Electronic noise and how it can affect your system

Due to the increased speed, size and quantity of devices in many PCs the system can be very vulnerable to electronic noise on the data lines. This may in fact be the cause of your particular problem. Symptoms of electronic noise can include the following:

  • Slow performance.
  • Drive not detected in BIOS.
  • Drive detected incorrectly in BIOS, with nonsense (garbage) figures (e.g. $0&*?%2).
  • Drive shown on boot up with an engineering name instead of model number (e.g. Millennium).
  • You may receive invalid error codes with the SeaTools diagnostics utility.

In order to overcome problems with electronic noise please try the following:

  1. Make sure the PCI clock speed is not above 33Mhz (this would usually correspond to a 66Mhz Bus speed, or 100Mhz on newer BX chipsets). This is achieved by checking the jumpers on the motherboard. The information on the jumper settings should be explained in the motherboard documentation.
  2. Using a shielded IDE / ATA (40-pin, 80-conductor) cable will most certainly help improve your system’s performance. The secure cable has grounding lines running between the signal lines, which ensure a clearer signal to all devices. You should also attach the master drive to the middle connector on the cable and not the end, so that there is as short a distance as possible between the drive and the motherboard.
  3. One simple way of checking if there are noise issues in your system is to reduce the mode to PIO mode 2 in your BIOS as a test. You should also try disabling the UDMA mode of your BIOS.
  4. In some IBM PCs the hard drive is fixed in the bracket by means of 4 rubber grommets with screws through them so the drive has no hard grounding. This can cause problems with electronic noise but they can be resolved by putting a hard ground fixing into the drive through one of the available top holes. Another possible cause of electronic noise/interference is that on some systems the IDE cable is tucked slightly under the drive (presumably as a cable neatness measure). If the cable is re-routed slightly (no particular direction) from this position it should help but it is important to make sure that the cable does not come loose from the drives or motherboard when you move it.
  5. A power supply fluctuation within the system can also create the same type of symptoms. To try and identify a malfunctioning power connector, make sure the drive is installed alone on a power cable. You should also try connecting the drive to a different power connector.