I'd be more concerned about the extra heat being put out by running your CPU at 100% all the time.

'Technically', your CPU runs at 100% all of the time. BOINC/SETI just takes up the time normally used by "System Idle Processes" (check your Task Manager whenever BOINC isn't running.)

"Technically" it doesn't. Many CPUs since the Pentium 4 have the ability to shut down parts of the processor that aren't in use to reduce the heat output. Running at 100% doesn't allow those parts to shut down, thus creating more heat on full load. Why do you think so many people in Number Crunching or on any hardware review site compare idle temperatures to full load?

The "System Idle Process" showing a loop of CPU cycles doing nothing hasn't been true for quite a while. The System Idle Process now shows simply that your CPU is exactly that: idle. Any OS supporting ACPI (Advanced Configuration and Power Management) (Windows 2000 on) supports the lower CPU throughput and thus reports actual idle time and not just a loop taking all spare cycles.

This is semantics. Is your car "running" while at a stop sign idling with no forward progress?

The CPU runs (operates) as long as power is applied.

To follow the same analogy. Does your car use as much fuel and produce as much heat at idle as it does at full throttle? The answer of course is no.

---

BOINC WIKI

BOINC is designed to relinquish all CPU cycles to other apps that need it by running the science app at the lowest priority (so that other apps take precedence).

Takes awhile to realize that, though...

I'd be more concerned about the extra heat being put out by running your CPU at 100% all the time.

'Technically', your CPU runs at 100% all of the time. BOINC/SETI just takes up the time normally used by "System Idle Processes" (check your Task Manager whenever BOINC isn't running.)

But if you have an excellent fan/heat sink on your CPU, and an adequate amount of fans in your case, then this is also a non-issue.

You might want to upgrade to 5.10.20. There was a bug fixed that caused some Windows machines to be sluggish (and also caused work to restart a great deal more often than it should have).

---

BOINC WIKI

I don't have any special fans or heat sinks in my Dell Dimension 8400. I don't do much compute-intensive stuff with the computer except BOINC, but now I'm wondering whether leaving it at 100% CPU Usage all the time might damage or otherwise stress the system and shorten its life.

Knowing Dell's quality, I'm sure you have a fan/heat sink on top of the CPU itself (every CPU these days does), and I'm sure there's at least an exhaust fan in the back. If the airflow is designed properly in the case (and I'd have to have extensive knowledge of that particular case to know for certain), then it may be enough.

As for leaving it run 100% all the time damaging or "stressing" the system, and assuming cooling is indeed not a problem, then I wouldn't even worry about it. In all my years with computers, I have not seen sufficient evidence that proves that such things will considerably shorten a system's life. There's a higher probability that you'll replace the entire system long before the CPU ever gives out from stress. I know some people on these boards that are still using their Pentium II 400MHz CPUs that they started out with back at the beginning of SETI Classic in 1999 (almost nine years) without a single problem to this day.

---

I'd be more concerned about the extra heat being put out by running your CPU at 100% all the time.

'Technically', your CPU runs at 100% all of the time. BOINC/SETI just takes up the time normally used by "System Idle Processes" (check your Task Manager whenever BOINC isn't running.)

"Technically" it doesn't. Many CPUs since the Pentium 4 have the ability to shut down parts of the processor that aren't in use to reduce the heat output. Running at 100% doesn't allow those parts to shut down, thus creating more heat on full load. Why do you think so many people in Number Crunching or on any hardware review site compare idle temperatures to full load?

The "System Idle Process" showing a loop of CPU cycles doing nothing hasn't been true for quite a while. The System Idle Process now shows simply that your CPU is exactly that: idle. Any OS supporting ACPI (Advanced Configuration and Power Management) (Windows 2000 on) supports the lower CPU throughput and thus reports actual idle time and not just a loop taking all spare cycles.

This is semantics. Is your car "running" while at a stop sign idling with no forward progress?

The CPU runs (operates) as long as power is applied.

No, it's not semantics. The point is, when you "turn on" that second CPU and run things at full bore, extra heat can be generated.

It would be the difference between your car being idle most of the time (or even half the time) as opposed to holding the accelerator down all the way all the time. I guarantee your engine will get hotter then than it would during idle.

Your CPU may take the same amount of volts as long as power is supplied, but it can vary in how many watts it uses, which is what we pay for in our electric bills. Why do you think those aforementioned review sites factor in power usage as something to think about when purchasing a system? Power usage is becoming very important to many people.

For what it's worth, I tend to leave my Task Manager in the notification area "tray" to see my CPU activity level. I have hyperthreading turned on. When I set BOINC gen prefs to use 1 CPU, and ran SETI, the icon showed 50% CPU usage almost all the time. When I just upped the gen prefs to use 2 CPUs, the Task Manager icon shows the CPU Usage at 100% all the time. I have assumed that this CPU usage corresponded to, well, CPU usage - computing and generating heat. I've assumed System Idle Process is just "other", whatever isn't being used by CPU is just reported under that, but it's not actual work, or if it is an idle loop, it's not using as much energy and generating as much heat as when that little green meter level is fully green.

I don't have any special fans or heat sinks in my Dell Dimension 8400. I don't do much compute-intensive stuff with the computer except BOINC, but now I'm wondering whether leaving it at 100% CPU Usage all the time might damage or otherwise stress the system and shorten its life.

Interesting stuff.

-- garyZ

---

I'd be more concerned about the extra heat being put out by running your CPU at 100% all the time.

'Technically', your CPU runs at 100% all of the time. BOINC/SETI just takes up the time normally used by "System Idle Processes" (check your Task Manager whenever BOINC isn't running.)

"Technically" it doesn't. Many CPUs since the Pentium 4 have the ability to shut down parts of the processor that aren't in use to reduce the heat output. Running at 100% doesn't allow those parts to shut down, thus creating more heat on full load. Why do you think so many people in Number Crunching or on any hardware review site compare idle temperatures to full load?

The "System Idle Process" showing a loop of CPU cycles doing nothing hasn't been true for quite a while. The System Idle Process now shows simply that your CPU is exactly that: idle. Any OS supporting ACPI (Advanced Configuration and Power Management) (Windows 2000 on) supports the lower CPU throughput and thus reports actual idle time and not just a loop taking all spare cycles.

This is semantics. Is your car "running" while at a stop sign idling with no forward progress?

The CPU runs (operates) as long as power is applied.

No, it's not semantics. The point is, when you "turn on" that second CPU and run things at full bore, extra heat can be generated.

It would be the difference between your car being idle most of the time (or even half the time) as opposed to holding the accelerator down all the way all the time. I guarantee your engine will get hotter then than it would during idle.

Your CPU may take the same amount of volts as long as power is supplied, but it can vary in how many watts it uses, which is what we pay for in our electric bills. Why do you think those aforementioned review sites factor in power usage as something to think about when purchasing a system? Power usage is becoming very important to many people.

---

I'd be more concerned about the extra heat being put out by running your CPU at 100% all the time.

'Technically', your CPU runs at 100% all of the time. BOINC/SETI just takes up the time normally used by "System Idle Processes" (check your Task Manager whenever BOINC isn't running.)

"Technically" it doesn't. Many CPUs since the Pentium 4 have the ability to shut down parts of the processor that aren't in use to reduce the heat output. Running at 100% doesn't allow those parts to shut down, thus creating more heat on full load. Why do you think so many people in Number Crunching or on any hardware review site compare idle temperatures to full load?

The "System Idle Process" showing a loop of CPU cycles doing nothing hasn't been true for quite a while. The System Idle Process now shows simply that your CPU is exactly that: idle. Any OS supporting ACPI (Advanced Configuration and Power Management) (Windows 2000 on) supports the lower CPU throughput and thus reports actual idle time and not just a loop taking all spare cycles.

This is semantics. Is your car "running" while at a stop sign idling with no forward progress?

The CPU runs (operates) as long as power is applied.

I'd be more concerned about the extra heat being put out by running your CPU at 100% all the time.

'Technically', your CPU runs at 100% all of the time. BOINC/SETI just takes up the time normally used by "System Idle Processes" (check your Task Manager whenever BOINC isn't running.)

"Technically" it doesn't. Many CPUs since the Pentium 4 have the ability to shut down parts of the processor that aren't in use to reduce the heat output. Running at 100% doesn't allow those parts to shut down, thus creating more heat on full load. Why do you think so many people in Number Crunching or on any hardware review site compare idle temperatures to full load?

The "System Idle Process" showing a loop of CPU cycles doing nothing hasn't been true for quite a while. The System Idle Process now shows simply that your CPU is exactly that: idle. Any OS supporting ACPI (Advanced Configuration and Power Management) (Windows 2000 on) supports the lower CPU throughput and thus reports actual idle time and not just a loop taking all spare cycles.

---

BOINC is designed to relinquish all CPU cycles to other apps that need it by running the science app at the lowest priority (so that other apps take precedence).

Takes awhile to realize that, though...

I'd be more concerned about the extra heat being put out by running your CPU at 100% all the time.

'Technically', your CPU runs at 100% all of the time. BOINC/SETI just takes up the time normally used by "System Idle Processes" (check your Task Manager whenever BOINC isn't running.)

But if you have an excellent fan/heat sink on your CPU, and an adequate amount of fans in your case, then this is also a non-issue.

---

Now I'll see whether that adversely affects my "regular" computing tasks (web browsing, word processing, Quicken, etc.). The CPU is at 100% all the time now, but if it doesn't affect the other stuff I do, I'm happy to let the cycles go to something worthwhile.

It certainly shouldn't affect your other computing habits! I'm able to run BOINC 24/7 while browsing the web, watching videos, burning a CD/DVD, copying/moving files over my network and running a Adware scan all at the same time. Of course, the more processors you have, the more multitasking you can do before being bogged down, so it helps that I have two dual cores in my system! ;-)

BOINC is designed to relinquish all CPU cycles to other apps that need it by running the science app at the lowest priority (so that other apps take precedence). I'd be more concerned about the extra heat being put out by running your CPU at 100% all the time. But if you have an excellent fan/heat sink on your CPU, and an adequate amount of fans in your case, then this is also a non-issue.

Thanks again all.

You're welcome.

---

Do I have it wrong? Can BOINC only run one WU at a time?

(Dell Dimension 8400, Windows XP Pro SP2, 1GB, hyperthreading turned on and SETI BOINC typically uses 50% CPU as shown in Task Manager)

If you have a system that supports Hyperthreading turned on, and at any given moment the CPU is only at 50% usage, that means your preferences are set to only use a single CPU. To take advantage of that second virtual/logical CPU, you must change your preferences online to "On multiprocessors, use at most:" to 2.

THAT did it! Thanks!
Now I'll see whether that adversely affects my "regular" computing tasks (web browsing, word processing, Quicken, etc.). The CPU is at 100% all the time now, but if it doesn't affect the other stuff I do, I'm happy to let the cycles go to something worthwhile.

Thanks again all.

-- garyZ

Oh, yes, even on a dual CPU system there will be times when 2 of one project or the other will be running.

---

BOINC WIKI

Do I have it wrong? Can BOINC only run one WU at a time?

(Dell Dimension 8400, Windows XP Pro SP2, 1GB, hyperthreading turned on and SETI BOINC typically uses 50% CPU as shown in Task Manager)

If you have a system that supports Hyperthreading turned on, and at any given moment the CPU is only at 50% usage, that means your preferences are set to only use a single CPU. To take advantage of that second virtual/logical CPU, you must change your preferences online to "On multiprocessors, use at most:" to 2.

THAT did it! Thanks!
Now I'll see whether that adversely affects my "regular" computing tasks (web browsing, word processing, Quicken, etc.). The CPU is at 100% all the time now, but if it doesn't affect the other stuff I do, I'm happy to let the cycles go to something worthwhile.

Thanks again all.

-- garyZ

---

Do I have it wrong? Can BOINC only run one WU at a time?

(Dell Dimension 8400, Windows XP Pro SP2, 1GB, hyperthreading turned on and SETI BOINC typically uses 50% CPU as shown in Task Manager)

If you have a system that supports Hyperthreading turned on, and at any given moment the CPU is only at 50% usage, that means your preferences are set to only use a single CPU. To take advantage of that second virtual/logical CPU, you must change your preferences online to "On multiprocessors, use at most:" to 2.

---

Thanks very much, John. I appreciate the info. Now I need to decide whether to let my computer juggle multiple projects, or have it focus on just one (probably SETI, since, as my first, I have a sentimental attachment to that one).

-- garyZ

---

I'm a longstanding SETI@home user/runner, now upgraded of course to BOINC. I recently looked into the other available grid projects, and decided to try running rosetta too.

I thought the two projects would run simultaneously on my machine and share the CPU, but so far they seem to run separately - first one or two WU from one project, then one or two from the other.

I have my prefs set up to give SETI "200%" of Resource Share, and Rosetta at 100% (I initially tried 50:50, but that wasn't sharing either).

Do I have it wrong? Can BOINC only run one WU at a time?

(Dell Dimension 8400, Windows XP Pro SP2, 1GB, hyperthreading turned on and SETI BOINC typically uses 50% CPU as shown in Task Manager)

Thanks for helping me learn more about this.

-- garyZ

BOINC allows one task to run on each CPU. So a single CPU system will indeed switch between tasks (the default is one hour). There are a couple of reasons for this. 1) There is a cost to task switches, and the fewer that there are, the higher the total throughput. 2) If too many things are running at the same time, the CPU can be constantly asking for things that are not in the CPU cache(s), or even if it is bad enough memory. If a CPU cache miss occurs, then memory is queried and this is slower than the cache. If a memory miss occurs, then the data has to come from disk - which is orders of magnitude slower.

The user is allowed to further restrict the total amount of tasks running at any given time.

---

BOINC WIKI

I'm a longstanding SETI@home user/runner, now upgraded of course to BOINC. I recently looked into the other available grid projects, and decided to try running rosetta too.

I thought the two projects would run simultaneously on my machine and share the CPU, but so far they seem to run separately - first one or two WU from one project, then one or two from the other.

I have my prefs set up to give SETI "200%" of Resource Share, and Rosetta at 100% (I initially tried 50:50, but that wasn't sharing either).

Do I have it wrong? Can BOINC only run one WU at a time?

(Dell Dimension 8400, Windows XP Pro SP2, 1GB, hyperthreading turned on and SETI BOINC typically uses 50% CPU as shown in Task Manager)

Thanks for helping me learn more about this.

-- garyZ

---