grandpimp Posted June 18, 2002 Report Share Posted June 18, 2002 Hello I am experiencing slow backups. I'm running Retrospect Express 5.0 for Macintosh on a G4 dual 500. I'm running Mac OS 9.1. I'm burning to my internal burner, which is a Matshita CW-7586. In the Devices it's recognized as a Panasonic CD-RW with firmware version 1A17. The volumes I back up are my internal drive and one firewire drive. Normally this burner is an 8x burner, but with Retrospect it doesn't seem to be taking full advantage of the burner's speed. Retrospect starts out getting about 75 MB/s when it's copying, then quickly drops down to around 20 MB/s. It goes a little faster when it's comparing. I run Retrospect at my work and it does about 130 MB/s backing up to tape. Is this a feature of backing up to CD-R's? If not, how can I get faster backups? Thanks Morgan Quote Link to comment Share on other sites More sharing options...
AmyJ Posted June 19, 2002 Report Share Posted June 19, 2002 This drive has slow performance because it does not support continuous write commands. Retrospect has to sync the cache after each write command. From the Knowledgebase: www.dantz.com/index.php3?SCREEN=knowledgebase_article&id=868 Retrospect uses packet writing technology to write to CD and DVD drives. Packet writing speed is determined entirely by the device in use. That is, Retrospect does not determine what speed the device can support, it simply sends data to the device as fast as it can write it. Some CD/DVD drives do not support "continuous writes" in packet writing mode. In these cases, Retrospect must tell the device to write each packet, and then give it a new packet only when it has finished. Because this is inherently less efficient than buffering data and writing many packets in a row, devices that require a flush after each packet, as this functionality is called, will be much slower than their normal "disc at once" burn speed. For example, you may have a 24x drive that only writes at 4x speed with Retrospect because the drive does not support continuous writes. This doesn't mean the drive doesn't work, it just means the drive works slowly with Retrospect. Obviously the best CD/DVD drives to use with Retrospect are ones that support continuous writes. Quote Link to comment Share on other sites More sharing options...
grandpimp Posted June 20, 2002 Author Report Share Posted June 20, 2002 thanks, amy. can anyone recommend a burner that supports continuous writes? Quote Link to comment Share on other sites More sharing options...
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