Hi,

I am presently using OS 10.4.11 and use Retrospect 6.1 to back-up my mac every day to a firewire hard-disk. If it's a "normal" back up, the whole process takes 40 min to an hour. If it's a "recycle" back up, that process takes several hours.

The question I have is, while Retrospect is backing up my Mac, does SAH stop processing, so Retrospect can have the most access to the hard disk and the processor? Or do these two applications have to "share" resources, which will cause both a delay in the back-up and mess with the verification step of Retrospect?

Thanks!

The question I have is, while Retrospect is backing up my Mac, does SAH stop processing, so Retrospect can have the most access to the hard disk and the processor? Or do these two applications have to "share" resources, which will cause both a delay in the back-up and mess with the verification step of Retrospect?

I don’t know about that particular program, but you can check for yourself with Activity Monitor. BOINC’s use of the disk is usually very light (albeit fairly frequent), so it’s mainly CPU usage that will be relevant. BOINC applications are supposed to run with a very low priority, so that even “background” functions take precedence. It’s been reported that this sometimes doesn’t work as it should under Leopard (OS 10.5.x), but since you’re running Tiger I doubt there will be any contention here.

See what percentage of the CPU’s time Retrospect typically occupies with nothing else running during a backup (I would expect it to be fairly low), then compare that to what it does while BOINC and the S@h app are running. Unless it’s significantly lower in the latter case, you can be pretty confident that the proportion of CPU cycles taken by S@h would have been idle or unused anyway.

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