Hi,
I don't know if this is the correct forum where ask my question, but since it is cgminer related I start from here

I've got a five 5870 rig I've just set up, it runs xubuntu 11.10 with catalyst 11.8 (the one that installs using xubuntu proprietary drivers applet) and I've installed AMD SDK 2.4.
If I don't use GPU_USE_SYNC_OBJECTS=1 CPU usage goes to 90%, If I use it, on the other hand, cgminer uses from 20 to 35% of CPU and CPU is a sempron 2.8 Ghz
This is with intensity 5 and standard 2 threads per GPU (a single thread per GPU makes little difference).
My question is: how much CPU should cgminer use? How much uses it on your multi-gpu rigs?
TIA.
spiccioli.
ps. my other two rigs have 2 GPUs each and with sync objects use very little cpu (less than 5%).
This is cgminer -ndevs output, note it says AMD SDK 2.5 but I've installed 2.4 following kanoi recipe
https://github.com/kanoi/linux-usb-cgminer/blob/master/linux-usb-cgminer$ cgminer/cgminer -ndevs
[2012-02-25 19:38:05] CL Platform 0 vendor: Advanced Micro Devices, Inc.
[2012-02-25 19:38:05] CL Platform 0 name: AMD Accelerated Parallel Processing
[2012-02-25 19:38:05] CL Platform 0 version: OpenCL 1.1 AMD-APP-SDK-v2.5 (793.1)
[2012-02-25 19:38:05] Platform 0 devices: 5
[2012-02-25 19:38:05] GPU 0 ATI Radeon HD 5800 Series hardware monitoring enabled
[2012-02-25 19:38:05] Setting GPU 0 engine clock to 830
[2012-02-25 19:38:05] Setting GPU 0 memory clock to 160
[2012-02-25 19:38:05] Setting GPU 0 voltage to 1.050
[2012-02-25 19:38:05] GPU 1 ATI Radeon HD 5800 Series hardware monitoring enabled
[2012-02-25 19:38:05] Setting GPU 1 engine clock to 830
[2012-02-25 19:38:05] Setting GPU 1 memory clock to 160
[2012-02-25 19:38:05] Setting GPU 1 voltage to 1.050
[2012-02-25 19:38:05] GPU 2 ATI Radeon HD 5800 Series hardware monitoring enabled
[2012-02-25 19:38:05] Setting GPU 2 engine clock to 830
[2012-02-25 19:38:05] Setting GPU 2 memory clock to 160
[2012-02-25 19:38:05] Setting GPU 2 voltage to 1.050
[2012-02-25 19:38:05] GPU 3 ATI Radeon HD 5800 Series hardware monitoring enabled
[2012-02-25 19:38:05] Setting GPU 3 engine clock to 830
[2012-02-25 19:38:05] Setting GPU 3 memory clock to 160
[2012-02-25 19:38:05] Setting GPU 3 voltage to 1.050
[2012-02-25 19:38:05] GPU 4 ATI Radeon HD 5800 Series hardware monitoring enabled
[2012-02-25 19:38:05] Setting GPU 4 engine clock to 830
[2012-02-25 19:38:05] Setting GPU 4 memory clock to 160
[2012-02-25 19:38:05] Setting GPU 4 voltage to 1.050
[2012-02-25 19:38:05] 5 GPU devices max detected