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DMA Disparity between Optical drives

I have a Dell Dimension 8200 with 2 WD hard drives operating at UDMA 100 and a Plextor DVD-RW (2mb buffer) which is operating at UDMA-4, my 2nd Optical CD-RW drive(8mb buffer) is only operating at UDMA-2....Why??????

All cables are 80 conductor and 18" long

I used the Intel Application Accelerator program to uncover this issue. The reports show both drives with no limit on the transfer mode. Attached are the print out outs showing what is being reported:

Plextor:
Secondary Master: PLEXTOR DVDR PX-800A
Model: PLEXTOR DVDR PX-800A
Firmware: 1.00
Device Type: ATAPI - Removable - CDROM
PIO Mode Support: 0 - 1 - 2 - 3 - 4
DMA SW Mode Support: No Support
DMA MW Mode Support: 0 - 1 - 2
UDMA Mode Support: 0 - 1 - 2 - 3 - 4
Default Transfer Mode: UDMA-4
Current Transfer Mode: UDMA-4
Transfer Mode Limit: No Limit
Cable Type (Device): 80 Conductor
Cable Type (Host): 80 Conductor
PIO PPE: Enabled
UDMA Control Register: Ultra DMA Mode Enabled
UDMA Timing Register: CT = 2 CLK / RP = 8 CLK
Base Clock: Ultra DMA 66 Timings
Auto-Acoustic Management: Feature not supported by device.
Advanced Power Management: Feature not supported by device.

HL-DT-ST

Secondary Slave: HL-DT-ST GCE-8400B
Model: HL-DT-ST GCE-8400B
Firmware: C104
Device Type: ATAPI - Removable - CDROM
PIO Mode Support: 0 - 1 - 2 - 3 - 4
DMA SW Mode Support: No Support
DMA MW Mode Support: 0 - 1 - 2
UDMA Mode Support: 0 - 1 - 2
Default Transfer Mode: UDMA-2
Current Transfer Mode: UDMA-2
Transfer Mode Limit: No Limit
Cable Type (Device): 80 Conductor
Cable Type (Host): 80 Conductor
PIO PPE: Enabled
UDMA Control Register: Ultra DMA Mode Enabled
UDMA Timing Register: CT = 2 CLK / RP = 4 CLK
Base Clock: Ultra DMA 33 Timings
Auto-Acoustic Management: Feature not supported by device.
Advanced Power Management: Feature not supported by device.

Can this CD-RW be improved to UDMA-4? Is the drive limited to UDMA-2 due to its age? Everything else appears to be operating properly.

Gary Case

That's normal ... it's simply as fast as that model drive supports. As long as it's running in DMA mode all is fine => the only thing you need to watch for with optical drives is that they don't revert to PIO mode.

ginovino

ASKER

Then simply put, the CD-rw could never perform at UDMA-4. Its max speed is only UDMA-2 (16mhz ?).
Its a wonderful drive with a built-in 8mb buffer!.. I'd be hard pressed to find one as good. Suggestions?

ASKER CERTIFIED SOLUTION

Gary Case

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