Hi,
i just bought an ATI msi 7950 3gb OC edition, but i'm very disappointed about its hashrate. I red that whit that card i can reach 600 or even more kh/s, but i barely reach 400kh/s, and, most important, i still don't know why!!

My frequency:
gpu clock @880mhz
memory clock @1250mhz
temp @70°

I tried whit:
-different version of cgminer (3.6.2, 3.7.0, 3.7.2), without changes
-different version of catalyst (13.1, 13.9, 13.12), without changes.
-different setting. I tried more or less every setting suggest in https://litecoin.info/Mining_hardware_comparison.
 I noticed that:
 -i can't set intensity greater than 13. With 13 i haven't any hw error, with 14 or more, i have too much hw error.
 -i can't set thread concurrency greater than 8192. If i use greater value i have this error--->
maximum buffer memory device 0 supports says 536870912
your script setting come to 939524096
error -61 etc
failed to init GPU thread 0 disagling device 0

now i'm using this settings --gpu-threads 2 --thread-concurrency 8192 -I 13
                                       setx gpu_use_sync_objects 1
                                       setx gpu_max_alloc_percent 100

any help??