AMD HD6850 mining speed is very slow According to litecoin.info/Mining_Hardware_Comparison,
6850 is 200+kH/s
But I run speed is 17.28K/14.39Kh/s, what's wrong??

 cgminer version 3.5.0 - Started: [2013-11-30 17:08:22]
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 (5s):17.25K (avg):14.28Kh/s | A:0  R:0  HW:0  WU:12.4/m
 ST: 2  SS: 0  NB: 6  LW: 45  GF: 0  RF: 0
 Connected to coinotron.com diff 256 with stratum as user xxxxx
 Block: fa394c9dc29d9325...  Diff:99.8M  Started: [17:15:04]  Best share: 107
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 [P]ool management [G]PU management [S]ettings [D]isplay options [Q]uit
 GPU 0:  58.0C 1206RPM | 17.28K/14.39Kh/s | A:0 R:0 HW:0 WU:12.4/m I: 8
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GPU 0: 16.9 / 12.4 Kh/s | A:0  R:0  HW:0  U:0.00/m  I:8
57.0 C  F: 37% (1148 RPM)  E: 775 MHz  M: 1000 Mhz  V: 1.150V  A: 96%  P: 0%
Last initialised: [2013-11-30 17:08:36]
Intensity: Dynamic (only one thread in use)
Thread 0: 17.2 Kh/s Enabled ALIVE
Your intensity is very low (I:8) - dynamic intensity does not work well with scrypt. You will need to increase it manually. You can set a value to use when starting the program by adding --intensity 13 to your command line options/batch file. Replace the number 13 with the desired intensity. For a HD6850, I suggest you try values from 10 to 15. 

If increasing the value by one notch does not significantly raise kh/s, gives you hardware errors (the number after HW:) or starts impacting in a noticeable way on desktop performance, then reduce it again.

You can also change the intensity whilst cgminer is running. Press g, then i, then carefully type the number, then enter.