lag time

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Profile Doug Worrall
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Message 5474 - Posted: 7 Dec 2005, 22:53:34 UTC
Last modified: 7 Dec 2005, 22:55:25 UTC

Hello,
Have noticed with Rosetta W/U that are about 4 hours.
I lose usually at least 6 Minutes that are unaccounted for.The w/u presently has a lag time of 15 minutes with 20 to go.
Not a Big problem,could this P.C. be having problems.
No other experiments 4 others,donnot experience "Lag Time"
Sincerely
Doug Worrall
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Message 5478 - Posted: 7 Dec 2005, 23:07:28 UTC

I'm sorry, I have no idea what you are saying. Can you give an example, with numbers, and explain where the numbers come from?

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Message 5490 - Posted: 7 Dec 2005, 23:58:27 UTC

I'm afraid I'm not exactly familiar with how boinc calculates CPU time (it's changed from Win9x to Win2000/xp I believe...) but I think it could be simply the way your computer counts CPU time.

Is this one computer running other programs -- perhaps web browsing and MS Word? I think the "lag" might be because the client is actually counting CPU time -- time the CPU actually crunches for the program. When the CPU gets used for other things like games or just surfing the net, it takes time away from boinc.

That's my guess anyway, but I have never really paid enough attention to the actual coding of credit to be sure of myself here.
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Message 5491 - Posted: 8 Dec 2005, 0:00:51 UTC - in response to Message 5478.  
Last modified: 8 Dec 2005, 0:02:15 UTC

I'm sorry, I have no idea what you are saying. Can you give an example, with numbers, and explain where the numbers come from?

I apologise.
Basically for my last 4 hour and 10 Minute w/u,it took an xtra 15 minutes to crunch!Therfore the time was 4hours and 25 Minutes for a 4 Hour and 10
minute w/u?No other experiment has "Lag Time" and I can surf and Email with no
loss of Boinc "Time"
Doug
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Message 5505 - Posted: 8 Dec 2005, 0:59:22 UTC - in response to Message 5491.  
Last modified: 8 Dec 2005, 1:00:56 UTC

Basically for my last 4 hour and 10 Minute w/u,it took an xtra 15 minutes to crunch!


As Bill said.. can you "explain where the numbers come from"?

Are you comparing estimated CPU time (which can be highly inaccurate) to actual CPU time? Or CPU time to actual (clock) time? Or "task manager" (or Linux equivalent) CPU time on the project with BOINC reported time?

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Message 5534 - Posted: 8 Dec 2005, 6:39:47 UTC

How did you determine the 4hr 10min figure????
BOINC Wiki

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Message 5561 - Posted: 8 Dec 2005, 14:11:03 UTC - in response to Message 5534.  

How did you determine the 4hr 10min figure????



In your tab that gives start times and in work tab says w/u time.
I cannot understand why when I say a 4 hour W/U took 4 Hours and
15 Minutes.Therefore 15 missing minutes.If I crunch a 4 hour w/u,
it takes 4 Hours not 4 hours and 15 Minutes.
12000 credits from Climate with no Lag time.10,200 Einstein
No lag time same with Predictor LHC ect....
Rosetta takes usually about 8 xtra minutes on 4 hours.
That is non sensicle,that is why I am asking if this is a Rosetta
thing,or my Rosetta is mixed -up.
Sincerely
Doug
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Message 5570 - Posted: 8 Dec 2005, 15:13:41 UTC

Is your machine crunching Rosetta 100%? or are you crunching other projects?

If you're doing multiple projects you could be losing some time when the projects are switched.

I believe that Rosetta checkpoints 10 ten times. If your crunching Rosetta and your between checkpoints, say you're at 88% completion (ie. between the 80% and 90% checkpoints), and then you switch projects, you will loose the crunch time you did after 80% because when you switch back to Rosetta you'll start 80% not 88%.



Someone correct me if I'm wrong.
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Message 5625 - Posted: 8 Dec 2005, 19:39:30 UTC - in response to Message 5570.  

Is your machine crunching Rosetta 100%? or are you crunching other projects?

If you're doing multiple projects you could be losing some time when the projects are switched.

I believe that Rosetta checkpoints 10 ten times. If your crunching Rosetta and your between checkpoints, say you're at 88% completion (ie. between the 80% and 90% checkpoints), and then you switch projects, you will loose the crunch time you did after 80% because when you switch back to Rosetta you'll start 80% not 88%.



Someone correct me if I'm wrong.

Thanks Andrew,
Actually for me to be able to cruch Rosetta I must suspend all 3 other Experiments
to run Rosey succesfully.If a Benchmark happens during a Rosey W/U it fails.
If I quit Boinc in any way I will lose W/U.This Box is Linux which makes it difficult to explain.I dont get it,LOL.Just succesfully Downloaded Boinc
5.2.13 with ease.It,s a beaut.As for the explanation regarding "checkpoints"
Andrew,they make sense for other questions I donnot have to ask now.Thank
you very much Andrew for the answer to the easiest question I have ever
put on these Boards.
Did not see any Scientists,you guys are great {hands-on},same for the
{Boardwatchers?} ummm,brain block,you know whom you are,shoot,the Moderators.
Dohh,can I swear?,but why?Are there any {subcultred} jerks ever try
hacking or trying to mess up the Posts?Just curious.

Thanks All
Doug

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Message 5627 - Posted: 8 Dec 2005, 19:47:06 UTC - in response to Message 5534.  

How did you determine the 4hr 10min figure????



Thanks Jim,
Boinc Wiki is already on Firefox,Opera and Mozzila Suite.
To figure how long a W/U takes,look in your Message tab.Right down
the start time of that w/u.Once it has crunched its time.You simply
compare start time and actual crunching Time.Surfing Emailing donnot affect
the outcome of any W/U,Having 800Ram gives me lots of power.

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Message 5647 - Posted: 9 Dec 2005, 0:18:04 UTC - in response to Message 5627.  

To figure how long a W/U takes,look in your Message tab.Right down
the start time of that w/u.Once it has crunched its time.You simply
compare start time and actual crunching Time.Surfing Emailing donnot affect
the outcome of any W/U,Having 800Ram gives me lots of power.


You are comparing "CPU Time" to "clock time". CPU time will _always_ be less. Your computer must do many things, even if you are not surfing, emailing, or playing a game; it must update the clock on the computer (every second), it must refresh the video screen (many times per second, and even if this is done by separate hardware, that hardware must be refreshed from the CPU every so often), it must check to see if you have moved a mouse or hit a key, or if a network packet has come in...

In every "clock second", the computer probably does 100 things _other_ than just work on Rosetta. The fewer things it is doing, the closer the two numbers will come, but a "lag time" of a few minutes per hour is perfectly normal.

Also - to fix your problem with errors in Rosetta, change the preference "leave applications in memory when suspended" to YES. Then it will switch with other projects without a problem. It _will_ still give an error if you quit BOINC, at least sometimes.

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Message 5648 - Posted: 9 Dec 2005, 0:18:39 UTC - in response to Message 5625.  
Last modified: 9 Dec 2005, 0:24:55 UTC

Did not see any Scientists,you guys are great {hands-on},same for the
{Boardwatchers?} ummm,brain block,you know whom you are,shoot,the Moderators.
Dohh,can I swear?,but why?Are there any {subcultred} jerks ever try
hacking or trying to mess up the Posts?Just curious.


As a new "moderator", I'll speak up... I have not seen anyone _HERE_ trying to hack or mess up the posts. "Minor" swearing is not going to get _me_ upset - we operate under the assumption that we're all adults. If someone _complains_, then some moderator might edit your post or delete it; and I won't wait for a complaint if I see something truly "obscene", or especially anything that is a direct attack or threat on another participant.

My attitude is that a moderator is doing their job correctly if nobody knows they're there. Which probably means letting some things go that some others would step in and 'correct', but I'd rather save my effort and only "stomp" on someone that is totally out of control.

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Message 5664 - Posted: 9 Dec 2005, 5:16:23 UTC - in response to Message 5647.  

To figure how long a W/U takes,look in your Message tab.Right down
the start time of that w/u.Once it has crunched its time.You simply
compare start time and actual crunching Time.Surfing Emailing donnot affect
the outcome of any W/U,Having 800Ram gives me lots of power.


You are comparing "CPU Time" to "clock time". CPU time will _always_ be less. Your computer must do many things, even if you are not surfing, emailing, or playing a game; it must update the clock on the computer (every second), it must refresh the video screen (many times per second, and even if this is done by separate hardware, that hardware must be refreshed from the CPU every so often), it must check to see if you have moved a mouse or hit a key, or if a network packet has come in...

In every "clock second", the computer probably does 100 things _other_ than just work on Rosetta. The fewer things it is doing, the closer the two numbers will come, but a "lag time" of a few minutes per hour is perfectly normal.

Also - to fix your problem with errors in Rosetta, change the preference "leave applications in memory when suspended" to YES. Then it will switch with other projects without a problem. It _will_ still give an error if you quit BOINC, at least sometimes.


Thank you,
I have changed the applications to saved in memory,this will help tons.Thank
you all very much.This is all so interesting.
Sincerly
Doug
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Message boards : Number crunching : lag time



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