Robert Carter's question about CPU Efficiency

Gary Roberts
Gary Roberts
Moderator
Joined: 9 Feb 05
Posts: 4,886
Credit: 29,240,002,810
RAC: 35,270,544
Topic 190139

I recently joined Einstein at Home with two computers. There is about a 30% difference in the floating point and integer speeds between the two computers, and the 'seconds of CPU time' of the fast machine is about half of the other one. The faster machine is completing about seven times as many work pieces per day however. The explanation seems to be in the "Average CPU efficiency" number which is .37 on the slower machine, and.99 on the other. How is the "Average CPU efficiency" number in the "Computer Summary" page generated? Thanks, Bob

Cheers,
Gary.

Gary Roberts
Gary Roberts
Moderator
Joined: 9 Feb 05
Posts: 4,886
Credit: 29,240,002,810
RAC: 35,270,544

RE: I recently joined

Quote:
I recently joined Einstein at Home with two computers. There is about a 30% difference in the floating point and integer speeds between the two computers, and the 'seconds of CPU time' of the fast machine is about half of the other one. The faster machine is completing about seven times as many work pieces per day however. The explanation seems to be in the "Average CPU efficiency" number which is .37 on the slower machine, and.99 on the other. How is the "Average CPU efficiency" number in the "Computer Summary" page generated? Thanks, Bob

Hi Bob,

Thank you for joining the EAH project!! It's good to have you on board.

I shifted your post here as this is a much more suitable place to get questions like this answered.

You are correct in assuming that Average CPU efficiency is the key parameter to look at for an answer. What it basically means is that your slower machine is only giving 37% of its total cpu cycles to EAH and 63% are going to other processes. However in this case there might be another answer. It's listed as a mobile celeron so I would imagine it's a laptop. Does it have any sort of thermal throttling? Does it reduce its clock speed when there is no keyboard activity? If you have it connected to the mains but running on a "conserve power" type setting, maybe it's doing just that and maybe this is causing BOINC to think that it's a lot slower than the benchmarks suggest?

Have a think about these sort of things and see if you can work out what's happening. I imagine if there really were another process eating up 63% of your CPU then you would probably know about it :).

Cheers,
Gary.

Michael Roycraft
Michael Roycraft
Joined: 10 Mar 05
Posts: 846
Credit: 157,718
RAC: 0

RE: I'm creating this

Message 19271 in response to (parent removed)

Quote:

I'm creating this thread as a "placeholder" for a message I'm going to move from where it has been inappropriately posted in the Science forum. I'm trying a "move" but the procedure needs a destination thread ID so I'm creating one. If I get it right, the post in question will end up here.

Edit: Well it got here OK :). I wonder if Robert Carter will be able to find it again :).

Gary,

I don't have an Intel, so I thought I'd ask you this: Do you have a P4 machine handy (running 5.x), to check if they're inherently running lower CPU efficiency? Because it they ordinarily go at 90+%, I'm guessing that Robert's Intel machine is either running something else that's very CPU-intensive, or that Boinc is often suspended but not closed (or Manager closed but not Daemon closed from System Tray). I believe that either of these scenarios would account for the low efficiency #s.

Regards,

Michael

microcraft
"The arc of history is long, but it bends toward justice" - MLK

Gary Roberts
Gary Roberts
Moderator
Joined: 9 Feb 05
Posts: 4,886
Credit: 29,240,002,810
RAC: 35,270,544

Michael, I have a PIII

Michael,

I have a PIII which started crunching a week ago on a 5.2.X BOINC. Its current value is 0.99518.

I have a P4 which started on 4.19 back in February but has been upgraded to 5.2.X about a week ago. Its current value is 0.99952.

As long as the OS is 2K or XP, (as the above are) I think the values are accurate.

I have a PIII running Me with the same history as the P4 above. Its current value is 1.087969.

I have a Celeron running 98SE+unofficial patchkit with the same history as the PIII/Me and its value is 1.573784. WOW!! 157% of the available cycles!! I always knew that patchkit was hot stuff :).

Seriously, Windows 9x systems just don't handle apps being preempted and left in memory all that well I think. Things got a lot better when Microsoft "borrowed" some ideas from unix :).

Getting back to Bob's problem - I just don't believe that his laptop could be running something else that cpu intensive without him knowing about it. I also don't think it's anything to do with the daemon running but not the Manager. I'm actually experimenting with having the daemon running and then firing up the Manager just to see what's going on. When the Manager is completely closed, the daemon continues on at full speed with nothing to steal cpu cycles. Seems to work very well.

Cheers,
Gary.

Michael Roycraft
Michael Roycraft
Joined: 10 Mar 05
Posts: 846
Credit: 157,718
RAC: 0

Gary, Yes, I'm still

Gary,

Yes, I'm still awake. My thinking is that maybe with the daemon running but no manager to order crunching, that time would rack up without fulltime crunching, lessening efficiency. Other thing is maybe preference to work fulltime, but some OpenGL-based screensaver. Just tossing around ideas here, speculation.

Regards,

Michael

(edit) When I was testing one of the 5.x clients (can't remember which, 5.2.1, I think), I accidentally left the project suspended for a few hours, and the next time I looked at my summary page, the efficiency had dropped from the familiar .99xx to a value closer to .90. I didn't keep an eagle eye on it, but I don't think that drop was coincidence.

microcraft
"The arc of history is long, but it bends toward justice" - MLK

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.