Submit Hint Search The Forums LinksStatsPollsHeadlinesRSS
14,000 hints and counting!


Click here to return to the 'Why does it work?' hint
The following comments are owned by whoever posted them. This site is not responsible for what they say.
Why does it work?
Authored by: xeroply on Apr 04, '02 11:17:12PM

Well, Barry Sharp's reasoning is that if the system forces the swapfile to occupy a contiguous space on the disk (as he speculates that it does), then moving it to another disk won't make any difference, since it's equally unfragmented in either place.

However, I think he forgot to take into account I/O competition -- that is, the idea that having the swapfile on a different disk than your system and applications should reduce the time that VM paging operations spend waiting for other disk operations to complete, and vice versa. I don't know how big this difference is, but it could account for people seeing improvements after moving the swapfile.



[ Reply to This | # ]
I/O competition from different disks
Authored by: makip on Oct 12, '04 06:26:45AM

A further clarification: moving a swap file to another disk improves performance if that disk can be accessed independently of the system volume.

SCSI and SATA drives can be read and written to simultaneously on the same bus, but ATA drives cannot, they would need to be placed on seperate busses for a performance increase.

Maki



[ Reply to This | # ]