Double checked your details and calculated the following:
PC A: P4@2.4Ghz
PC B: PHIIx4@3.5Ghz
xfer 1 x 10GB file from A to B
Using A = 15min
Mb/s= 10GB/15min x min/60sec x 8Gb/GB x 1000Mb/Gb = 88.8Mb/s
------------ = 88.88Mb/s
Using B = 60min
------------- = 22.2Mb/s
I'll leave the original text below unchanged, as it still applies in general.
Your results show the opposite of what one should expect. While file xfers don't use alot of CPU time, using the Phenom II X4 should have been much faster than using PC A (P4M@2.4Ghz).
So what you're doing is using PC B(X4@3.5Ghz) to go through the network, read data from PC A hard drive, then bring it back through the network, and WRITE it on it's own HD.
The problem seems to be originating on PC - B.
I'm wondering if the NIC on PC-B is set for half-duplex, or if the offload options on the NIC are disabled. Some NIC's allow some of the work to be offloaded FROM the CPU to the NIC to enhance network performance. This way, the NIC does more work on it's own WITHOUT "interrupting" the CPU. It may be that the offload settings on PC B NIC are disabled instead of being enabled. I'd also ensure full-duplex and flow control is enabled on PC B (as well as A for that matter).
If all these things are already set, then i'd swap network cables and try the exact same test again. If the results are opposite, you have a cabling problem, again assuming both NIC's are set to full-duplex, auto-negotion and flow-control enabled.
The information below I'll leave as-is, even though it doesn't specifically resolve THIS particular issue, just gigabit network performance in general. Apologies!
It seems the write speed of the drive on machine A is much slower than B. (EDIT: <--- does not apply since this was a one-way only test, not two-way)
Write and Read speeds of your drives are probably going to be the limiting factor in network file xfer performance.
I'm betting machine A (P4@2.4Ghz) has a much slower drive with much slower write speeds than the drive you used on machine B (AMD @ 3.5Ghz).
Reads are generally much faster than writes, so that if you're writing to a slow drive, it will take longer to xfer a file to it, than it would to copy a file FROM the drive since you'll be reading from it.
Both PC's would probably benefit from being on a gigabit network which has:
1 - Gigabit NIC's (enable JUMBO frames, which should NOT affect internet throughput, but just increase your LAN throughput)
2 - Gigabit Switch, preferably a 'nice' one from HP (have this one myself), or even Netgear (http://www.newegg.com/Product/ProductLi ... ch&x=0&y=0
3 - Cat5e or Cat6 network cabling throughout
Be aware though, that if you're xferring lots of small files, even on a gigabit lan, the throughput will be noticeably less than if you're transferring large files.
I usually get between 250Mb/s to over 800Mb/s file xfers both ways between laptop and PC which have native Gigabit NIC's.
Of course, there is a 4th option for even better performance...
Put the data you need to xfer on SSD's on BOTH PC's. The performance I noted above, is with data NOT on SSD's though I have them as boot devices on both devices mentioned.