Buffer me this
The Mac Observer got some more detailed information about Retrospect 6.
My favorite quote:
With folks using faster media, typically a hard drive, for the backup target, the size of the buffer used between the source and target media became an issue. By increasing it from 64K to 1 MB, users can experience performance gains from 20% up to 100%.
Why didn't Retrospect dynamically scale the buffer size according to the amount of RAM available? A 64K buffer is sized for a computer of the late '80s. If nothing else, they should have been bumping the buffer size in each version along the way.
I'd be disgusted if I weren't so shocked and surprised at this.
Comments
If I'm reading that correctly, they could buffer everything in RAM but it wouldn't help them at all. The limiting factor isn't how much they can store in memory; instead, it's the speed at which they can write to the destination media. (Assuming that the destination media is slower than the source media, which is typically true for backups.)
Ideally they'd adjust their buffer based on the buffer size of the destination media. That might be hard for them to read reliably, though -- I'm not sure how you go about asking a hard drive for its write buffer size, or even if all hard drives report that correctly. That said, I would've expected Dantz to adjust their buffer size based on the type of media -- tapes smallest, then CDs, then hard drives. Perhaps they didn't do that before and they're doing it now.
Posted by: Eric | January 9, 2004 1:55 AM