Same problem here. Intel Quad Core QX9650 @3Ghz Motherboard ASUS P5Q-E 4GB RAM CPU Scaling works in Windows. Tried acpi-cpufreq powernow-k8 speedstep-centrino all of them just in case, with same result uname -r 2.6.26-2-amd64 lsmod: Module Size Used by nvidia 10262056 36 ppdev 11656 0 parport_pc 31016 0 lp 14724 0 parport 41776 3 ppdev,parport_pc,lp ipv6 288328 20 cpufreq_powersave 6400 0 cpufreq_stats 9120 0 cpufreq_userspace 8452 0 cpufreq_ondemand 11792 0 freq_table 9344 2 cpufreq_stats,cpufreq_ondemand cpufreq_conservative 11784 0 fuse 53184 4 sbp2 25356 0 loop 19468 0 snd_hda_intel 436440 2 snd_pcm_oss 41760 0 snd_mixer_oss 18816 1 snd_pcm_oss snd_pcm 81672 2 snd_hda_intel,snd_pcm_oss snd_seq_dummy 7428 0 snd_seq_oss 33280 0 snd_seq_midi 11072 0 snd_rawmidi 26784 1 snd_seq_midi snd_seq_midi_event 11904 2 snd_seq_oss,snd_seq_midi snd_seq 54304 6 snd_seq_dummy,snd_seq_oss,snd_seq_midi,snd_seq_midi_event snd_timer 25744 2 snd_pcm,snd_seq snd_seq_device 11668 5 snd_seq_dummy,snd_seq_oss,snd_seq_midi,snd_rawmidi,snd_seq psmouse 42268 0 i2c_i801 13596 0 pcspkr 7040 0 serio_raw 9860 0 i2c_core 27936 2 nvidia,i2c_i801 snd 63688 13 snd_hda_intel,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_seq_oss,snd_rawmidi,snd_seq,snd_timer,snd_seq_device soundcore 12064 1 snd button 11680 0 snd_page_alloc 13072 2 snd_hda_intel,snd_pcm intel_agp 31856 0 evdev 14208 4 ext3 124944 2 jbd 51240 1 ext3 mbcache 12804 1 ext3 sg 36576 0 usbhid 45920 0 hid 41664 1 usbhid ff_memless 9224 1 usbhid sr_mod 19652 0 cdrom 37928 1 sr_mod sd_mod 29376 6 pata_marvell 8832 0 usb_storage 95680 0 ata_generic 10116 0 ata_piix 22660 5 ahci 33036 0 libata 165600 4 pata_marvell,ata_generic,ata_piix,ahci scsi_mod 160760 6 sbp2,sg,sr_mod,sd_mod,usb_storage,libata dock 14112 1 libata floppy 61672 0 ohci1394 32692 0 skge 41744 0 ieee1394 93816 2 sbp2,ohci1394 sky2 48004 0 ide_pci_generic 9220 0 [permanent] ide_core 128284 1 ide_pci_generic ehci_hcd 35980 0 uhci_hcd 25760 0 thermal 22816 0 processor 42304 1 thermal fan 9352 0 thermal_sys 17728 3 thermal,processor,fan cat /proc/cpuinfo: processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 23 model name : Intel(R) Core(TM)2 Extreme CPU X9650 @ 3.00GHz stepping : 7 cpu MHz : 2999.673 cache size : 6144 KB physical id : 0 siblings : 4 core id : 0 cpu cores : 4 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 10 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good pni monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr sse4_1 lahf_lm bogomips : 6003.35 clflush size : 64 cache_alignment : 64 address sizes : 36 bits physical, 48 bits virtual power management: processor : 1 vendor_id : GenuineIntel cpu family : 6 model : 23 model name : Intel(R) Core(TM)2 Extreme CPU X9650 @ 3.00GHz stepping : 7 cpu MHz : 2999.673 cache size : 6144 KB physical id : 0 siblings : 4 core id : 1 cpu cores : 4 apicid : 1 initial apicid : 1 fpu : yes fpu_exception : yes cpuid level : 10 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good pni monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr sse4_1 lahf_lm bogomips : 5999.37 clflush size : 64 cache_alignment : 64 address sizes : 36 bits physical, 48 bits virtual power management: processor : 2 vendor_id : GenuineIntel cpu family : 6 model : 23 model name : Intel(R) Core(TM)2 Extreme CPU X9650 @ 3.00GHz stepping : 7 cpu MHz : 2999.673 cache size : 6144 KB physical id : 0 siblings : 4 core id : 2 cpu cores : 4 apicid : 2 initial apicid : 2 fpu : yes fpu_exception : yes cpuid level : 10 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good pni monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr sse4_1 lahf_lm bogomips : 5999.40 clflush size : 64 cache_alignment : 64 address sizes : 36 bits physical, 48 bits virtual power management: processor : 3 vendor_id : GenuineIntel cpu family : 6 model : 23 model name : Intel(R) Core(TM)2 Extreme CPU X9650 @ 3.00GHz stepping : 7 cpu MHz : 2999.673 cache size : 6144 KB physical id : 0 siblings : 4 core id : 3 cpu cores : 4 apicid : 3 initial apicid : 3 fpu : yes fpu_exception : yes cpuid level : 10 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good pni monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr sse4_1 lahf_lm bogomips : 5999.42 clflush size : 64 cache_alignment : 64 address sizes : 36 bits physical, 48 bits virtual power management: