I'm having a stuttering issue with FO3 GOTY Edition purchased via Steam. I've seen discussions of microstuttering vs "regular" stuttering and I believe I'm experiencing something other than microstuttering (based on a few Youtube videos). Basically my game locks up periodically for a second or two at a time. The sound is still going (radio, ambient, etc), but video and controls are frozen. This happens both indoors and outdoors in different places of the world. I am not 100% sure of this, aggroing a mob seems to trigger this for me. A pretty consistent way that I'm able to reproduce this at the moment, for example, is to travel to an area with fire ants. As soon as one becomes aware of me and starts charging towards me, the game will lock up briefly. It will continue doing so as the fight goes on. I believe occasionally this happens outside of fighting as well, but it's most frequent while engaging an enemy (and obviously most untimely in this case).

Things that I've tried:

- Turning down video game settings below what is auto-detected
- Turning down resolution
- Turning off vsync
- Turning off water effects
- Turning off various sound settings (radio, footsteps, effects, etc)
- Running windowed
- Tweaking fallout.ini for bUseThreadedAI=1 and iNumHWThreads=2
- Tweaking fallout.ini for iFPSClamp
- Using Large adress aware enabler linked to from other threads on this forum
- Using SFR (via FOSE) plugin

General computer things:
- Fully patched FO3 via steam
- Fully patched Windows 7 64-bit
- Latest drivers, including chipset, sound, video.
- Fully defragmented hard drive ( striped raid), checked for sector errors and start errors
- Memtest tested RAM
- Shutting down everything short of AV (AVG)
- No apparent CPU / GPU overheating issues

It makes for quite frustrating game experience. I haven't had this issue with other games I've tried, most recently Borderlands and The Witcher 2. I see other people discuss this problem in other threads and elsewhere on the web, but there doesn't seem to be a definitive fix and none of the suggestions I've seen have fixed it for me. What else can I try?

DxDiag snippets:

------------------System Information------------------Time of this report: 9/21/2011, 23:04:02       Machine name: FATTY   Operating System: Windows 7 Ultimate 64-bit (6.1, Build 7601) Service Pack 1 (7601.win7sp1_gdr.110622-1506)           Language: English (Regional Setting: English)System Manufacturer: Gigabyte Technology Co., Ltd.       System Model: EX58-UD4P               BIOS: Award Modular BIOS v6.00PG          Processor: Intel(R) Core(TM) i7 CPU         920  @ 2.67GHz (8 CPUs), ~2.7GHz             Memory: 6144MB RAMAvailable OS Memory: 6142MB RAM          Page File: 3751MB used, 8531MB available        Windows Dir: C:\Windows    DirectX Version: DirectX 11DX Setup Parameters: Not found   User DPI Setting: Using System DPI System DPI Setting: 96 DPI (100 percent)    DWM DPI Scaling: Disabled     DxDiag Version: 6.01.7601.17514 32bit Unicode---------------Display Devices---------------          Card name: NVIDIA GeForce GTX 275       Manufacturer: NVIDIA          Chip type: GeForce GTX 275           DAC type: Integrated RAMDAC         Device Key: Enum\PCI\VEN_10DE&DEV_05E6&SUBSYS_11713842&REV_A1     Display Memory: 3688 MB   Dedicated Memory: 873 MB      Shared Memory: 2815 MB       Current Mode: 1680 x 1050 (32 bit) (59Hz)       Monitor Name: DELL E2209W(Digital)      Monitor Model: DELL E2209W         Monitor Id: DELD01F        Native Mode: 1680 x 1050(p) (59.954Hz)        Output Type: DVI        Driver Name: nvd3dumx.dll,nvwgf2umx.dll,nvwgf2umx.dll,nvd3dum,nvwgf2um,nvwgf2umDriver File Version: 8.17.0012.8026 (English)     Driver Version: 8.17.12.8026        DDI Version: 10       Driver Model: WDDM 1.1  Driver Attributes: Final Retail   Driver Date/Size: 8/3/2011 04:50:00, 15064168 bytes        WHQL Logo'd: Yes    WHQL Date Stamp:   Device Identifier: {D7B71E3E-46A6-11CF-A844-7D311FC2C535}          Vendor ID: 0x10DE          Device ID: 0x05E6          SubSys ID: 0x11713842        Revision ID: 0x00A1 Driver Strong Name: oem11.inf:NVIDIA_SetA_Devices.NTamd64.6.1:Section005:8.17.12.8026:pci\ven_10de&dev_05e6     Rank Of Driver: 00E62001        Video Accel: ModeMPEG2_A ModeMPEG2_C ModeVC1_C ModeWMV9_C -------------Sound Devices-------------            Description: Speakers (Realtek High Definition Audio) Default Sound Playback: Yes Default Voice Playback: Yes            Hardware ID: HDAUDIO\FUNC_01&VEN_10EC&DEV_0885&SUBSYS_1458A002&REV_1001        Manufacturer ID: 1             Product ID: 100                   Type: WDM            Driver Name: RTKVHD64.sys         Driver Version: 6.00.0001.6449 (English)      Driver Attributes: Final Retail            WHQL Logo'd: Yes          Date and Size: 8/30/2011 17:28:46, 3069032 bytes            Other Files:         Driver Provider: Realtek Semiconductor Corp.         HW Accel Level: Basic              Cap Flags: 0xF1F    Min/Max Sample Rate: 100, 200000Static/Strm HW Mix Bufs: 1, 0 Static/Strm HW 3D Bufs: 0, 0              HW Memory: 0       Voice Management: No EAX(tm) 2.0 Listen/Src: No, No   I3DL2(tm) Listen/Src: No, NoSensaura(tm) ZoomFX(tm): No            Description: Realtek Digital Output (Realtek High Definition Audio) Default Sound Playback: No Default Voice Playback: No            Hardware ID: HDAUDIO\FUNC_01&VEN_10EC&DEV_0885&SUBSYS_1458A002&REV_1001        Manufacturer ID: 1             Product ID: 100                   Type: WDM            Driver Name: RTKVHD64.sys         Driver Version: 6.00.0001.6449 (English)      Driver Attributes: Final Retail            WHQL Logo'd: Yes          Date and Size: 8/30/2011 17:28:46, 3069032 bytes            Other Files:         Driver Provider: Realtek Semiconductor Corp.         HW Accel Level: Basic              Cap Flags: 0xF1F    Min/Max Sample Rate: 100, 200000Static/Strm HW Mix Bufs: 1, 0 Static/Strm HW 3D Bufs: 0, 0              HW Memory: 0       Voice Management: No EAX(tm) 2.0 Listen/Src: No, No   I3DL2(tm) Listen/Src: No, NoSensaura(tm) ZoomFX(tm): No