| Author | Message | ||
     Ole Tar (oletar) New member Username: oletar Post Number: 2 Registered: 05-2007 |
Dear Robert, I use FlexPDE for 1 year. My computer has the following parameters: Dell Latitude D630 Intel Core 2 Duo CPU T7500 @ 2.20 GHz, 4 Gb RAM Any PDE problem causes CPU usage 50-60 %. For example, the problem, which I solve right how has Nodes 8969 Cells 4434 Unknowns 26920 Mem(K) 129858 Windows Task manager shows 53-57 % CPU Usage. I wonder why the problem that requires only 130 Mb memory loads the computer with 4Gb RAM to that extent? Morover, the same level of CPU usage remains after finishing calculation. I have to exit FlexPDE in order to decrease the usage of CPU. Is it a normal situation or something is wrong? Best regards, oletar | ||
| Robert G. Nelson (rgnelson) Moderator Username: rgnelson Post Number: 1054 Registered: 06-2003 |
1. You have a dual core processor. FlexPDE 5 is primarily a single-thread application. So when FlexPDE is fully using one of the processors, the other is idle. Ergo: 50% CPU usage. [You can ask FlexPDE to use the second processor with SELECT THREADS=2. Version 5 can use two processors only in the conjugate gradient solver, so you will see the usage alternate between 50% and 80%-90%, depending on which phase of the computation is active. FlexPDE version 6 will be fully multi-threaded. No release date has been set for version 6.] 2. When the job finishes, FlexPDE goes into a "wait for event" loop. The system timer appears to manifest as an event, so FlexPDE executes briefly each 10ms or so while it waits. If there is no other task in the machine waiting for service, FlexPDE will alternate with the "System Idle" task, each recieving 50% of the available (idle) CPU time. If you start another task, the FlexPDE usage will drop to a very small amount. |