Another slow file transfer question (Vista)

[Mark]

Hi
I have a number of Vista Business machines that are suffering from some
performance problems whilst transferring large files over a

network. By testing different combinations of hardware and OS I can see
that something in Vista is throttling the network bandwith. My questions are
what is throttling the network and how do I turn it off?

My setup is as follows...

I have a 100Mbit network wth several client computers, a single server and a
router connected.
The server and clients are on different VLANs and the router is used to
allow communication between the clients and server (router on a

stick configuration).
The client computers run Windows XP Professional SP2 or Windows Vista
Business RTM.
The client hardware is a mix of HP, Sony and Dell.
The server is HP & the router is Cisco.
I have a large file (>1Gb) stored on the file server that I am using to test
network performance. The file is made available via a

standard file share and accessed from the clients using a UNC path.
All copy operations are performed using "xcopy" from the Command Prompt.
I am using the Task Manager Network tab to guage the network performance.

On Windows XP, when I copy the file from the server I see a constant
throughput of around 80Mbps. As soon as I issue the xcopy command,

the throughput shoots up and stays pinned at around 80Mbps until the copy
completed.

On Windows Vista, when I copy the file from the server I initially see
throughput of around 80Mbps but after a second or so this drops

down to around 5Mbps and then remains at that level until the copy is
completed.

I've tried the copy in various different configurations...:

Domain member and non member computers (this I beleive eliminates any
possible Group Policy based QoS setting)
Fresh Vista install vs Manufacturer Vista install
Desktop vs Laptop

....all of which produce the same results.

I've tried the following fixes to no effect:
Disabling Windows Audio & Multimedia Class Scheduler services
Disabling TCP Receive Window auto-tuning
Disabling Remove Differential Compression
Application of Hotfix KB931770
Manually configured Maximum Throughput for inbound TCP under Advanced QoS
Settings in the local computer policy.
Shutting down every service that was essential to the operation of the machine

Something which may not be important but I think is worth mentioning is that
whatever causes the slow performance also seems to block the

process that is doing the copy. For example, in XP once I start the copy I
can abort it immediately at any time by pressing CTRL-C. In

Vista however I have to press CTRL-C many many times before I can kill the
copy process.

If anyone can help me troubleshoot this further or can point me in the
direction of a fix I'd me very grateful. For a business where transferring
large files around is an everyday task this issue is a major roadblock to
full Vista rollout.

Thanks for reading this long post!
Mark

 

[Mark L. Ferguson]

I believe I found your answer. "Long wire to router"
Vista is using 'IPv6" and 'tunneling'. The length of the wire used to attach
the machine to the router seems to effect the packet success. When you open
the router configuration software, you are probably going to see some
degradation in load time for that page.
When you open the Local Area Connection icon''s Properties, at the top
should be :
"IPv4 Internet"
and
"IPv6 Limited"

I am using Vista Business on a new Dell Vostro 200. The same wired
connection on another XP machine runs quite well. I'm sorry to say I haven't
found a solution. A 'short wire' to the router and the very same long wire
then connected from router to the Internet modem seems to run fine. If you
find some workaround for this "IPv6 Limited" error, please let me know.

 

[Mark L. Ferguson]

Use the Properties of the network adapter in device manager to set the speed
tab to 'half-duplex'.

 

[Mark L. Ferguson]

Thanks. All I know about it so far is that reinstalling a driver, like usb,
or ethernet, or changing speed settings on those devices, seems to
'reconnect' my system, to allow better speeds. I'm sure it's a driver
problem, and I'm checking my OEM site regularly to look for an upgrade. I'll
follow up here if I get anything better.
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Mark L. Ferguson
..