Poor network performance (x-over cable/FTP)

[Stuza]

HI Guys

im trying to get HD stuff to stream and its jerky as hell so, in order to rule out the network I dropped back to a x-over ethernet cable with the server direct to a device (I tried a laptop and a HD media player). However, this was still jerky. So, next step, I put a free FTP server on the server and then tried to connect via FTP and copy over the file. The best I could get was 11meg a second.

For the life of me, in my simple view of things, all seems good so, I thought i'd ask the experts for tips. Please take a quick look at the specs below and see if you can see why I'm only getting 11meg and im open to suggestions!


Desktop(Ftp server)->x-over->Laptop(Ftp client) = 11meg a second
Desktop(Ftp server)->homeplug(bedroom)->Laptop(Ftp client) = 4meg a second

Ouch. So none of these are particuly good considering the direct connection with nothing in the middle.

The PC's specs:

Intel Core 2 Duo E6850 @3.00
Ram 4gb
Vista Home Premium 64
Boot disks SATA1: 2xWD Raptors (stripe)
Storage SATA2: 2x Hitachi 1TB disks (stripe)

Important bit?:

Generic Marvell Yukon 88E8056 Ethernet Controller

Settings below, any ideas?

• Flow control - TX/RX Enabled
• Interrupt Moderation - Enabled
• IPv4 Checksum Rx Enabled
• Jumbo Packet - 1514 (smallest option, cant disable)
• Large Send Offload (IPv4) - Disabled
• Max IRQ per sec - 10,000
• Priority & VLAN - Priority and VLAN Disabled
• Receive Buffers - 512
• Speed & Duplex - Auto-Negotiation (tried forcing 100/full)
• TCP Checksum Offload (IPv4) - Tx & Rx Enabled
• Transmit Buffers - 256
• UDP Checksum Offload (IPv4) - Tx & Rx Enabled

The devices connect at 100meg but I can't see where to see if this is Full duplex or not.

So, any ideas? I'm really struggling.... and very confused

Thanks in advance!

[Stuza]

anyone? please?

[johnwill]

First off, homeplug is much slower than a CAT5 wire. Second, you're confusing bits and bytes. You have a 100mbit/sec connection, which translates to 12.5mbytes/sec. Getting 11 mbytes/sec on that connection is full speed, as there is some protocol overhead for the SMB protocol, as well as TCP/IP framing. If you really need faster transfers, you need to be looking at gigabit Ethernet connections.

You're struggling with a non-issue.

[Stuza]

im pretty sure your wrong on this, you missunderstand me or you haven't explained it properly.

For a starters, Ethernet will only operate at 40% capacity and rapidly descends into chaos at that point!

Soo ..... 100meg/8 = 12.5, this you are correct on BUT
I have NEVER seen an ethernet network achieve above 50% in my life so, that means
50 meg (useable)/8 = 6.25.

However, i don't think I am confusing Mbit and Mbytes and my maths above seem to suggest that as well as I physicaly could not run ethernet at 100%! Will confirm when I get home.

Also, I'm using FTP not SMB for these speed tests (test with the simple, then introduce the complex) and the homeplugs are not being tested on the simple speed test - that was just so you can see where I want to go to.

This is the current test setup, nothing complicated:

Server <--- xover ethernet --->client

[johnwill]

Actually, I don't know where you get 40% for maximum capacity, but I can routinely get 9mbyte/sec transfers (SMB protocol) over a 100mbit link to some NAS boxes here, so you're mistaken. You're also living in the past with the Ethernet capacity numbers, because that was in the days of hubs and coax, where there were many collisions with high traffic. Even then, the figure we normally used was 70%. With full duplex switches in the mix, there are far fewer collisions, because all of the addressed traffic is routed to the specific destination and not to all stations. Broadcast packets are the only ones that are routed to all the stations.

If you've never seen over 50% utilization, I suggest you come to my office and look at my network.

Finally, I'm not sure what your issue is, because if you believe your 40% number, you're getting more than you should, so the performance isn't really poor, right?