| Ultra ATA Frequently Asked Questions
What are the Ultra
ATA buzz words?
Ultra ATA
is based on the technical specification Ultra DMA/33. A joint effort designed by
Intel, Quantum and Seagate to provide the next generation interface for desktop systems.
Direct
Memory Access (DMA) allows a peripheral to directly transfer data
to the system’s memory without control from the system processor. DMA increases speed
by using the DMA controller to manager the data transfer rather than the processor. The
operating system must have a DMA capable driver installed before DMA can be used.
Bus
Mastering DMA allows the interface card, or drive controller, to manage the
transfer of data from the drive directly to the system’s memory. The motherboard
makers supply the bus mastering drivers that should support DMA control by any bus
mastering compatible interface card.
Ultra DMA
(UDMA) is the latest version of the ATA bus mastering DMA protocol. It increases
the maximum data transfer rate of the ATA bus from 16.6 Mbytes/sec to 33.3 Mbytes/sec. The
ATA/ATAPI 4 specification also introduces error checking, which ensures data integrity at
the higher speeds.
Note: The SCSI
Ultra 2 protocol also uses a new bus mastering DMA protocol sometimes referred to as Ultra
DMA.
What is required to
utilize Ultra ATA?
Each of the following is
required to use Ultra ATA:
- An Ultra ATA compatible
hard drive
- A motherboard with an Ultra
ATA compatible chipset
- OR -
An Ultra ATA compatible add-on controller
- A compatible operating
system
- An Ultra ATA device driver
for the operating system
- A high quality cable
What Seagate drives
are Ultra ATA compatible?
Ultra
ATA functionality was phased in about the time 2-Gbyte drives became
common in new computers. All currently manufactured Seagate ATA drives
support Ultra ATA. For specific drive information, please refer to our
Disc
Drive Encyclopedia.
What Motherboards or
Controller Cards support Ultra ATA?
Ultra ATA compatible
motherboards and controllers were phased in when the Pentium MMX processors were
introduced to the market.
Compatible motherboards
may have one of the following chipsets or a functional equivalent (partial listing):
- Intel Pentium 430TX PCI set
- Intel Pentium Pro 440LX AGP
set
- VIA/AMD: VIA VPX and VP2/97
(also marketed as AMD-640)
- SiS: 5597/98, 5581/82 and
5601
Compatible controllers
(partial listing):
System manufacturers can
help determe if their system supports Ultra ATA. Some common system manufacturers are
listed below.
Which operating
systems support Ultra ATA?
- Most Current
Linux Distributions
Support Ultra ATA. Check the Linux Ultra-DMA Mini-Howto at (http://metalab.unc.edu/LDP/HOWTO/mini/Ultra-DMA.html)
for more information.
- DOS does not support Ultra
ATA.
- Windows 95, Windows NT,
& OS/2 Warp 4.0 all support Ultra ATA when accompanied with current UDMA drivers.
- Windows 98 has Ultra ATA
support integrated into the operating system.
- NetWare does not currently
support Ultra ATA. Contact Novell (www.novell.com) for
more information.
- MacOS does not currently
support Ultra ATA, as no current Apple computers are UDMA compatible. Contact Apple (www.apple.com) for more information.
Where can customers
obtain drivers for their operating system?
Bus mastering drivers may
be obtained from motherboard and chipset makers. Seagate does not offer any bus mastering
drivers.
- Motherboard manufacturers
(partial listing)
- Chipset manufacturers
(these may work on any motherboard with the appropriate chipset)
Is a special cable
required for Ultra ATA?
The Small Form Factor
(SFF) committee has new cable specification for UDMA 33 use, but it is not required. In
some cases, signal noise may prevent a standard cable from allowing a drive to operate at
maximum UDMA transfer rates. The following illustrate some, but not necessarily all,
situations where an SFF specified cable may improve or alleviate performance issues.
If the
standard cable is low-quality, damaged or weakened by many installs.
If the
system has a potential for excessive noise. These systems may have multiple drives, dual
power supplies or an integrated CRT.
If the
system is over-clocked or otherwise configured outside of the manufacturer’s
supported specifications.
For more information on
cables that meet the SFF specification, please contact the following (partial listing):
What issues have been
seen when using Ultra ATA?
Hardware
The VIA VPX and VP2/97
(also marketed as AMD-640) chipsets have demonstrated an issue with some non-Seagate hard
disc drives when operated in Ultra ATA mode. These chipsets can fail to communicate
properly with the drive causing a system hang or lock up. To the best of our knowledge,
this issue does NOT affect Seagate drives. If a Seagate hard drive is suspected of
having this issue, please notify Seagate Technical Support.
It may also help to disable Ultra ATA until the issue can be confirmed.
Software
There are some issues
regarding Microsoft Windows 95, Windows 98 and Ultra ATA support. For detailed
information, contact Microsoft (www.microsoft.com)
for the following documents:
More Information
on Ultra ATA
For additional information
on Ultra ATA, see the following document.
DISCLAIMER:
ALL OTHER COMPANIES, WEB SITES, AND VENDORS MENTIONED IN THIS ARTICLE ARE INDEPENDENT OF
SEAGATE TECHNOLOGY, INC.; SEAGATE MAKES NO WARRANTY, IMPLIED OR OTHERWISE, REGARDING THE
PERFORMANCE OR RELIABILITY OF THESE COMPANIES OR PRODUCTS AND/OR INFORMATION THEY PROVIDE.
THIS INFORMATION IS PROVIDED, AS IS, SOLELY FOR YOUR INFORMATION.
Click here for a Technology Paper on Ultra ATA. |
