrong.

http://gizmodo.com/5983427/why-a-10-casio-keeps-better-time-than-a-10000-rolex
 
magicMac said:
Besides, you just know someone is going to leave an apple watch in a draw for 6 months and then let the whole world know how inaccurate the apple watch is and make headlines. Bad news sells, especially when apple is involved.
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The idea that someone is going to pull an Apple Watch out of a drawer, after not caring about it for six months, and immediately compare it to another device that is 100% accurate, then recognize that it's about half a second off... flip into a rage & post on the internet... & that his ludicrous ire would make headlines is the height of delusional absurdity.

Please.
Stop.

Your point has been handily refuted. Know when to quit.
 
You clearly haven't been following the next *place_madeup_problem_here*gate thread !

What is it I need to quit ? Having curiosity ? Questioning theories ?

I sure do hope you don't work in the field of science. I think you just like being the centre of attention by provoking argument. There have been plenty of interesting and funny replies one this thread which have now got buried in between.
 
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Tycho24 said:
The idea that someone is going to pull an Apple Watch out of a drawer, after not caring about it for six months, and immediately compare it to another device that is 100% accurate, then recognize that it's about half a second off... flip into a rage & post on the internet... & that his ludicrous ire would make headlines is the height of delusional absurdity.

Please.
Stop.

Your point has been handily refuted. Know when to quit.
Click to expand...
The well known publication Astronomy Today, has reported that the often discussed Steve Jobs Reality Distortion Field is still present in the atmosphere. Perhaps the OP has read up on this phenomenon and is extrapolating accordingly.
 
magicMac said:
Yes a cheap Casio does keep time well. That was my point... (A Rolex does not have a microprocessor incase you need that clarifying)

So I'm not entirely sure who is wrong about what.
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Well, it breaks down like this...

YOU are wrong in saying that any modern electronic watch would lose more than a few seconds a year.
YOU are wrong that there is any worry about Apple Watch being off by any recognizable amount at all after being disconnected from the phone for a few months.
And I.... well, luckily- I don't think I've been wrong about anything so far in this conversation! :)
 
Tycho24 said:
Well, it breaks down like this...

YOU are wrong in saying that any modern electronic watch would lose more than a few seconds a year.
YOU are wrong that there is any worry about Apple Watch being off by any recognizable amount at all after being disconnected from the phone for a few months.
And I.... well, luckily- I don't think I've been wrong about anything so far in this conversation! :)
Click to expand...

Well since I never said either of them things I can't be wrong about them! Feel free to rate yourself though :)
 
magicMac said:
Well since I never said either of them things I can't be wrong about them! Feel free to rate yourself though :)
Click to expand...

Hmmmmm.....
Decisions, decisions....
Quote you saying the things you claim you didn't say, but you really did.... like moments ago. Or realize you are like a dog chasing your own tail & just add you to my ignore list??

Aww... what the heck?? I'm gonna do both!! =)

magicMac said:
And trust me, it could be a good few seconds out in 6 months, many people don't notice how inaccurate their analogue watches are because they wind them back and forth each year for daylight savings.
Click to expand...

magicMac said:
Besides, you just know someone is going to leave an apple watch in a draw for 6 months and then let the whole world know how inaccurate the apple watch is and make headlines. Bad news sells, especially when apple is involved.
Click to expand...

Must've been your evil doppelgänger that posted those posts that you didn't post & said those things that you didn't say!!!!
Toodles! Talk to you never.

*block*
 
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