maybe an easy question to answer

I have several PCs on my home/office network. Each has the latest in motherboards (i.e. eVGA 680i and intel core 2 processors, 2Gb RAM) and each have 2 x 1 gb LAN ports . I have a 24 port - 1gb switch and have Cat 6A patch cords running where-ever there's cable.

So the question is; why does it still take 10 minutes to move a 3.5Gbyte file from one PC to another.

I calculate that at 1gbps that = 0.125 Gbytes p/s and for a 3 Gbyte file should take < 1 minute? Maybe with overhead it takes longer, but why 10+ minutes?

What can I do to move the files faster (over the network)?

I can put fiber in, but I am sure it's not the network switch/cable/nic hardware that's bottlenecked at this point?

thank you

thank you. That was the type of information I am looking for.

So basically I would have to go with RAID stripes to increase speed. I guess I couldn't expect better than 60-150 mbps from an SATA RAID stripe at best? Is this what I am understanding?

well, as Arimoto pointed out (as did I in my original post), it is not a network issue. A 1 gigaBIT network can handle gigaBYTE files quite easily. This is still ~0.125 gigaBYTES per second. That's pretty fast in terms of moving a 10 gigaBYTE file in 80 seconds! I would be quite happy with that, but that is the theoretical network speed once the data is available to the network. I was sure there was something else bottlenecking the transfers and Arimoto points out what I was unaware of; the hard drive transfer speed.

3.25 GB / 10 minutes ~ 5.4 MB/s. This is well under the performance of all modern HD's and gigabit networking, and indicates that there is a performance problem somewhere.

There are numerous potential causes of such poor performance. E.g.:

- you have IDE HDs running in PIO mode instead of DMA. You should be able to see this in the drive connection properties, or as very high CPU utilization during file access.

- you're using poor RAID 5 implementations on the writing side, esp. with write caching disabled.

- you're using very crowded drives with badly fragmented files.

- some other process is rapidly accessing the HDs during file transfer

- some other process is flooding the network/switch with traffic

- you're using a 100 Mb/s switch or any of the NICs aren't negotiating gigabit connection speeds.

- perhaps a problem due to multiple network connections from a single computer -- multiple network connections typically don't work as you expect; I'd recommend reducing them to single connections for further diagnostics

If none of the above sort of potential causes are to blame, the way to proceed would be to look at individual component performance -- network, drives on both sides, and then back to composite as controlled file transfers across the network.

E.g. for network-only performance -- using iperf 1.7:

server: iperf -s
client: iperf -c server -l 64k -t 12 -i 3 -r

This will tell you if you have a network-level problem or a problem elsewhere.

Drive performance can be tested with tools like iometer or even HDTach or ATTO.

[quote="cc3d"]MadWand, thanks. This is good info.





- you have IDE HDs running in PIO mode instead of DMA. You should be able to see this in the drive connection properties, or as very high CPU utilization during file access.

All drives are SATA



This is a good dicussion with a lot of great info. I will say though that since your are running XP your drives would automatically be set to DMA unless a upgrade changed somehow. Besides the fact that you are also running SATA drives.

8O