My system specs are
AMD phoenom x2 550 3.50ghz
4gb platinum 1066 ddr2 ram
bfg geforce 9800gt oc
stock cooler's except i have my old athlon 64 x2 4800 fan attached to my video card along with the stock one. keeps it about 10c degrees cooler
not sure if this works just for my setup but i did the normal config changes stall cru_1 and changed the first 2 threads to 2 and 2. i got a boost in fps but it still kinda had this stutter to it so i spent a few hours mesing with the config and i found that changing the main logical thread got rid of almost all stuttering and gameplay is as smooth as ive seen. i changed the main logical thread to 0 from 1. so if this helps you out awesome. it made a playable game into a great looking playable game!
VIDEOSETTING_ADAPTERINDEX = 0
VIDEOSETTING_WIDTH = 1680
VIDEOSETTING_HEIGHT = 1050
VIDEOSETTING_COLORDEPTH = 32
VIDEOSETTING_VSYNC = 1
VIDEOSETTING_REFRESHRATE = 59
VIDEOSETTING_WINDOWMODE = 0
VIDEOSETTING_MSAA = 4
VIDEOSETTING_MSAAQUALITY = 7
VIDEOSETTING_MAXTEXTURESIZE = 4096
VIDEOSETTING_DEPTHOFFIELD = 0
VIDEOSETTING_FLOORREFLECTION = 0
VIDEOSETTING_PLAYERLOD = 0
VIDEOSETTING_STADIUMLOD = 1
VIDEOSETTING_CROWDDETAIL = 1
VIDEOSETTING_SHADERDETAIL = 1
VIDEOSETTING_SIDELINECHARACTER = 1
VIDEOSETTING_ANISOTROPICQUALITY = 2
VIDEOSETTING_PARTICLEFFECT = 0
VIDEOSETTING_FORCE_HDR_ON_INTEL_GPU = 0
MAIN_LOGICAL_THREAD = 0
GPU_LOGICAL_THREAD = 0
STALL_CPU_ON_END_FRAME = 1
LIMIT_FLIP_QUEUE_LENGTH = 2
LIMIT_FLIP_QUEUE_LENGTH_SLEEP = 0
STICKYKEY = 510
TOGGLEKEY = 62
FILTERKEY = 126
ACCESSIBILITYKEY_SAVED = 1
LANGUAGE = -482460772
WINDOW_X = 0
WINDOW_Y = 0
CLOTH_LOGICAL_THREAD_0 = 2
CLOTH_LOGICAL_THREAD_1 = 2
CLOTH_LOGICAL_THREAD_2 = -1
CLOTH_LOGICAL_THREAD_3 = -1
NETWORK_PERFORM_BENCHMARKING = 1
NETWORK_OPT_UPSTREAM_BANDWIDTH = 604997
ONLINE_FORWARDED_PORT = 0