Bandwidth limit on desktop PC

[pgudge]

When running www.speedtest.net on my desktop I always used to get about 65Mb/s ~ 69Mb/s download speed. In the last couple of weeks it dropped to 40Mb/s. I contacted my ISP (I am on a 80/20 trial) and they confirmed I was still on the trial.

I checked on my Server and Laptop and both report upto about 69Mb/s.

The desktop is more than capable, i7, gigabit onboard (Asus P6T Deluxe), gigabit switch, all devices show up as connected at 1.0 Gbps, and like I said it did used to connect at those speeds. The laptop is up to date on Windows Updates just like the desktop. I have Microsoft Security Essentials installed on both, and disable live protection also.

I have swapped/changed cables, makes no difference.

What can I try next?

Thanks,

PaulG.

[shaithis]

You cannot do anything about it.

It is either contention at the ISP level (your provider hasn't got the capacity) or speedtest was running out of capacity.

Try at a quieter time of day.

[jonathan_phang]

As above, could just be speed test. What I tend to do is go to gamershell.com and then go to download one of the newer demo games, picking one of the emptiest UK servers. Should be able to see if your download speed then. I've used that numerous times to check if I am getting my full 30mb from Virgin.

[pgudge]

Sorry, I should have been more precise, if I run the test on my desktop it gives 40ish, once its finished I run on Laptop, and its between 65/69, I run on Server and its 65/69, run again on desktop its limited at 40. Its nothing to do with ISP.

Thanks, PaulG.

[shaithis]

The only way I can conceive of that is if you are connected on the desktop via Wifi....but you say it's using a 1Gbps ethernet.

I doubt it's the cable either as it would probably drop sync to 100Mb in the first instance if the cable was that bad.

DD-WRT allows MAC/IP based throttling but you would have to have enabled it and would know you had done it.

[pgudge]

Yeah, all wired. the laptop on wireless gets about 30Mb/s but when connecting wired to switch jumps to 69Mb/s. The gigabit switch is connected to the Gigabit port on a Draytek router and nothing setup on there to restrict by IP or anything, everything has been fairly standard and still is.

I installed LogMeIn and the Hamachi clients a while back, but I have uninstalled and rebooted since then. Recent updates have been for, which match what is on the laptop. I also updated the Desktop NIC drivers which didn't improve.

GoToMeeting (5.1.0.880)
MSE (4.0.1526.0)
Windows Live Essentials 2011 (15.4.3555.0308)
Adobe Flash Player 11 ActiveX (11.2.202.233)
Adobe Flash Player 11 Plugin 64-bit (11.2.202.233)

Thanks,

[scaryjim]

If the rest of your PC is working at normal speeds then tbh I wouldn't worry about it too much. It might be worth trying some file transfer tests or some such to see if the network speeds within your network are causing the problem - or try a different browser in case something in your browser is limiting the transfer.

Oh, and one last thing - I assume you've checked that you're using the same server for all the speedtests? I've seen massively different speedtest results between different servers...

[Dareos]

Speedtest has been ridiculously flaky recently too imo, been doing download tests myself on the pc to determine download speeds.

Speedtest has been reporting anything from 16 Mbps to 26 Mbps and im getting download rates of 10MBps, big difference

[pgudge]

Thanks scaryjim, yeah, all test done on the same server.

I ran a iperf test and it appears to be giving me ~63Mb/s.

Chrome 18.0.1025.152 m, Firefox 11.0 and IE 9.0 all stop at about 40Mb/s! Maybe its Flash related, but the laptop and server are on the same Flash versions :-/

[pgudge]

Uninstalled Flash, and re-installed but still doesn't fix it. Other web speed tests also give me around 40Mb/s results, but jperf/iperf reports 65Mb/s. Java based speed tests also limited at ~40Mb/s.

iperf speeds between all machines goes no lower than 853 Mbits/sec

Any other ideas?

Thanks, PaulG.

[Zak33]

this is the kinds of issue that, from outside everyone says "stop worrying" but which I myself know would drive me mad... I'd be up all night trying to sort it, getting angry.

Do you have any antivirus or firewall differences on that PC? Is it scanning every packet?
Have you changed any of the network card settings?

Can you recall when it last ran fast properly? Last month? Is it worth going through Windows install history and see what you've changed/added?

I feel for you bud, really I do.....

[K3V]

give safe mode with networking a whirl, see if you get any different results

[Tifosi]

this would drive me up the wall too, some ideas

1. suggest you try benchmarking from a LiveCD to rule out the O/S
2. re run the benchmark on the native O/S and LiveCD over ethernet (if using wifi or powerline adaptors)
3. try dowloading a substantial file internally from your server to your desktop in native O/S and check you are getting the appropriate tx rates within your LAN
4. run the test with the other machines disconnected
5. check the duplex mode on the PC's network card
6. check QoS on your router (disable it?!)
7. check if the ethernet driver was updated recently
8. check if any other services in the background are downloading i.e. updates, p2p routing

[pgudge]

Do you have any antivirus or firewall differences on that PC? Is it scanning every packet?
Have you changed any of the network card settings?
Is it worth going through Windows install history and see what you've changed/added?

I feel for you bud, really I do.....

Thanks Zak33, it is bothering me a tad I am trialling a 80/20 service and they want regular speedtest, so I am having to remote home, then remote to another pc on the network to get a valid result. Nothing extra running on this desktop, I have removed everything that I installed/updated back to the date when I can see a speed drop, nothing!

give safe mode with networking a whirl, see if you get any different results

I will give that a try this evening. Thanks.

this would drive me up the wall too, some ideas

1. suggest you try benchmarking from a LiveCD to rule out the O/S
2. re run the benchmark on the native O/S and LiveCD over ethernet (if using wifi or powerline adaptors)
3. try dowloading a substantial file internally from your server to your desktop in native O/S and check you are getting the appropriate tx rates within your LAN
4. run the test with the other machines disconnected
5. check the duplex mode on the PC's network card
6. check QoS on your router (disable it?!)
7. check if the ethernet driver was updated recently
8. check if any other services in the background are downloading i.e. updates, p2p routing

1/2. Will try a Ubuntu LiveCD this evening, however see update below.
3. will run some test this evening, but all appears fine.
4/5/6/7/8. already tried/tested

Update! I fired up a Virtual Machine on my desktop and ran a speed test and achived 69Mbps :-/ So its not the network. I have changed network ports on the switch, received a new IP from the router, nothing fixes. It is as if there is something running telling it to only allow 40Mb

[Tifosi]

was the VM inside the host O/S, in which case I'd recommend running direct from a LiveCD the host O/S IP layer may be the issue.

[pgudge]

was the VM inside the host O/S, in which case I'd recommend running direct from a LiveCD the host O/S IP layer may be the issue.

Yeah, this machine is the VM Host. Guest was a Windows 2008 R2 install.