Benutzer:Rdiez/DonatingIdleComputerTime - Versionsgeschichte

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2015-04-04T13:25:28Z

Weiterleitung nach Benutzer:Rdiez/PageRemoved erstellt

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Rdiez am 10. November 2014 um 20:37 Uhr

2014-11-10T20:37:50Z

Rdiez am 10. November 2014 um 20:34 Uhr

2014-11-10T20:34:25Z

Rdiez am 7. November 2014 um 18:35 Uhr

2014-11-07T18:35:47Z

Rdiez am 7. November 2014 um 18:34 Uhr

2014-11-07T18:34:23Z

Rdiez am 6. November 2014 um 21:31 Uhr

2014-11-06T21:31:02Z

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Rdiez am 4. November 2014 um 22:20 Uhr

2014-11-04T22:20:45Z

Rdiez am 3. November 2014 um 21:25 Uhr

2014-11-03T21:25:54Z

Rdiez am 2. November 2014 um 19:04 Uhr

2014-11-02T19:04:47Z

Rdiez am 2. November 2014 um 18:30 Uhr

2014-11-02T18:30:33Z

@@ Zeile 204: / Zeile 204: @@
 *** 8 GiB RAM DDR3-1066
 **Consumption:
 *** Idle consumption: 17 W <br/> The fan normally runs every now a then for a little while.
 *** With SETI@home and ''ignore_nice_load'' (933 MHz): 30 W (at 13 W a 76% increase from idle)  <br/> The fan runs permanently at half speed but makes almost as much noise as when at full speed.

@@ Zeile 205: / Zeile 205: @@
 **Consumption:
 *** Idle consumption: 17 W <br/> The fan normally runs every now a then for a little while.
-*** With SETI@home: 37 W (at 20 W a 118% increase) <br/> The fan runs at full speed and is therefore louder.
+*** With SETI@home and ''ignore_nice_load'' (933 MHz): 30 W (at 13 W a 76% increase from idle)  <br/> The fan runs permanently at half speed but makes almost as much noise as when at full speed.
 * Desktop PC:

@@ Zeile 216: / Zeile 216: @@
 *** 26'' full HD flat screen
 ** Consumption:
 *** PC-only idle: 87 W
 *** With monitor turned on: 134 W (at 117 W a 688% increase from the laptop) <br/> Part of the increase is probably due to the graphics card now doing some work.

@@ Zeile 382: / Zeile 382: @@
 Leave the following command running on a separate window in order to monitor the current frequency in realtime:
-   sudo watch -n 0.2 cat /sys/devices/system/cpu/cpu*/cpufreq/cpuinfo_cur_freq
+   watch --interval 0.2 cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_cur_freq
 You need to set configuration option ''ignore_nice_load'' to 1, so that low-priority processes do not make the CPU frequency increase:

@@ Zeile 101: / Zeile 101: @@
 ==== "Computing preferences" issues ====
-Option "Do work after idle for xx minutes" does not seem to work under Kubuntu Linux. After setting it to 1 minute, processing never resumes. It should also allow the user to specify a delay of a few seconds or even milliseconds. Otherwise, short-lived CPU usage spikes may prevent SETI@home from running at all. In any case, one minute is far too long for a CPU to idle around.
+BOINC has a "Computing preferences" dialog which shows a few more settings in the "Advanced view" mode.
-TODO: Write the rest of this section.
+There is a "While computer is in use" option. The term "in use" here means no mouse or keyboard activity, which is confusing, as there is a processor usage setting below, but that is another kind of "in use". It is also a rather silly option. First of all, if you are not using the computer, you will probably turn it off or let it sleep to save energy. I do not see the point in stopping background computations while you are typing a letter. And you could also be using your computer even if you are not actively moving the mouse around. You could be connected over SSH, be watching a movie or waiting for some compilation to finish. To top it all, this option does not work under Kubuntu Linux 14.04: if you turn it off, computation never starts.
 ==== The process priority is not quite right ====
@@ Zeile 115: / Zeile 135: @@
 My guess is, if you are using the "simple view", you do not care which tasks a project is made of. You just want to see a reassuring message that all of your projects are running well (and not just the one current task in the one current project). And you want a big "Pause" button at the top.
-==== User interface quirks under Linux  ====
+==== User interface quirks  ====
 Under Kubuntu Linux, closing the window does not close it, it just minimises it to the taskbar. And right-clicking on the taskbar icon makes the menu pop-up and immediately go away. You have to hold the right mouse button down. This non-standard behaviour is annoying.
@@ Zeile 125: / Zeile 147: @@
 * The system is busy with higher-priority processes. <br/> BOINC seems to realise that the project is not getting any CPU time at the moment. The Status column should then say "computer busy". On the "simple view", you do see an overall "Suspended - CPU is busy" message.
 * The user chooses menu option "Activity/Suspend". <br/> In case the user forgets later on, the Status column should say "all BOINC activity suspended by the user". This is different from pausing just the one project, which does display "suspended by the user".
 == Power consumption ==
@@ Zeile 221: / Zeile 249: @@
 For normal consumer loads, the performance impact should not be too high.
-=== Impact on foreground tasks ===
+=== Impact on foreground CPU tasks ===
 BOINC tasks run with the lowest-possible process priority, sometimes called 'idle' priority. Under Kubuntu Linux, the System Monitor shows for those processes a 'nice' level of 19 and a scheduling policy of 'batch'. Under Microsoft Windows, the Task Manager displays a "Low" priority.
@@ Zeile 278: / Zeile 306: @@
 The upshot is: if you are running background low-priority tasks, your normal processes will execute more slowly than expected during the first seconds. Exactly how long depends on some scheduler heuristics. The behaviour of the Linux CPU scheduler is definitely too unpredictable for my liking.
 === CPU usage meters rendered useless ===
@@ Zeile 288: / Zeile 328: @@
 TODO: Write the rest of this article.

@@ Zeile 53: / Zeile 53: @@
 I tested version 7.2.42 (latest as of october 2014) under Kubuntu Linux 14.04 and under Microsoft Windows 7.
-=== You need to accept a software license ===
+=== Installation ===
 The first thing you'll notice when installing BOINC is that you need to accept the LGPL license. As a anonymous volunteer, you are probably not in the mood to accept any license. In fact, you do not actually need to accept this license in order to use the software. Section "9. Acceptance Not Required for Having Copies" of the GPL (which the LGPL is based on) starts with "You are not required to accept this License, since you have not signed it".
@@ Zeile 59: / Zeile 61: @@
 I am not a lawyer, but I suspect that the additional clause "Restrictions: You may use this software on a computer system only if you own the system or have the permission of the owner", while a valid warning about a potential, common-sense issue, is probably formally incompatible with the GPL, which admits no additional restrictions about how the software may be used. I guess the BOINC project could place this kind of restriction in their service usage policy, but if you think about it, it does not actually make sense.
-=== Replacing your screensaver by default ===
+==== Replacing your screensaver by default ====
 On Windows, the default installation will replace your screensaver. The BOINC markerting department is probably hoping to get some free advertisement space on your PC monitor. They could just suggest that you use the BOINC screensaver, because it is cool, or mention that it is "good" advertising and you may want to help spread the platform too. But making it the default, and having to press the "Advanced" button first so that you can untick that option, is rather cheeky. Definitely not the right way to treat your volunteers.
-=== Unnecessary system restart under Windows ===
+==== Unnecessary system restart under Windows ====
 On Ubuntu Linux, you do not need to restart your PC after installing BOINC. On Windows, restarting the PC should not be necessary either. Nowadays you can install and remove Windows services without a restart.
-=== Why you need a user account ===
+==== Why you need a user account ====
 The first time BOINC starts, you are given the chance to add a computing project. I selected SETI@home, and I was prompted to create a new account or use an existing one for that particular project. I do not know yet whether this applies to all projects, or if it is specific to SETI@home, but the log-in dialog box looked generic to all BOINC projects.
@@ Zeile 75: / Zeile 77: @@
 There is virtually no user-identification mechanism in place, so you can make up your name etc. when creating an account. The BONIC infrastructure does not really trust you anyway. Every piece of data is computed twice on separate volunteer computers, effectively halving the available processing power. This way, faulty computers or even malicious participants stand out quickly.
-==== Account scoring ====
+===== Account scoring =====
 Distributed computing platforms tend to implement some sort of scoring, so that your own contributions are visibly acknowledged. Some platforms are trying to promote a sense of "community" and offer different rewards as an incentive, like your name appearing on the "top 100" contributors list, or some special mention or price if your computer happens to be the one that finds some interesting computational result. When SETI@home introduced a competitive aspect, it even prompted attempts to 'cheat' the system.
@@ Zeile 85: / Zeile 87: @@
 While I do not mind this kind of corporate marketing, I do not see the need to participate myself. The computing software could just create some random ID on each PC, and display a message window if it really needs the user's attention. Having a user account and playing such social games should be entirely optional.
-=== Surprise! Surprise!  ===
+=== Running BOINC ===
 After choosing a project, computation begins. The first thing you will notice is that your CPU usage goes up to 100 %, which is a good sign.
@@ Zeile 94: / Zeile 98: @@
 Once you have become aware of the problems, if you look carefully at BOINC's documentation and start searching around on the Internet, the underlying problems will start to emerge. The BOINC documentation does not feature these issues prominently or thoroughly enough. New users are presented the buzzwords and the hype first, and are not given initial advice about what to expect. Again, this is no proper way to treat your volunteers.
 == Power consumption ==
@@ Zeile 214: / Zeile 245: @@
 Check out section "Measurements on my home computers" above for the system configuration. Under Microsoft Windows, I was using the [https://en.wikipedia.org/wiki/Cygwin Cygwin environment].
-This is the foreground task, with so many parallel processes as logical CPU cores. Each process executes many short-lived subprocesses sequentially:
+==== Foreground task with many short-lived subprocesses ====
    Linux:
@@ Zeile 229: / Zeile 262: @@
 Running a parallel SETI@home BOINC project in the background makes the foreground task take 155 % longer to complete on my Linux laptop and 70 % longer on my Windows PC.
 The following foreground task does not run any child processes:
@@ Zeile 236: / Zeile 271: @@
 With this workload, the performance impact is much lower. On the Windows PC, the difference is small, but not so on the Linux laptop, where running the low-priority synthetic task or SETI@home in the background yields 70 % longer execution times. You can see with KDE's System Monitor that processes with a "Niceness" of "(Batch) 19" are still getting their fare share of CPU time, even though other processes with a "Niceness" of "0" are permanently ready to run.
-== TODO ==
+Interestingly enough, this did not happen on a second Linux PC with an 4-core Intel Core i5 CPU running the same operating system version. On that second system, short foreground tasks often (but not always) take longer to run, but long-running foreground tasks do get all of the available CPU time, and background low-priority tasks do not run anymore as expected.
-TODO: Write the rest of the article.
+TODO: Write the rest of this article.

@@ Zeile 138: / Zeile 138: @@
 ** Specs:
 *** Kubuntu Linux 14.04
-*** Intel Core i3-380M CPU with 2 cores and Hyper-Threading, 2.53 Mhz
+*** Intel Core i3-380M CPU with 2 cores and Hyper-Threading, 2.53 Mhz (min 933 MHz)
 *** 8 GiB RAM DDR3-1066
 **Consumption: