How to connect 12 DVD-RW drives?

vbimport

#1

I want to connect 12 (PATA) DVD-RW drives to an old computer (linux). At the moment I fitted them in an external enclosure (with two power supplies). The linux computer has to build unique cd-images and burn them to the drives. Each cd will be unique.

I can try to connect everything through an ide-cable, but I don’t think they will be long enough. So I was looking for a solution over USB2/Firewire800.

I found a bridge board Firewire800 to 4x PATA. Probably I will use this as an solution to connect evereything to the computer.[ul]
[li]Is there somebody who has experience with this kind of boards?
[/li][li]Does firewire has enough bandwidth for 12 DVD-burners (18X)?
[/li][li]Has the PCI-interface enough bandwidth to transfer the data to the 12 burners?
[/li][li]What should the speed of the HDD-drive be to generate the images from flat files and burn them?
[/li][*]Can I expect to find other hardware issues?[/ul]I searched the internet and lots of fora. I hope there are some people on this forum with more experience in this area.


#2

If you’re trying to burn 12 unique CDs at once, the issue will not be how or whether you have connected 12 burners, but how will you manage to deliver a data stream to 12 drives at once. It’s likely that you will need 4-6 very fast hard drives and have each one feeding 2-3 burners. And that also assumes that your PCI bus has enough available bandwidth for ALL the burns.

That said, PCI cards will connect 4 drives, but they will share 2 channels, so again you have a bottleneck or 2 added to the picture. You really need a separate IDE channel for each burner.

If you’re talking about burning DVD’s, then all bets are off cause it’s unlikely you will get one HDD to feed more than one burner at speeds over 8x.


#3

If I were you I would just get a “duplicator controller” search ebay. That requires just one HDD.

You should have all ODD drives the same model and latest firmware.


#4

“Duplicators” don’t allow you to burn different images at the same time.


#5

no
no
no
no
yes


#6

[QUOTE=CDan;2000823]“Duplicators” don’t allow you to burn different images at the same time.[/QUOTE]

Yeah, but think about it. If he needs 12 drives to copy stuff, it sounds like he’s doing mas duplication, not two of this, three of that.

shuyg, you can get long round ide cables I think they can be at least 24" long. If you make an access hole in a calculated spot on the case you might make it.


#7

Thanks for all the answers. I guess it’s almost impossible to connect the 12 DVD-drives to a computer. Bandwidth is almost always a problem (firewire, pci-bus, hdd, etc.).

I used a duplicator controller, but it broke down last month. I bought it at Copystars.com, but they didn’t help my solving the problem (within the warranty period). When the controller completely stopped working, the warranty was over.

I will start searching for a new controller. For everybody else… don’t buy at Copystars.com.


#8

I’m going to use the highest data rates I found for DVD writing:
1x DVD-R = 1385KBps = ~1.36MB/s
16xDVD-R = 22160KBps = ~21.64MB/s

And on firewire…
Firewire 400 = 400mbit/s = ~40MB/s (due to overhead).
Firewire 800 = 800mbit/s = ~80MB/s (due to overhead).

It’s probably not safe to run more than one 16x DVD±R drive per firewire 400 channel. Per firewire 800 channel, you can support two, maybe three.

If you back down the burn speed (if allowable with the blank media and drives chosen), you could support two maybe three with firewire 400, and six or so with firewire 800.

So, if you want to use the bridge boards that support four drives, I’d suggest sticking with 8x burning. In addition, do not daisy chain the firewire boards but, instead, connect each to a separate firewire 800.

An alternate plan would be to look into a SATA-based solution. You can find SATA->IDE(ATAPI) bridge boards pretty cheap if you look around.

I think the biggest problem you are going to discover is the limitation of the host hard drive I/O and PCI bus, and potentially IO scheduling issues in the Windows OS (in my experience, it doesn’t schedule transactions well for parallel optical IO). A more stable solution (other than using a standalone duplicator) would be: a contemporary speedy hard drive array, much more recent motherboard and an on-board or PCI-express (PCIe) SATA controller that supports multi-lane eSATA.

And don’t even think about USB.

-brendan