Installing both a CD and a CD R/W

[Stu Wright]

Should both drives be connected to the Secondary IDE or the CD R/W as the master on the Secondary IDE and the CD as slave on the Primary IDE?
What's the best arrangement?

[Kurylo]

I have exactly what you've said. And nothing bad happens. Here:
PM: HDD, PS: none;
SM: CD-RW, SS: CD-ROM.

[Psycho Logical]

It really depends on how you want to burn.

1. CD-ROM drive direct to CD-RW. or
2. CD-ROM drive to HDD to CD-RW

If #1, you can't have both drives on the same IDE channel, regardless which is master or slave.

• PRIMARY IDE: Master - Boot HDD / Slave - CD-ROM drive
• SECONDARY IDE: Master - CD-RW

If #2, you should have the CD-ROM drive on a separate channel from the HDD.

• PRIMARY IDE: Master - Boot HDD
• SECONDARY IDE: Master - CD-RW / Slave - CD-ROM drive

[arthur888]

Quote-----

If #1, you can't have both drives on the same IDE channel, regardless which is master or slave.

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It is possible to use this configuration, even when copying directly from cd to cdrw, but I agree it is a little more likely to give problems.

Generally the source and destination drives should be on different channels.

[Kurylo]

Maybe, I'm wrong, but check this:
UDMA33 is 33MBpS. All contemporary CD-RWs and CD-ROMs support UDMA33. If you use them simultaneously on the one shannel, then this speed is divided by 2: 16.67MBps for CD-RW and 16.67MBpS for CD-ROM. But as fas as even up-to-date CD-ROMs and CD-RWs even read data (not saving it) with maximum nearly 52x, then the maximum reachable by such driver speed is 7.8MBpS. So, here we have a reserve of 16.6-7.8=8.8MBpS for each drive. So, they will not disturb one another up to the 110x speeds...

[arthur888]

It's not only the transfer rate that counts. It's also atapi commands that have to be sent and this is done more efficient when the drives are on different channels. For the transfer rate you're right, that should not be a problem for even the newest drives.

[vibe666]

the whole point of having the CDROM and CD-RW on different channels is that the system can't read continuously from one drive whilst writing to the other on the same channel.

if they are on different channels, then no problem.

having the CDROM as the primary slave won't cause any real problems because reading from CDROM and writing straight to HD will never be as time critical as burning CD's on the fly.

same goes for having the CD RW on the same channel as the HD. reading from one and writing to the othercan't be constant. if your CDRW has a big buffer then this usually won't be a problem as most hard disks can take up the slack but why take the risk?

PM: HD
PS: CDROM
SM: CDRW
SS: ZIP, HD, Tape etc.

[Kurylo]

But what are the internal buffers made for? They allow to write CD-RWs data from buffer while CD-ROM reads another portion of it.

[arthur888]

That's right, and theoretically it should give no problem with both drives on the same channel, but sometimes the buffer is not large enough, for example when a piece of the source disc has a little damage so it has to be read more than one time. If the drives were on different channels the system could continue writing to the cdrw from the software buffer in RAM while attempting to read the source drive. If both drives are on the same channel the cdrw can only empty its buffer and stop burning. When there are 2 drives on one channel there can only one drive be using the IDE controller at a time.

BTW: Are we talking about a new burner with anti-coaster technology here? If so, it doesn't matter in what position the drive is placed.

[Psycho Logical]

Let's not forget that the speeds claimed for CD-ROM and CR-RW drives are theoretical maximums.

If you do achieve the read speeds claimed, it is only at the outer tracks,
and it is not constant over the entire data area.

Until you verify the specs and whether the drive uses CAV or CLV, I don't think you can justify a
blanket statement like "All contemporary CD-RWs and CD-ROMs support UDMA33."
There are still plenty of new low-end drives sold that only support PIO modes, not UDMA.

Regardless of any "Burn-Proof" feature, you can not get simultaneous access to two drives on the
same IDE channel as master or slave. Switching between drives is not instantaneous -- it requires the
CPU/chipset to process an interrupt, which requires a finite amount of time.

For Burn-Proof to be 100% effective, it has to become the over-riding factor, and it may sometimes
have to reduce the speed of the write operation to accomplish this.

[vibe666]

and not forgetting that Burn-Proof™ is a safety feature.

sure it works. i've tried it. Ctrl+Alt+Del mid-write for a good 30 seconds and it still kept chugging along when i returned to windows.

but it's like saying I've got a Volvo it has all these safety features, it doesn't matter if I hit stuff I'll be OK.

I'm told you can leave a Burn-Proof™ writer frozen all day and it will still continue where it left off afterwards.

but do you really want to overwork it?

[arthur888]

Quote-----

Regardless of any "Burn-Proof" feature, you can not get simultaneous access to two drives on the
same IDE channel as master or slave.

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I'm sorry if I didn't exactly make clear what I meant :( . I didn't say that with burn proof it would be possible to access two drives simultaniously. I was talking about the risk of buffer underruns when connecting source and cdrw on the same channel. This risk would not apply if the burner had a buffer underrun protection, such as burn proof. Ofcourse it would still be recommended to use the best settings but if something goes wrong you don't have to worry about your CD being messed up.

Best regards,

Arthur

[Kurylo]

That's theory. I have both CD-RW (16/10/40) and CD-ROM (40) at one IDE channel. And no any mistake since I've brought them together. That's practice.

[arthur888]

It's not that it's impossible, but if you do have problems it's recommended to use the optimal settings.