Stephen Torri writes: > On Sun, 6 Jan 2002, Ian Truelsen wrote: > >> Recently I have been transferring some large files between my computers. I >> have a 100Mbps connection between the two, but the actual transfer speed is >> being reported at less than 3Mbps. Now, admittedly, one of the computers has >> a UDMA 33 drive, but still, 3Mbps seems awfully low. Is this normal? If not, >> what can I look to to troubleshoot the problem? > > This is something that I have found confusing myself. If the card's speed > is 100 Mbit / sec. Don't I have to first translate that from bits to byte > and account for any overhead? If I did that then with a standard 8 bits / > 1 byte then I take the 100 x 10^6 Bit / sec = 12,500,000 byte /sec. How > much is taken up with a standard Ethernet communication overhead (30%)? If > we assume an unreal world number of 0% then the above transmission speed > is rather slow in comparison to the ideal. Yet we our HDs IDE/SCSI > controller should typically be faster than 12.5MB/sec so where is the > bottleneck? You might test each HD via hdparm and see what the average > through put is for the drives. > It looks like, in my case anyway, that the old UDMA33 drive in my server is the bottleneck. hdparm -t reports it as doing buffered reads at a little under 4 MB/s, which is about the speed I am getting, minus a bit for network overhead. I do intend to replace it, but I might just move the timescale up some now :)
Thanks for the response. I didn't really know all that much about hdparm. I'm going to have to look into it a little more. Ian. Ian Truelsen Masters program in Philosophy University of Manitoba, Winnipeg, Canada BA (Wilfrid Laurier University) Email: [EMAIL PROTECTED] Current favourite quote: "No great civilisation likes forests." K.F. O'Connor Lincoln College, Christchurch, New Zealand _______________________________________________ Redhat-list mailing list [EMAIL PROTECTED] https://listman.redhat.com/mailman/listinfo/redhat-list
