This is pretty straight-forward. If your motherboard doesn't support your hard disk maximum transfer rate, the disk will be accessed using the chipset's maximum transfer rate - or less, if you don't match the other listed criteria.

A very good example is an ATA-133 hard disk installed on a motherboard based on Intel chipset. Intel does not support the ATA-133 standard, even on their latest chipsets like Intel 915 and 925 series. This means that your hard disk will be accessed at 100 MB/s on these latest chipsets because the chipset doesn't support the ATA-133 standard. Another example: if you install this ATA-133 hard disk on an older motherboard based on the Intel 815 chipset, it will be accessed at 66 MB/s, since this is the chipset maximum transfer rate.

To learn which is the maximum hard disk transfer rate from your motherboard, simply read its manual. This is listed on its main features page. If you don't have your motherboard manual, download it from your motherboard manufacturer website. If you don't know your motherboard manufacturer and model or even don't know which chipset your motherboard uses, run a hardware identification software like Hwinfo, Sandra or Everest (they are all available at our download section). We also have a complete list of all motherboard manufacturers and their websites.

Alternativelly, you can read the chipset specifications - including the maximum transfer rate from its IDE ports - on the chipset manufacturer website. Here are the links to the most common manufacturers:

• ALi
• ATI
• Intel
• NVIDIA
• OPTi
• SiS
• ULi
• Utron
• VIA

If the IDE ports from your motherboard have a maximum transfer rate lower than your hard disk, you can solve this issue by installing an add-in card with IDE ports with higher specification. Two companies that manufacture such boards are HighPoint (http://www.highpoint-tech.com) and Promise (http://www.promise.com). On Figure 3 you can see an add-in card with two ATA-133 ports from Promise.

click to enlarge
Figure 3: PCI add-in card with two ATA-133 ports from Promise.