Help Please - Vista Network Bandwidth degradation

94porkr · Dec 24, 2008

I am having issues with my Vista machine's network bandwidth ---

It is a WIRED connection to a Linksys WRT54GS using a Marvell Yukon 88E8071 PCI-E 1GB network adapter.

Over the course of time the Vista machine is up, the network bandwidth download speed decrease significantly ( 60% of what it should be ). Rebooting restores the bandwidth to what I think it should be ( My wirless XP machines (2) work perfectly ).

I have updated the network adapter driver, removed the MMCSS dependency, and disabled TCP autotuning parm ( using netsh ). Nothing has worked -- Can you help ?

Here is the test run after the machine has been up and running for few hours :

8854d1230134185-whats-your-internet-speed-pic-vista-speed-test-problem.jpg

( bottom number is upload speed which is greater than download speed !!!!!!! :confused:

)

Here is the test run directly after rebooting :

8853d1230134185-whats-your-internet-speed-pic-vista-speed-test-after-reboot.jpg

I am also attaching a summary so you can see the fluctuations ( left hand column is download / right is upload speed ) :

Invictus88 · Dec 24, 2008

These are testing your WAN bandwith, if other computers on the network are downloading/uploading then it will lower your WAN bandwith. Basically, this isn't an accurate measure of your network card since there are so many other things coming into play (your ISP, peek usage times for your ISP, latency between hops, etc). Try transferring a file over your network and see if it's slow. If your network card is actually being slowed down then your files would transfer extremely slow. Also, if it is a 1gbps adapter then your actually being lowered to a lot less then 60%, 1gbps = 1,000,000kbps so if your actually being lowered to 5000kbps then your actually at 0.005% of your network adapter's speed, which I doubt. And yes I know that 1gbps isn't actually 1,000,000kbps after overhead, etc, either way it doesn't add up...).

So, try transferring a large file after restarting your computer and see how fast it goes then try transferring one when you think its slow and see how fast it goes. Post the results here.

94porkr · Dec 24, 2008

Invictus88 said:
These are testing your WAN bandwith, if other computers on the network are downloading/uploading then it will lower your WAN bandwith. Basically, this isn't an accurate measure of your network card since there are so many other things coming into play (your ISP, peek usage times for your ISP, latency between hops, etc). Try transferring a file over your network and see if it's slow. If your network card is actually being slowed down then your files would transfer extremely slow. Also, if it is a 1gbps adapter then your actually being lowered to a lot less then 60%, 1gbps = 1,000,000kbps so if your actually being lowered to 5000kbps then your actually at 0.005% of your network adapter's speed, which I doubt. And yes I know that 1gbps isn't actually 1,000,000kbps after overhead, etc, either way it doesn't add up...).

So, try transferring a large file after restarting your computer and see how fast it goes then try transferring one when you think its slow and see how fast it goes. Post the results here.

Will do -- BTW, the other PC's are idle when these speed tests are being done ( non-peak ISP times ) -- I truly believe it is Vista -- the other XP machines do not exhibit any issues like this.

94porkr · Dec 28, 2008

Ok so the network is starting to degrade -- here is the start points

Downloaded a Photo Album of 200MB in 4 mins 30 secs

Degraded speed test result :

Downloaded the same Photo Album of 200MB in 8 mins 40 secs

So it is NOT the network adapter but rather Vista slowing down the bandwidth --

does anyone have any suggestions as to what to try ?
...or did the Vista rewrite of the network "stuff" really hose things up forcing a reboot to return to normal levels of performance ?

94porkr · Jan 7, 2009

Bump for response

94porkr · Jan 16, 2009

I am still racking my brain over this bandwidth degradation problem --- every day I have to reboot the Vista computer to restore the bandwidth performance --

Isn't there anyone with any ideas for me on what to try ? :mad:

dk70 · Jan 16, 2009

Try default all over again

You changed some buffer/caching setting in adapter? Other Vista net-tweaks?

Latest drivers for that thing should be 10.66.4.3 - you state 10.64.10.3 in sys-spec.

Tried their diagnostic tool? Will probably just reset settings to default but still.

Tried resetting router? Firmware?

Since you mention netsh you probably have not messed up - but may be post result of "netsh interface tcp show global".

So you timed downloads and numbers are correct but if you use certain webfilters/proxies from AV programs they can screw up result from sites like speedtest. Like cutting in half or double! Probably not relevant but no more ideas.

Help Please - Vista Network Bandwidth degradation

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