Hi there, On Tue, 30 Dec 2003, Steve wrote:
> This is interesting as the stable datum has always been that SCSI, with better > processing abilities and less need of help from the CPU, should run with a > lower CPU load. > > In fact SCSI traffic has a much higher volume of instructions in it than IDE, > which is processed by the controller and drive. You have f.ex the ability to > process mutiple requests at the same time, something IDE cannot do. > > What kind of number do you have, i.e. what actions results in what CPU load on > the two? Here are some timings for copying last night's backup :) which is a 1.64GB file, from partition to partition on our public webserver. The load figures are *very* rough, just form looking at 'top' during the copying. The times are accurate (from system timestamps). SCSI-SCSI 2m 13s 20-30% CPU (partition to partition, same drive) SCSI-IDE 1m 11s 10-20% CPU IDE-IDE 4m 34s 10-20% CPU (partition to partition, same drive) The SCSI drive I used is 72.8GB 10,000 rpm U320. The IDE drive is 250GB 7,200 EIDE (WD25000JB). There are other drives on the machine, if you want to see more comparisons it's possible but I'd need some time to work on it, very busy just now (new year's prices on about 36,000 products :). The machine is a Compaq Proliant DL380, 733MHz PIII with 1GB RAM running a light-ish load. Usually about 100 processes including several webservers, a mysql database, a Java VM, mail, two or three users, crontabs etc., most of the time less than 10% CPU load and a load average of 0.1-0.3 with negligible swapping. This performance isn't what I'd call spectacular and the drives are capable of much better in a system with a faster bus. As I said I haven't spent a lot of time worrying about it because it's well on top of the load. If you want to discuss this more we should take it off-list. 73, Ged. ------------------------------------------------------- This SF.net email is sponsored by: IBM Linux Tutorials. Become an expert in LINUX or just sharpen your skills. Sign up for IBM's Free Linux Tutorials. Learn everything from the bash shell to sys admin. Click now! http://ads.osdn.com/?ad_id=1278&alloc_id=3371&op=click _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-users
