wsb@intrepid:~$ nvclock -s40
nvclock: invalid option -- '4'
wsb@intrepid:~$ nvclock -S50
Changing Smartdimmer level from 40% to 50%
New Smartdimmer level: 50%                
wsb@intrepid:~$ nvclock -i
-- General info --        
Card:           nVidia Geforce 8400M GT
Architecture:   G86 A2                 
PCI id:         0x426                  
GPU clock:      182.248 MHz            
Bustype:        PCI-Express            

-- Shader info --
Clock: 594.000 MHz
Stream units: 16 (1b)
ROP units: 4 (1b)    
-- Memory info --    
Amount:         64 MB
Type:           128 bit DDR3
Clock:          601.712 MHz 

-- PCI-Express info --
Current Rate:   16X   
Maximum rate:   16X

-- Smartdimmer info --
Backlight level: 50%

-- Sensor info --
Sensor: GPU Internal Sensor
GPU temperature: 49C

-- VideoBios information --
Version: 60.86.3b.00.23
Signon message: G86 e415 SKU 0001 VGA BIOS
Performance level 0: gpu 275MHz/shader 550MHz/memory 301MHz/1.15V/100%
Performance level 1: gpu 450MHz/shader 900MHz/memory 602MHz/1.32V/100%
VID mask: 3
Voltage level 0: 1.15V, VID: 0
Voltage level 1: 1.20V, VID: 1
Voltage level 2: 1.25V, VID: 2
Voltage level 3: 1.32V, VID: 3