What texture size, resolution and card do you have?
I did a quick test for me in offline mode (9600GT 512MB, 1280*1024, textures 512), and did try all settings from 3-8 (each time restarting game of course.
The differences in used vid mem were absolute minimal, and I couldn't get over 25% used vid mem.
EDIT: made no difference in online play.
Seems others didn't have any luck with this either. The only other thing that I did was under Video Settings prior to going to the game on the clipboard, I selected the Set Custom Field of View to manual and left the grayed out number as default as the value, ( for me it was 86 ) instead of letting the game automatically set the view. Don't ask me why I did it, I was looking for everything/anything to get the game to play. I have now had over 5 hours of uninterupted game play, no "stutters" or "lock-ups". As for my settings the resolution is 1280 X 1024, and texture size is at 1024 instead of the recommended 512. I have AA at 2X, and all the bells and whistles enabled under the advanced settings. Below is my DXDIAG: Hope this helps.
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System Information
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Time of this report: 7/29/2009, 02:20:28
Machine name: JOE
Operating System: Windows XP Professional (5.1, Build 2600) Service Pack 3 (2600.xpsp_sp3_gdr.090206-1234)
Language: English (Regional Setting: English)
System Manufacturer: To Be Filled By O.E.M.
System Model: To Be Filled By O.E.M.
BIOS: BIOS Date: 05/30/08 14:59:54 Ver: 08.00.15
Processor: AMD Athlon(tm) 64 X2 Dual Core Processor 5600+, MMX, 3DNow (2 CPUs), ~2.9GHz
Memory: 3328MB RAM
Page File: 998MB used, 4212MB available
Windows Dir: C:\WINDOWS
DirectX Version: DirectX 9.0c (4.09.0000.0904)
DX Setup Parameters: Not found
DxDiag Version: 5.03.2600.2180 32bit Unicode
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DxDiag Notes
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DirectX Files Tab: No problems found.
Display Tab 1: No problems found.
Sound Tab 1: No problems found.
Music Tab: No problems found.
Input Tab: No problems found.
Network Tab: No problems found.
--------------------
DirectX Debug Levels
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Direct3D: 0/4 (n/a)
DirectDraw: 0/4 (retail)
DirectInput: 0/5 (n/a)
DirectMusic: 0/5 (n/a)
DirectPlay: 0/9 (retail)
DirectSound: 0/5 (retail)
DirectShow: 0/6 (retail)
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Display Devices
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Card name: NVIDIA GeForce 9800 GTX/9800 GTX+
Manufacturer: NVIDIA
Chip type: GeForce 9800 GTX/9800 GTX+
DAC type: Integrated RAMDAC
Device Key: Enum\PCI\VEN_10DE&DEV_0612&SUBSYS_08A219F1&REV_A2
Display Memory: 512.0 MB
Current Mode: 1280 x 1024 (32 bit) (75Hz)
Monitor: Plug and Play Monitor
Monitor Max Res: 1600,1200
Driver Name: nv4_disp.dll
Driver Version: 6.14.0011.9038 (English)
DDI Version: 9 (or higher)
Driver Attributes: Final Retail
Driver Date/Size: 7/14/2009 13:54:00, 5842816 bytes
WHQL Logo'd: Yes
WHQL Date Stamp: n/a
VDD: n/a
Mini VDD: nv4_mini.sys
Mini VDD Date: 7/14/2009 13:54:00, 7741664 bytes
Device Identifier: {D7B71E3E-4552-11CF-0F59-A92803C2CB35}
Vendor ID: 0x10DE
Device ID: 0x0612
SubSys ID: 0x08A219F1
Revision ID: 0x00A2
Revision ID: 0x00A2
Video Accel: ModeMPEG2_C ModeMPEG2_D
