On Fri, Nov 13, 2015 at 6:06 PM, Rick Stevens <ricks@xxxxxxxxxxxxxx> wrote: >>> >>> Is there something in Fedora that I might use to determine the >>> maximum >>> speed the network card of my computer can attain on Internet? I am >>> thinking about wired Internet and not about wireless Internet. >>> >>> Thanks in advance, >> >> >> You might need to explain the reason for your request since, it may >> change the answer. >> >> As an example, my computer has a GigE port that runs to a 100Mbit >> simple switch before getting to anything else. So I would be limited >> to a theoretical maximum of 100Mbit but I might want to know how fast I >> can transfer files to/from another computer in my LAN. The bottleneck >> here could be the switch, my NIC, the other computers NIC, OS limits, >> firewall slowdowns etc. >> >> So, for me I would really want to test an actual file transfer using a >> number of setups. Depending on each computer I could try Samba, FTP, >> SCP. I might run a wire to bypass the switch. I might try with >> firewalls and antivirus disabled. >> >> All this will also give me some clue on how fast I could run if I was >> able to get a fiber connection, to let me know if my system would be a >> serious limit to getting the full 1G of true fiber. Obviously the >> switch would have to be upgraded in my case. > > > Generally speaking, any given NIC that has proper firmware and is in > a relatively modern computer will run very close to the rated wire > speed--provided the other end of the cable can handle it as well. Note > that the effective transfer rate will usually be about 80-95% of that > (for a 1Gbps NIC, 800-950Mbps). > > This does not include any overhead involved in the protocol used. You > will find that things like FTP, rsync and the like will show lower > data transmission rates (e.g. multiplying the number of bytes > transferred by 8 to get number of bits transferred) due to their > overhead and that they're dealing with TCP's inherent nagle algorithm > and handshaking. TCP is designed to make sure things get to where > they're supposed to go, and with that comes a lot of overhead. Things > like UDR (rsync-over-UDP) will show much closer to the theoretical data > transmission rate due to its use of UDP. > > The most common bottleneck to raw speed is the wire, switch, router, > gateway or ISP that the NIC is connected to. You'll rarely find the NIC > itself the limiting factor. Thanks to all respondents! I could now determine that my network card is a 100Mbps Fast Ethernet, and now it is clear why the speed test (http://www.speedtest.net/) shows a download speed of just 85 Mbps when my contracted speed is 120 Mbps. Paul -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
