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Old 2012-09-13, 18:19   #1
JuanTutors
 
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Default Feature request

I'm realizing my processor is actually powerful enough so that, while running prime95, it cannot charge in an appreciable amount of time. I use my laptop for projection as well as normal use.

So my request is, create an option that says "Do not run Prime95 when computer battery is below 50%", or something along those lines.
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Old 2012-09-14, 04:05   #2
LaurV
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Short answer:
There is already such an option in menu Options/Prefrrences, you have a check box saying "run when on battery power". Just take it off (uncheck it).

"TL;DR" version:
Unless you have a very expensive battery which holds your laptop on full CPU throttle for many hours (like those used for helicopters, of for nissan leaf or toyota prius cars, think about something about 8 to 50 times more expensive than whole your laptop, which can supply it in full for 20-50 hours or so), it makes no sense to think about running P95 on the first 50% of the battery. Physically, the battery goes down exponentially. If your battery can power your laptop for few hours, say 3 hours, when you work in winword, powerpoint, presenter, whatever, then reaching 50% of battery happens somewhere at say 2 hours point. Using P95 it will short the time to one hour, or even less, 40 minutes (until the computer dies because of no battery, or battery under the set limit). So, in fact, if you run P95 until the battery is 50%, then use the computer "normally" until it dies because of no battery, you will be able to run P95 for about 20 minutes, and then you still can use the computer "normally" for one more hour, or less. Does it make any sense? What is your benefit from it, beside of... shortening your battery life? (you will need to change it after 2 years or less! because of the high stress caused by fast discharging)

My advice is: use the computer for p95 crunching only when it is powered on by the wall socket (plugged in). If possible, try to avoid getting it hot (like using "Throttle=" parameter, see undoc.txt, clean it periodically to remove the dust clogs from the fans, etc.), and if it however gets somehow hot, then take the battery out completely during this time!

This is no joke, look on wikipedia for lithium-ion batteries, their life time shorten a lot if they get heated up). I do this for a ten-years-old laptop which is used as router in my house and is mostly (99% of the time) plugged in - i took off the battery (if there is no electricity anyhow I have no internet signal because the other things are powered from the same source) and is doing some P-1 stuff too. The battery is used occasionally, if I need the laptop portable, or when I plug it periodically for charging, like every 6-8 weeks or so. As a result, that batter is still "like new" after about 7-8 years. The original battery died after the first 2-3 years (during that time the battery was inside always, the laptop was plugged in most of the time, at the office at home, and unplugged only during transportation, and of course it was continuously running P95, getting quite hot). For the other laptop which I still use for about 7 years, I have changed 2 batteries already, now I am at the third. The work I do can't stand power failures, so I can't take the battery out. My daughter and my wife laptops are 3 respective 2 years old, and they started having problems with the batteries, diminished capacity, decreasing the "work on battery" time to about half. Of course, both are getting somehow hot when plugged in, from obvious reasons of distributed computing and me being lazy to clean them more often and the battery is never taken out. Try convince my lass that she has to take the battery out when she is on facebook, and see how many scratches you can count on your face after that.

I have posted things in the past about damaged batteries and bended fans in laptops because of heat. Some people say is not possible, well, your mileage may vary, your money, your fun.

Last fiddled with by LaurV on 2012-09-14 at 04:22
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Old 2012-09-14, 04:14   #3
Dubslow
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Quote:
Originally Posted by LaurV View Post
My advice is: use the computer for p95 crunching only when it is powered on by the wall socket (plugged in).
Umm... I think you misunderstand him. He said that even when his laptop is plugged in, Prime95 causes the power draw to go so far up that he can't charge the batteries.
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Old 2012-09-14, 04:16   #4
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Quote:
Originally Posted by LaurV View Post
Short answer:
There is already such an option in menu Options/Prefrrences, you have a check box saying "run when on battery power". Just take it off (uncheck it).

"TL;DR" version:
Unless you have a very expensive battery which holds your laptop on full CPU throttle for many hours (like those used for helicopters, of for nissan leaf or toyota prius cars, think about something about 8 to 50 times more expensive than whole your laptop, which can supply it in full for 20-50 hours or so), it makes no sense to think about running P95 on the first 50% of the battery. Physically, the battery goes down exponentially. If your battery can power your laptop for few hours, say 3 hours, when you work in winword, powerpoint, presenter, whatever, then reaching 50% of battery happens somewhere at say 2 hours point. Using P95 it will short the time to one hour, or even less, 40 minutes (until the computer dies because of no battery, or battery under the set limit). So, in fact, if you run P95 until the battery is 50%, then use the computer "normally" until it dies because of no battery, you will be able to run P95 for about 20 minutes, and then you still can use the computer "normally" for one more hour, or less. Does it make any sense? What is your benefit from it, beside of... shortening your battery life? (you will need to change it after 2 years or less! because of the high stress caused by fast discharging)

My advice is: use the computer for p95 crunching only when it is powered on by the wall socket (plugged in). If possible, try to avoid getting it hot (like using "Throttle=" parameter, see undoc.txt, clean it periodically to remove the dust clogs from the fans, etc.), and if it however gets somehow hot, then take the battery out completely during this time!

This is no joke, look on wikipedia for lithium-ion batteries, their life time shorten a lot if they get heated up). I do this for a laptop which is used as router in my house and is mostly (99% of the time) plugged in (if there is no electricity anyhow I have no internet signal because the other things are powered from the same source) and is doing some P-1 stuff too.

I have posted things in the past about damaged batteries and bended fans in laptops because of heat. Some people say is not possible, well, your mileage may vary, your money, your fun.
I think you've misunderstood. I don't run Prime95 on battery power. I run it only plugged in. I have that setting set.

I mean, if I leave my laptop plugged in starting from a low battery point (say 14%) then to get to 100%, the charging process does not produce charge fast enough to charge it in an entire school day.

My suggestion is: Add an option so that when plugged in, prime95 doesn't run unless the battery charge is high enough. That would allow people like me who run their laptops hard to be able to charge fast enough.
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Old 2012-09-14, 04:28   #5
LaurV
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Oh! Sorry for misunderstanding. To solve your problem use Throttle. You can find a very good compromise between the charging time and working time, and this will also protect your laptop (less heat) and battery.

For example, try doing some experiments and see how long you battery need to charge to 50%, how long your computer is plugged in, how long it works on battery. Then set the throttle in such a way than you do the same amount of work per 24 hours as you would do if "stop p95, charge battery, start p95 at 100% throttle".
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Old 2012-09-14, 04:44   #6
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Quote:
Originally Posted by LaurV View Post
Oh! Sorry for misunderstanding. To solve your problem use Throttle. You can find a very good compromise between the charging time and working time, and this will also protect your laptop (less heat) and battery.

For example, try doing some experiments and see how long you battery need to charge to 50%, how long your computer is plugged in, how long it works on battery. Then set the throttle in such a way than you do the same amount of work per 24 hours as you would do if "stop p95, charge battery, start p95 at 100% throttle".
Perhaps, it is just simpler to just run fewer workers? I mean, with all the throttling and everything, the aggregate thruput might not be all that different.
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Old 2012-09-16, 19:22   #7
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Default Yes, run one less thread to save power!

You can monitor CPU power draw on some cpus using CoreTemp (and others). On an I5 2500k at stock speed, running all four threads, P95 forces the cpu to draw 57 watts. Reduction of just one worker thread reduces draw to 50 watts.
Reduction of two threads reduced draw to 38 watts.

http://www.alcpu.com/CoreTemp/
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Old 2012-09-16, 23:07   #8
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Quote:
Originally Posted by swl551 View Post
You can monitor CPU power draw on some cpus using CoreTemp (and others). On an I5 2500k at stock speed, running all four threads, P95 forces the cpu to draw 57 watts. Reduction of just one worker thread reduces draw to 50 watts.
Reduction of two threads reduced draw to 38 watts.

http://www.alcpu.com/CoreTemp/
Really?
I thought you couldn't measure power consumption internally?
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Old 2012-09-16, 23:28   #9
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Default You can measure CPU wattage on Sandy Bridge.

No knowledge of any other platforms but for sure on Sandy Bridge
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Old 2012-09-17, 01:18   #10
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Those options produce some of the desired effects but with significant drawbacks. Cutting a worker thread reduces the throughput by 25% (presumably). Throttling, no matter what calculations I do to take into account 24 hours or even just an entire school day, will still keep my battery low through, say, a room change or an early morning meeting, and also reduces throughput even when battery power is above 50%. Letting prime95 start only when the battery power is above a certain amount is stil by far the better option.
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Old 2012-09-17, 02:12   #11
swl551
 
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Default A work around if p95 does not get the feature.

Here is a script using WMI to get battery status. http://www.planet-source-code.com/vb...=8092&lngWId=4

There is probably a converted script to use PowerShell out there and seems more correct if you using Win7.

You could code up a mini battery monitor with the script and stop/start P95 accordingly

or if you want to access the information at a lower layer
http://msdn.microsoft.com/en-us/libr...(v=vs.85).aspx
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