Simply because the engineers made the board intended mainly for IDE (aka ATA and PATA) drives. They included a SATA connector in order to not exclude the option for S-ATA (Serial ATA) completely, without the use of a controller card that will take up a PCI slot. Then there is a settin included in the BIOS for the S-ATA which makes it possible to boot from a S-ATA device.
Not all motherboards allows booting from a PCI or PCI-X or PCI-Express connected device.
Hope this helped you.
Regards,
tweak
If it's a SATA connector, in one of the SATA ports. If it's a ribbon cable (commonly called IDE cable, but that's incorrect), into the IDE connector on the Motherboard. (that's properly named)
use a different harddrive not using SATA such as an external USB or IEE1394 or SCSI or replace your motherboard with one with more SATA ports (4 ports is standard minimum)
If there are four connectors, then you are probably referring to Serial ATA (SATA). If the connector is a small, L-shaped socket, then you simply need to get a SATA cable. It is a thin flat cable, almost always red with black connectors at the ends. At least one should have came with the motherboard/case/power supply or hard drive. You can usually use any of the plugs on the motherboard, but look for one that says SATA0 (zero) or SATA1. Just start with the lowest number you can find.
You can only have 1 Sata HDD per Sata connector, however on IDE you can have 2 IDE, 1 set to master the other to Slave or if supported both set to CSS (Cable Select). So you can have 4 Sata HDD and 2 IDE HDD per IDE channel. One thing you need to be aware of is your Power Supply. Make sure it is capable of handling such a load or you will get write errors on the Drives. Hope that helps.
An IDE cable connects a hard drive or CD drive to the main board of the computer.
20 pin P1 connector.
One would use a SATA to IDE adaptor for things such as backing up data, virus scanning and imaging. These adapters can be purchased from places like Best Buy, Tiger Direct, Amazon and eBay.
ATX
There's different types of connections that lead to a hard disk. you'll have to ellaborate your question.But..... I can tell you what the wires are....There's the ribbon cable. (flat and wide cable that connects to the back of your drive to the motherboard)The Molex plug (white and it has four pins) that powers your hard disks, it leads to the power supply.OR... The SATA power connector (which is black, has 5 wires (red, yellow, 2 black, and one orange) which connect to the back of your hard diskThere's also the SATA data transfer cable, it's a thin (usually red) cable that connects to the motherboard to your hard drive. (it's a thin "L" shaped slot)
The only one thing which you can do in such situation is to try updating BIOS. If it didn't help there is nothing what you can do. Sometimes you can purchase so called extension cards. Which for instance allow you to connect SATA interface hard drives to non-SATA motherboards.
The atx 12 connector is one of the motherboard power connectors and used for 12 volt power connect for cpu voltage regulator.
Normally, only one SATA per channel can be hooked up to a motherboard. However, you can buy SATA port multipliers (similar to USB hubs) allowing you to put as many as fifteen devices on a channel. see here: http://www.tomshardware.com/reviews/silicon-image-brings-virtualization-esata,1610-3.html