I've had this problem ever since I started playing LFS. The sim runs smoothly between 175-300 fps depending on how much stuff is around me. But, even in the least hardware-demanding places, without any other cars, both in single and multiplayer, I get those weird lag spikes which cause the game to freeze for about half a second (duration varies each time) accompanied by a clipping sound. Those occur randomly every 5-30 minutes.

It happens even if I don't have anything else running in the background, with all the unessential services and features disabled.

However, just to check, when I was listening to music off Spotify in the background while playing LFS, the game would freeze like I described, but the music playback would be completely unaffected, so whatever is causing it seems to be affecting LFS specifically, rather than the whole system.

To solve the problem I have already tried:

- Re-installing the system and only installing the essential drivers and LFS to make sure no other application is interfering.
- Cleaning the CPU radiator and putting on fresh thermal paste.
- Putting on fresh thermal paste on the GPU.
- re-flashing the bios and resetting all settings.
- Testing RAM with MemTest86. No errors.
- Overclocking the CPU. This gave two different results as I first used a stock Windows 7 x64 SP1, without any additional updates and it didn't make a difference on it. Then, I installed the same Windows but with all updates. Now, with the overclock, the game stutters so much, it's unplayable. Without the overclock, it's exactly as it used to be before.
- Setting the process priority to high.


My hardware specs are:

Motherboard: Asus M3N-78VM
GFX: Asus GeForce 9800GT (driver version 341.95 - latest recommended)
CPU: AMD Athlon x2 7850 Black Edition (2x 2.8GHz stock)
RAM: 2x 2GB GoodRAM DDR2 CL5
PSU: OCZ 600W
Audio: Asus Xonar DX 7.1
OS: Windows 7 Ultimate SP1 x64


I'm at the end of my wit in trying to solve this problem so I could really appreciate some suggestions