AOpen
CRW4850 IDE CD-RW - Page
1
- Introduction
The CRW4850 is the fastest AOpen recorder that is currently in the market.
We have already (pre)-viewed the CRW5224 that will hit the market soon. The
CRW4850 has been around for quite sometime and supports for the first time the
CAV recording technology. We compare it with other 48X recorders using the latest
firmware and the results are expected to be interesting...
- Specifications
The AOpen CRW4850 supports CAV recording technology for reading/re-writing
and recording. The drive's features as Nero Info Tool reports are:

The drive supports 50X maximum reading / 48X writing and 12X re-writing speeds.
JustLink and JustSpeed technologies are present to prevent the buffer underrun
problems and ensure the burning quality. The cache buffer is 2MB and reading
of CD-Text and CD+G is supported. Nero Info Tool reports that C2 error information
is also supported but its accuracy will be examined later. Lastly the Mt. Rainier
is not present, and probably won't be adopted with any future firmware upgrades...
The following pictures show the drive's supported reading/writing speeds:


As with previous AOpen drives, the default read speed is 40x. Pressing the
Eject button for 5 sec will change the maximum read speed to 50X. At that time
the operation LED will brink 2 times slowly. The drive will keep working at
50X until you reboot your computer.
Below is the Nero Info Tool screenshot with the "Turbo" mode enabled.
The drive's maximum speed is 50X:


- Recording/Re-writing speeds
The AOpen CRW4850 supports 48X with the use of CAV recording technology. Almost
all manufacturers, except from TEAC, utilise the CAV technology for the 48X
recorders. As Nero CD Speed revealed, the drive starts writing at 21.28X and
gradually accelerates ending at the 47.87X speed, giving an average of 36.30X.

When using other CD-R media, the JustSpeed function determines to drop the
recording speed down to 40X. In this mode, the drive uses P-CAV and now the
average writing speed is 31.36X:

- The package
We
got the European retail version that includes: the drive, 48X CD-R media, 12X
HS-RW media, mounting screws, and IDE/Audio cables. The attached software comes
from Ahead (Nero Burning Rom, InCD). A printed manual in two languages that
explains the basic installation and working facts is also bundled.
The drive has been around for a while and can be found in a low price of
less than $60.
Looking at the front panel, we can see the "JustLink/JustSpeed",
"HS-RW" and "AOpen" logos printed on the tray. The eject/next
buttons, volume selector, and the headphone jack are also present, as usual
in the E-IDE models.
The LED blinks differently according to the current operation of the drive.
When you eject/close the disc tray or a disc is accessed, the LED lights to
green. When a disc is just loaded and there is not any other operation, the
light goes out. When audio playback is in progress, the indicator blinks. Inserting
an illegal disc or when some hardware trouble has occurred makes the indicator
blink quickly. Last, while writing a CD the led blinks to orange.
On the rear panel will find the power connector, the IDE cable connector;
the jumpers for setting up the MASTER/SLAVE/CABLE select status and the analogue/SPDIF
connectors. The three jumpers on the right are used to set the drive's ATA working
mode setting. The drive is set to "DMA mode" by default; and you can
set your drive to "UDMA" mode by removing the jumper.
On the top of the drive we can see the model's codename "CRW4850"
among with the manufacturing date:
After removing the screws on the button we can easily see the drive's internal
design (attention this voids your warranty!).
The drive is built on RICOH and ESMT chipsets. The board design is much different
than the CRW5224, making overclocking impossible:
- Installation
The AOpen CRW4850 was installed as a Master in the primary IDE BUS. The drive
worked in UDMA-33 mode. After booting, it identified itself as an "AOPEN
CD-RW CRW4850". We used Nero v5.5.9.17, CloneCD v4.0.1.10 and Ahead
InCD v3.51.61 for the recording tests. Within Nero, under drive properties you
can disable "JustSpeed" to obtain the maximum burning speed (48X)
with all the inserted CD-R media.
The drive came with v1.01 firmware revision installed, but we used the newer
v1.02 and v1.04 to complete the tests and of course revise them. With the latest
firmware there are still few problems with specific CD-R media that are explained
in our "writing quality" page.