Introduction
Programs such as DVDDecrypter, Smartripper, DVDShrink, etc. rely
on a fast, efficient computer system for rapid copying. Transcoding
(shrinking) depends upon the speed of the CPU, memory and motherboard,
in particular. But all programs depend upon the speed of the DVD-ROM
drive. The speed of the DVD-ROM reader can make a tremendous difference
in terms of the total time
required. For example, in my tests, I have seen the same 16X DVD-ROM
drive rip a new 4.7 Gigabyte single layer commercial DVD-Video in
seven minutes in one configuration and in over one hour in another.
There are a number of people in the Forums who have complained that
their system once ripped quickly and now, for some reason, runs
at a snail’s pace. No amount of tweaking the BIOS or Windows seems
to help.
I have done some research
and experimentation using different drives and computers to determine
what can be done to expedite this process. It is also important
to remember that the speed of the DVD-ROM drive can also affect
the quality of your DVD Video playback. This is particularly true
on a slower machine, since software playback is hardware dependent.
Background
The speed of a one time (1X) CDROM is 150
Kilobytes per second and the speed of 1X DVD-ROM is nine times
faster at 1.32 Mbytes/sec. The rotation speed for a DVD drive
is not much faster than a CD-ROM drive but the data acquisition
speed is much faster due to smaller tracks and tighter spacing
of the data tracks. Most drives also include RAM buffers to allow burst rates of
about 12 Mbytes/sec. Programs such as DVDDecrypter also provide
main computer memory buffers. You can observe these buffers fill
and empty during ripping in this program.
Current DVD-ROM readers
cost about $70-$100 US retail (for an IDE drive) and provide read
rates which are typically 8 to 16X for DVD-ROM read. Some units
actually specify that DVD-ROM speed is 16X while DVD-Video is
8X and DVD-R or CD-ROM yet a different speed. Some are honest
enough to confess that these speeds are only realistic when connected
to an IDE Drive
at ATA100 or faster. I have not seen any significant troubleshooting
information in the sparse literature accompanying these drives.
DVD Burners have made
progress in terms of their abilities to read quickly. They were
formerly considered relatively slow
but
the new Pioneer DVR-106 and others read at a very respectable speed. The overriding
question becomes: why wear out your expensive DVD-burner motor
and lasers when you can own a second, read-only drive for a relatively
low price?
DVD-ROM drives and
burners can be connected using IDE connectors, SCSI, USB 2.0 or
Firewire (1394). Consumer SCSI drives do not generally read over
10X rate.
Transfer f data from the hard drive or any CD-ROM
or DVD-ROM
can be performed using IDE slots on the motherboard.
This is the method which is most
often used due to simplicity and cost. Many new computers are
equipped with either DVD-ROM readers (which also read CD-ROM)
or a “combo” drive that reads DVD-ROM and reads, as well as burns,
CD-ROM.
The transfer from the IDE drive
to the CPU and memory can be performed wither with Programmed
Input-Output (PIO)
or with
Ultra Direct Memory Transfer (UDMA). Some BIOS’s allow you to
monitor and change the PIO status of your drives.
A PIO mode 6 is the maximum that
I have seen and may only apply to one drive. This is usually IDE
0 (the master) on the Primary IDE controller or C Drive. This
setting may be ignored by Windows which determines its own “optimal”
setting depending on the motherboard and version of Windows.
The other, preferred
method of transfer is using UDMA. The UDMA controller is integrated
into the motherboard and PCI controller system.
It provides for direct transfer of data from the drive
to main computer memory under instructions from the CPU (central
processing unit). PIO
requires much more CPU activity so that UDMA is much faster, on
the order of 7 to 10 times, depending on the UDMA mode and the
number of drives present. Sharing of UDMA channels does occur
but it depends upon the motherboard and other factors. Certainly
installing your motherboard chipset drivers will help maximize
transfer rate.
I also should point
out that Windows behavior with the same hardware is unpredictable.
One day the drive may run at 7X and the next day, 2.0 times. I
used a 16X DVD-ROM drive for months at 7.0X but after a necessary
Windows 200 installation , the rate dropped to 2.0 times and could
not be adjusted, regardless of its position in the IDE system or tweaking .
You can and should
examine the UDMA status of your drives. It is simple under Windows
2000 and XP. Open Control Panel=>
System=>Hardware=> Device
Manager=>Click on IDE ATA/ATAPI controllers (Figure 1, Win2k) then right click on each Channel
(Figure 2, Win2k) to examine
the DMA status. Choose the tab for Advanced Settings. These examples
are from a two year old motherboard. Current systems will show
a UDMA setting of Mode 4 or 5 for the Primary Master (Drive 0)
and Mode 2 for the Secondary Master (Drive 0) which is frequently
where the DVD-ROM drive is installed. The Primary Slave can be
faster but the Secondary IDE Slave is usually the slowest position.
I recently examined
two name brand Pentium 4 2.5 Gigahertz machines. The DVD-ROM drives
showed only UDMA 2 and performed at only 3.5X with a new 4.7 Gigabyte
drive! The C drives were at UDMA mode 5. You cannot, however,
install a DVD-ROM as Primary Master or the operating system will
not start!
Windows 9.x gives
only the option of right clicking on your CDROM drive in Device
Manager. You can choose DMA and reboot, which is usually a good
idea. DMA can cause problems with hard drives in Windows 9.x.
Speed Data
Both DVDDecrypter
and Smartripper will give you a real time monitor of ripping rate.
I prefer the former program because its data is a little more
complete. Although these programs remove Macrovision and deencrypt,
most of their function is dedicated towards copying the large
VOB files (or an ISO file) to the hard drive. Since most current
hard drives are ATA100 and up and DVD-ROM operates at a maximum
of ATA33, the hard drive should not be a
limiting step. We will address the bottle neck in the next section.
In my tests, I used
various DVD-ROM drives, all advertised as 16X. For a commercial
DVD-Video of 4.7 Gigabyte maximum capacity (2 hours playing time),
the average read rate was 5.0 to 8.0X overall and 13X maximum
when properly configured. The same drive, when poorly configured,
ran at 0.7 to 1.0 time. These discs are single layer and use parallel
track paths (a non-continuous ring)
For a commercial 9.4
Gigabyte disc, the average rates varied between 3.0 and 5.5 X.
These are dual-layer discs that use Opposite Track Paths.
These means that the reader reads one layer from inside to outside
and then the second layer is read outside to inside. On a double
sided disc, one side may be widescreen and contain special features
and is therefore more than 4.7 Gigabytes. This would be the dual-layer
side and often has a gold tint. The other, more silver colored
side, may represent the film in standard aspect ratio and is
less than 4.7 Gig. Only once have I seen a double dual layered
disc.
For DVD-R, high quality,
the average rate was between 2.0 and 5.5 X.
These differences
are explained by a number of factors. First of all, no disc drive
reads at a constant rate and they do not ramp up to maximum rate
immediately. There is an error checking mechanism present and
scratched or worn discs will produce more errors. This does not
mean that the software will halt since some errors will always
be present but perhaps not viewable. Minor errors will, however,
slow the drive—sometimes drastically. Severe, unreadable sections
of the disc will cause your software to halt. You will also notice in DVDDecrypter that
the drive slows down when moving to the next VOB file—this is
due to the need to reapply the CSS crack. In addition, all files
are not burned to the disc in the most efficient manner. The read
head may need to search the DVD-ROM for the proper files.
Commercial DVD’s are
produced using laser etching of a metallic master. Subsequent
copies are then stamped. DVD-R or +R
are
produced using a dye which is sensitive to exposure with a laser.
The quality of the media and methodology is also responsible
for
the differences in speed. In other words, the DVD-ROM will not
read any faster than the speed at which it can reliably extract
the data.
Since the disc read
rate is not constant, I can also rely
upon the total time to copy as an index of speed. This information
is very interesting from the standpoint of the meaning of TIMES.
Does one time mean that this is the minimum required for smooth
viewing of a DVD? At one point, I had an external drive
connected as USB 1.1 to a fast laptop. The movie was certainly
watchable but there were some rough spots. The read rate was
reported at 0.7 times!
Smooth playback is dependent
upon hardware only in a set top box and upon multiple factors
in a PC. These include software, the DVD drive, its
connection to the system, the CPU speed, memory, motherboard and
video card. This is why WinDVD warns
you that software playback is hardware dependent when it first
opens. Most DVD drives operate at 1.2 to 2.0 speed
under worst connection conditions and therefore can read faster
than the PC requires to display the video.
If
you can rip a two hours (120 minute) movie in seven minutes or
less. does that mean that the
read rate is 17 times
(i.e. 120 divided by 7)? DVDDecrypter and Smartripper will report
this rate as 7X during ripping. Perhaps this is what is meant
by the manufacturers when they advertise this merchandise as 16X.
More likely, it refers to maximum possible read rate.
DVDShrink indicates
the data rate during deep analysis. During one session, the rate
was s reported at 3.8 Mbytes/sec. Therefore, the DVD drive must
read at least 3X to avoid a delay in the remainder of the system.
The analysis and shrinking process must involve numerous mathematical
operations since this rate would not be limited by the hard drive.
The Solutions
It should be obvious that connecting your new DVD-ROM
drive anywhere in the IDE chain can slow it down. You burner is
another issue. If your burn at 1X or 2X,
and the burning process progresses smoothly, there is no reason
to relocate it from its current position on the IDE bus.
SCSI DVD readers are
somewhat more expensive and may only give 10X maximum speed—check
the documentation that comes with it.
There
are two methods that will improve your read speed:
The first is to use
a PCI card IDE controller. These controllers are marketed by a
variety of companies. The most famous has the brand name Promise
but Best Buy sells the SIIG brand for about $40 US. Since these
controllers plug directly into the PCI bus, they can deliver UDMA
performance. By setting the DVD-ROM drive to Master, use a separate
IDE port for it on the card. Be certain to purchase an ATA133
card since it will deliver the latest improvements in technology.
The card should include at least one 80 pin high speed IDE cable.
Drivers are provided with the card.
The remaining ports
can be used for other drives if you purchase an additional cable.
If you create a master/slave IDE drive using this port, the UDMA
speeds will be somewhat reduced, as in the main PC IDE port situation.
Install the card and
then its drivers. Check Control Panel to determine the UDMA status
of the card. You can right click on SCSI and RAID controllers
in Device
Manager to
check the DMA status of the new controller card (Figure 3).
Not all card drivers will display the current UDMA status.
Notice that
in this configuration, the 80 pin IDE cable was attached to the
Secondary channel and resulted in UDMA mode 4
. Attaching it to the
Primary channel also gave UDMA
mode 4. This resulted in a read rate of about 13.0X maximum.
The
second method involves using an external DVD player with either
USB 2.0 or Firewire (1394)
inputs to the PC. There are many commercial
external
drive products available for either DVD-ROM or DVD burning. You can simply
search the Net for USB 2.0 or 1394 DVD to find them.
Instead, I chose an external
enclosure (about $70) for USB 2.0
and installed the new 16X DVD-ROM inside it . This particular
unit had its own small power supply with mini cooling fan to supply
the circuit board . The drive was about an eighth of an inch (3mm) too
long for the enclosure which was not a problem. The enclosure
has IDE and power connections internally and a standard 110 volt
connector and USB jack externally. .
My laptop had onboard
USB 2.0 connectors and I purchased a
$20 card USB 2.0 card for the PC. In both cases,
drivers were required for the USB 2.0 serial hub as well as the
host controllers. The external enclosure box included drivers
and the PC card drivers were specific to the NEC controller on
the card.
First the computer is booted
fully and the USB cable from the drive inserted. The first driver
is then loaded. After reboot, examine Device Manager
for
question marks indicating uninstalled drivers. Right click to
open Properties and install the missing driver from the CDROM
or Windows Update. This
process
can be frustrating but it is ultimately successful . If Windows Explorer cannot recognize
your DVD title, it is most likely a driver issue. Since you no
longer
need
the USB 1.1 sockets, you can save an IRQ by disabling this port
in your BIOS settings.
Before removing power
from the drive, it must be “stopped”
by clicking on an icon on the taskbar and then choosing
STOP. Otherwise, Windows can become unstable
and the drivers may need reinstallation .
If Windows locks during ripping, however, removing power to the
drive will allow you to Shut Down peacefully.
The speed
results for the same drive using an internal IDE card and
external USB 2.0 connection were essentially the same—both provided
no restriction in transfer rate from the drive. There was one
small issue with DVDDecrypter on the laptop using the external
drive: it would rip
in ISO mode (up to 13X!) but not in File mode. All other ripping
programs behaved normally and there was no such anomaly with the
external drive on the PC. Playback was also very smooth with the
external drive and it saved wear on the expensive laptop combo
drive.
Many retailers sell
USB 2.0 and Firewire enclosures including enclosures with both
outputs. One of many is http://www.meritline.com/
The maximum USB 2.0 transfer
rate is 60 Mbytes/sec and for Firewire (1394), 50 Mbytes/sec.
The USB 1.1 rate is 1.5 MBytes/sec.
Conclusions
The DVD read drive is the “front end” of the backup system. Even
with a very fast, current system, there can be a significant restriction
in ripping or shrinking speed due to inefficient
transfer of data from this drive.
Here are some suggestions:
- Test
your current DVD ripping speed using DVDDecrypter or other ripping
programs. Install your motherboard’s chipset drivers.
- For
DVD backup, Purchase a separate, dedicated DVD-ROM drive with
16X speed, unless SCSI is used or you choose an integrated,
external USB 2.0 or Firewire drive.
- If you purchase a combo drive, find one with
high DVD read rate.
- Consider using a PCI controller for an IDE
DVD reader with one port dedicated to the reader.
- An external enclosure for an IDE drive can
be used and provides USB 2.0, Firewire, or both inputs to a
PC or laptop.
- Ripping speed depends on the media as well
as the presence of scratches and wear. Transfer rate is highest
with a new commercial,
single layer 4.7 Gigabyte disc and an optimized reader.
