Struggling With Low Speeds < 15MBps Over Gigabit

Hey Guys

I have been having a major PITA regarding transfer speeds ever since I purchased my 'ReadyNas Ultra 4 Plus' in May 2011.

Originally, I was only getting approx 5-6 MB/second and came to the conclusion that it was probably due to using 'Netgear Homeplugs', which apparently didn't support jumbo frames even though they were the 500MBps version .

I also discovered that the integrated Broadcom network adapter within my 'Dell XPS8300' didn't support jumbo frames either, despite that being Gigabit. :shock:

Requiring faster transfer speeds, I ditched the 'Netgear Homeplugs' and invested in an 'Intel Gigabit CT' network adapter as well as a TP-Link TL-SG1005D5 5-port unmanaged Gigabit switch.

This increased the speed to approx 10-12 MB/second and I've put up with that for a while now.

However after recently reading a webpage, 'Bott's Thoughts' dated 2010, I was disappointed to read that I should be expecting around 80 MB/second :shock: .

So I want to try and get to the bottom of this poor network performance once and for all.

Current set up consists of:

'ReadyNas Ultra 4 Plus'
RAIDiator 4.2.23 (v4.2.24 Available)
4 x 2TB SAMSUNG HD204UI - 5400RPM - RAID-5
4GB DDR2 Memory Upgrade
Auto Negotiation @ 1Gbit/Full Duplex
Jumbo Frames/Packets Enabled
IPv6 Disabled

Main PC
'DELL XPS8300'
Intel i7-2600 CPU @ 3.4GHz
Window 7 64-bit
2 x 1TB Western Digital WD10EALX - 7200RPM RAID-0
16GB DDR3
Disabled Onboard Broadcom Gigabit Network Adapter (No Jumbo Frame/Packet Support)
Intel Gigabit CT Network Adapter
Auto Negotiation @ 1Gbit/Full Duplex
Jumbo Frames/Packets Enabled = 9014
IPv6 Disabled

Router/Switch
Billion BiPAC 7800N
Firmware 1.06h
4 x Gigabit Ports
Jumbo Frames Enable by Default (Apparently)
DHCP Server
IPv6 Disabled

Unmanaged Switch
TP-Link - TL-SG1005D
5 x Auto-Negotiation Gigabit Ports

Belkin CAT5e Cables / All Tested

Currently, the ''Dell XPS8300' PC is connected directly to the 'Billion 7800N' router/switch (both upstairs), which is then connected to the unmanaged switch downstairs via CAT5e cable.

The switch is then connected to:
'ReadyNas Ultra 4 Plus'
MEDE8ER Multimedia Streamer
'SKY HD' Receiver
XBOX360 Slim
Samsung BD-C5900 3D Bluray Player

For test purposes:
I copied a 3.2GB file from the 'ReadyNAS' to the 'Dell XPS8300' and the average Windows reported read speed was approx 100MBps
I copied the same file back and the average Windows reported write speed was 11MB/second. :?

Moved the same file from the 'ReadyNAS' to the 'Dell XPS8300' and the average Windows reported read speed was approx 120MBps
Moved the same file back and the average Windows reported write speed was 10MB/second. :shock:

Done the same with a 'HP 8000 Elite USDT', which is also Gigabit and the results were similar.

The results from a utility called 'LAN Speed Test' (3GB test file to the same folder) show the following:
Average Read Speed: 29MB/second
Average Write Speed: 18MB/second

Surely the write speed to the 'ReadyNAS' should be better than 10-12MB/second?

The only thing I haven't tried is a direct cable connection between the 'Dell XPS8300' and the 'ReadyNAS' as I don't have a cable long enough as present.

Going to order a Belkin 20m CAT5e or CAT6 cable now and see if that improves speeds any.

Is there anything obvious I've missed?

Looking at the above, I'm now wondering whether the difference in drive speeds between the 'Dell XPS8300' and the 'ReadyNAS' is causing this.

If so, would the expected transfer rate be affected that much or is it more likely to be an external hardware or even a software/driver problem?

Any ideas welcome.

Oh, and if you got this far without losing the will to live, then well done! You deserve a medal! :D