Another solution that isn't as "difficult" is to simply run a system cleanup through windows and reinstalling your driver .dll files (graphics card drivers and Pentium4 drivers if your PC requires them) If the P4 driver base is corrupted, a binary 0 can be added which won't interfere with symmetry commands but rather linear thread commands, which would explain the lag. Try reinstalling the motherboard drivers because the memory access chip could very well be writting an additional binary digit into the L2 cache, making the P4 read another digit that shouldn't exist and it has to use error correction which causes those laggy pauses your describing.