The requirements for use of an Ultra ATA/100 Hard Drive are:

Ultra DMA (80-Conductor) IDE/ATA Cables

Q: How can I tell if I have a 40-pin, 80-conductor cable?
A: Short answer: you just have to eyeball it.

"40-pin" means it will have 40 connector holes on the connector ends of the cable.
"80-conductor" means that the cable has 80 thin wires (as opposed to the older 40-wire cables).

A standard 80-conductor Ultra DMA IDE/ATA interface cable.
Note the blue, gray and black connectors, and the 80 thin wires.
The red marking on wire #1 is still present (but hard to see in this photo.)

Generally, you can tell the new 80-conductor IDE cables from the older IDE cables or SCSI cables because the newer cables are supposed to use the following color coding:

Blue: The blue connector attaches to the host (motherboard or controller).
Gray: The gray connector is in the middle of the cable, and goes to any slave (device 1) drive if present on the channel.
Black: The black connector is at the opposite end from the host connector and goes to the master drive (device 0), or a single drive if only one is used.

Color coding of the connectors is used to make it easier to determine which connector goes with each device.

For more details, see the pcworld page on this topic.

Ultra DMA vs Ultra ATA

Ultra-DMA is Ultra-ATA is UDMA (Ultra-DMA = Ultra-ATA = UDMA = Ultra DMA = one kind of IDE)

IDE vs ATA

Integrated Drive Electronics / AT Attachment (IDE/ATA) Interfaces:
The most popular interface used in modern hard disks--by far--is the one most commonly known as IDE.
This interface is also known by a truly staggering variety of other names such as ATA, ATA/ATAPI, EIDE, ATA-2, Fast ATA, ATA-3, Ultra ATA, Ultra DMA and many more as well.
The "proper" name for the IDE interface is AT Attachment, or ATA.
"One of the most common terms used to refer to these new drives was Ultra ATA, which appears to be a combination of the terms "Ultra DMA" and "ATA"."
"Ultra ATA/100 is the marketing term for hard disks that use the new Ultra DMA mode 5, supporting interface transfers at 100 MB/s (technology as of late 2000)."

A controller card or motherboard chipset with Ultra ATA/100 capability

For example, the Dell XPS (v2) uses the Intel 82801EB IDE Controller ("Intel® 82801EB I/O Controller Hub 5 [ICH5]") ,
which is supposed to support both Ultra ATA/100/66/33 (BMIDE and PIO modes) AND Serial ATA (Independent DMA operation on two ports).

Ultra ATA/100 compatible BIOS or driver

The Dell 8200 BIOS supports "IDE Drive UDMA" but it's not clear what level of support is provided.
("Note: In common parlance, drives that use Ultra DMA are often called "Ultra ATA/xx" where "xx" is the speed of the interface.
So, few people really talk about current drives being "Ultra DMA mode 5", they say they are "Ultra ATA/100". ")

The Dell XPS uses ...