Files copied from CDR are transferring too slowly

[wilburpan]

I have a new Samsung CD/DVD drive, and am transferring files that I have burned on CDR's to my hard drive. I'm using Gnome.

The file transfer dialog tells me that I'm getting transfer speed of about 2.5 MB/sec, or about 4 minutes to transfer 600 MB or so. This seems awfully slow to me. I found a reference saying that this is about a 4X transfer rate, although the CD speed is supposed to be 52X.

How can I speed this up?

[jongeek]

Are you using an IDE or a SATA CDROM ? How about your hard drive ?

If IDE, is your CDROM on the same IDE controller as your hard drive ? That can cause significant slowdowns. Are you familiar with hdparm ? Try running that and post the output. That will show if DMA is enabled.

[eccerr0r]

At 52x, with 1x=150kB/sec ==> a theoretical rate of 7.8MB/sec. Compared to 2.5MB/sec it is quite slow but in the ballpark.

However one key thing about CD's is that they're spirally written and depending on where the data is written, the transfer rate can be different. Towards the outside portions of the disc (cd's are written from the inside out) the transfer rate can get higher if the cdrom drive is a CAV-type which most are.

Another issue is that are you copying small files from the CD or large ones? CDs have very slow random access times.

4X CD transfer rate is 600kB/sec. 4X DVD transfer rate is considerably faster, though.

As stated above, you should check to make sure DMA is enabled and you're not sharing a channel too, those can be fairly detrimental to copy speeds as well.

[wilburpan]

Are you using an IDE or a SATA CDROM ? How about your hard drive ?

If IDE, is your CDROM on the same IDE controller as your hard drive ? That can cause significant slowdowns. Are you familiar with hdparm ? Try running that and post the output. That will show if DMA is enabled.

My hard drives are SATA. I think that the optical drive is SATA as well. Here's the hdparm output.

Code: Select all

# hdparm -I /dev/scd0 

/dev/scd0:

ATAPI CD-ROM, with removable media
	Model Number:       TSSTcorpCD/DVDW SH-S183L                
	Serial Number:      
	Firmware Revision:  SB01    
Standards:
	Likely used CD-ROM ATAPI-1
Configuration:
	DRQ response: 50us.
	Packet size: 12 bytes
	cache/buffer size  = unknown
Capabilities:
	LBA, IORDY(can be disabled)
	DMA: mdma0 mdma1 mdma2 udma0 udma1 *udma2 
	     Cycle time: min=120ns recommended=120ns
	PIO: pio0 pio1 pio2 pio3 pio4 
	     Cycle time: no flow control=120ns  IORDY flow control=120ns
Commands/features:
	Enabled	Supported:
	   *	SATA-I signaling speed (1.5Gb/s)
	   *	Host-initiated interface power management
	   *	Phy event counters
	    	Device-initiated interface power management
	   *	Asynchronous notification (eg. media change)
	   *	Software settings preservation

Based on the other comments maybe I'm just expecting too much. Would it be too much to ask for someone to burn a CD with 600MB of mp3 files and report how long it takes it to copy the files to their hard drive?

Also, how do I check for channel sharing?

[eccerr0r]

Okay, now we know you're copying MP3s. This can be slow as you're dealing with many small files. Do you hear the drive seeking - making head movement noises? Each time it moves the head it cannot read the disk at the same time, leading to loss in throughput.

The fastest way to read the whole disk, usually, is to copy an image of the CD, sequentially, then copy the files off of the image file. That way you deal with hard drive seeks in terms of milliseconds instead of cdrom seeks, which can possibly take up to a second to complete.