I am trying to maximising the bandwidth of my gigabit network.
I have a desktops connected using Cat5e cables over a gigabit network. My maximum transfer rate is about 23MB/s. I am using an onboard gigabit (realtek) on my motherboard (MSI) and the other computer on a PCI network card. The transfer rate on a 10/100 network is about 6MB/s. I used to achieve about 30+~40MB/s on the network interface on my old motherboard with the same computer connected.
My questions are:
1. Is the speed an average of what a gigabit network?
2. Will installing a new network card on the computer using the onboard gigabit interface improve the speed?
3. It seems that the onboard network interface is limited to USB speed? How do I know that it is limited to a certain speed?
A lot of system factors can influence LAN performance, this can turn into a tricky issue.
1. Gigabit networks can really achieve gibabit speeds. About 920 Megabits per sec is the theoretical max. (note that's "bits" not bytes). But you'll never see these speeds if you're using FTP. Hard drives are slow by comparison.
2. Maybe. Some network controllers use lots of CPU cycles xmit & rcv data (rather then HW offloads). Performance could suffer when your system is busy if you have that kind of Ethernet controller. I don't currently have any Realtek stuff... I can't say how their work.
3. Onboard Ethernet is not limited by USB. Different HW, different driver models, different needs.
- Both ends of the wire are important. System A may have a great adapter but if System B is crap, that's what you'll see in any performance run.
- Hard Disk to Hard Disk data transfers via FTP will be limited by the drive and controller at each end of the wire. (FTP is no speed demon either).
- Does your network support Jumbo Frames? Eabling this feature can really help with file transfer traffic (but hurt if you have a lot small packets).
LAN vendors tend to test their configurations with Chariot which is more of a memory to memory benchmarking tool that uses several remote computers to simulate different traffic patterns (if want to measure consistent performance you need to work around HW limiters that you have no control over).