I've got hold of a separate disk on which to have my swap partition. I believe this will give a performance boost.

I currently have my first hard disk on ide channel 1 with cdrom as slave, and second disk on ide channel two.

Would it make any difference (for better or for worse) if I put the two disks on one channel and left the cdrom one its own as master?

What is the most efficient set up with a view to maximising disk performance, and ignoring the cdrom?

Many thanks, reetep.

I've heard (although never tested myself) that putting two hard-disk drives on separate IDE channels will improve their performance. This is because a hard-drive that is mounted and in use will be frequently sending information across the IDE data channels, so it is faster to separate the two drives and therefore the two streams of information. Therefore, I'd say that putting your main hard-disk as primary master and your CD drive as primary slave, and your other hard-disk as secondary master, would be a good plan to increase performance. However, you should check into it more carefully from the boot perspective, because you might not be able to boot from CD if you configure your system like this. (As far as I know, my system will only boot to a master device, but I'm not entirely sure that all systems do that.)

The bandwidth of an IDE or ATAPI channel is shared between both devices, so it's best to keep the hard disks on seperate channels if you can, or the devices will slow down.

The CD won't take up any bandwidth unless it's being used. If you really want maximum performance even with the CD being used, buy a second IDE controller (on a PCI card) and put the CD on that.

Also, note that swapping only kicks in when you run out of free RAM pages; you might want to play with /proc/cpu/swappiness in recent kernels to control the balance between RAM cache pages and application RAM pages, which directly affects how many pages are free in RAM.

To make the hard disks go faster, you could look also at using software RAID, or even buying a RAID controller.

Thanks guys that's great. I'll give it a go on separate channels and then experiment further just for fun

Thanks also for telling me about /proc/cpu/swappiness - I didn't know about that. Do you have any particular recommendations for someone who

a) has 256MB
b) has 512MB

?

Thanks again, reetep.

The value to put in swappiness doesn't really have anything to do with the amount of RAM you have.

Basically, the lower the value the more likely you are to use cache memory rather than swap space, making applications more responsive but possibly slowing down hardware access.

Ok thanks, I'll definitely do some googling on that to check it out