3 - Another Try...

void PerformSieve2(unsigned char *array,int limit)
{
  // define variables outside of loops, including precalc loop limit
  int calculatedLimit=limit/3, i=0, k=0, byte=0, bit=0;
  for ( i=3;i<calculatedLimit;i+=2) // skip even numbers
  {
    for ( k=i+i+i; k<limit; k+=i+i ) // skip every even multiple
    {
      // mark item 'k' as non-prime
      byte=k>>4; // quick way of dividing by 16
      bit=(k>>1)&0x07;
      m_bitArray[byte] |= 1<<bit;
    }
  }
}