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Slow backup to CD-R on 2 PCs


plb

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I have tried back-ups on two different PCs and get similar results. I did full and various partial back-ups as tests. In all cases, through-put ranges between 20 and 32 MB/minute. These same PCs got about 60 - 70 MB / minute with Seagate Backup Exec.

 

I have done backups with and without software compression. And with and without the "backup security" option set. Never used encryption. No significant differences among the permutations.

 

Both PCs run Windows 98 Second Edition. One is a Pentium III 750 MHz; other is a Pentium II 450 MHz. In both cases, I was doing a local backup of the C: drive to a built-in CD-RW drive with CD-R discs. Here is the device configuration information for the two involved drives:

 

SONY

CD-RW CRX140E

version 1.0n

SONY CD-RW (1.53)

 

HP

CD-Writer+ 9100

ver 1.0c

HP CD-RW (1.53)

 

The feature/function in Retrospect is great, except for this ultra slow speed. Would anyone have suggestions about how I can speed up the backups? Thanks in advance for your help!!

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Hello,

 

Here is some further troubleshooting information that may help identify the root cause:

 

On the PIII machine I did a small test backup to an internal Zip250 ATAPI drive. The backup was 2,386 files, 234MB. This ran at 45 MB / minute, significantly faster than the Sony CDRW drive. To me, this seems to point to something about how Retrospect 6.0 works with the Sony CDRW drive.

 

I also went to device manager and turned off DMA access. This had no effect on backup speed with the CDRW drive - still in the range of 22 to 30 MB per minute.

 

Again, I am seeking ideas about how I might be able to dramatically increase the backup speed with the CDRW drive, in both computers as mentioned in my original post.

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Another consideration is how the IDE devices are arranged. IDE is a "single transaction" bus (can only do one read or write a time) so that putting two (master/slave) devices on the same IDE bus will result in slow performance if both devices are in use (e.g. copying from HD to CDRW, or CD to CDRW). For best backup performance, put the CDRW and your HD on different IDE buses.

 

You can probably put the CDRW and your Zip in the same IDE bus, assuming that you seldom copy files between the two. If you run out of IDE positions (can't put enough stuff on different IDEs, cabling issues, etc.) you can pick up a PCI-IDE card (provides two more IDE connectors => 4 more IDE devices) for about $50.

 

And you also really want DMA *on* if you want decent speed. I was recently using a 24x CD writer that was really slow (tested at about 1x speed) until I noticed that it was in PIO (polled IO) mode and couldn't keep up with the copy. Fortunately the "burn-proof" underrun capability prevented coasters and instead just slowed it down. Switching to DMA allowed me to burn at the max 24x speed.

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This program is pretty much a hit or miss kind of thing when it comes to the usage of packet writing. For the longest time I couldn't get my 24X drive to burn faster than 30mb/min... My 8X drive would also do the same. The only thing that solved the problem was getting a new, reliable cd burner. I went with the Plextor 48X24X48A and haven't looked back. My backups run between 280mb/min and 340mb/min.

It's basically the only thing you can do at this point. Tech support here won't help you find a solution because the solution lies in redesigning the software, and I don't see that happening any time soon.

For what it's worth, just spend the $175 for this burner and all of your problems will be solved.

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I don't back up to CDR/RW (too small, too slow, too much trouble and, based on forum reports, not always reliable with Retrospect)--instead I just back up to other HDs.

 

But my my CDRWs are Lite-Ons (with buffer underrun; excellent repulation with copy-protected CDs), and I get great performance when using Nero and other CDR/RW software. At under $60 (for 40x, 48x, etc.), they're a heck of a lot cheaper than the Plextors and the $175 that was mentioned.

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Hi Folks,

 

Thank you GoAWest and sonic_debris. Based on your suggestions and on a couple of long conversations with Dantz tech support, I've ordered Lite-On 52x24x52 CDRW drives. Got them from Dell for $56. They should arrive by Monday 2/3. Once I see how they work, I'll put up a note here about the outcome.

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Dell delivered early; here's the outcome: I also purchased Belkin Ultra IDE cables for $18 at Best Buy - they say it improves performance even for Ultra DMA Mode 2. In these backups, I used Memorex 52X CD-R media.

 

 

 

Pentium III 700 MHz, Win98SE:

 

Copy phase: 228.5 MB/min (instead of 20 - 30; 10-fold improvement)

 

Compare phase: 87.9 MB/m

 

Overall: 126.9 MB/m

 

 

 

Pentium II 450 MHz, Win98SE (accidentally done with McAfee antivirus and firewall ON):

 

Copy phase: 127.0 MB/m (instead of 20 - 30; 6-fold improvement)

 

Compare phase: 90.1 MB/m

 

Overall: 105.2 MB/m

 

(Probably will be better when I remember to turn McAfee off...)

 

 

 

Tech support had said not to expect to be able to get close to 100 MB/m.

 

 

 

I'm very pleased - with the Lite-On drives and with the Retrospect performance. Thank you again for your suggestions and guidance - very helpful in getting to this great outcome.

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