My PC is Windows 7 Ultimate N X64 Licensed. My MB is Gigabyte P55-US3L with 4 Gb Ram and Intel I5 CPU. Ethernet adapter is Realtek RTL8111D

 

I'm connected to the router by LAN and am only about 2 meter away from the router.

 

I notice that my speed to UK tested with testmy.net is only 7Mb and is very unstable. The graph looks like a mountain. Min speed ~3Mb - Max  speed ~17Mb.

 

When I test on my phone by wifi I get easily 14Mb same server and stable.

 

All other devices in the house ( 2 Android boxes and a PC) all connected by LAN, and much further away from the router, also get about 15Mb down same server.

 

I have reinstalled almost every driver version of the LAN adapter I can find on the web, but result doesn't change.

 

My son's PC has Windows 7 Ultimate N X86 installed, so I remove his disk and mount it in my PC. I don't install or reinstall any drivers or whatever, and get 16Mb down.

 

So I mount my disk again and install the same Realtek driver my son has on his OS, but still get only 6-7Mb

 

I mount a brand new disk in my PC and install a new Windows 7 Ultimate N x64 OS. I get again only 6-7 Mb down.

 

Next I reformat the disk and install Windows 7 Ultimate X86. Download speed is 6-7 Mb.

 

I remove the disk again and again mount the disk from my son's PC and Baaam, 16Mb down again.

 

Someone can explain what is going on here?

 

 

What about other online speed test sites? Same result?

I don't know, because in my opinion testmy.net is one of the only few reliable sites.

 

Ookla will use multithreads so result is always high.

What speed if the laptop is connected wifi, any different ?

start in safe with networking and see if any difference, then you know its a software issue. Maybe antivirus monitoring network connections, or you have some sort of Qos bandwidth manager running.

What about your disk in sons PC ? 

Have you done anything to the router, ie: port forwarding, static IP etc, to the MAC address of your PC 

1 hour ago, Peterw42 said:

What speed if the laptop is connected wifi, any different ?

start in safe with networking and see if any difference, then you know its a software issue. Maybe antivirus monitoring network connections, or you have some sort of Qos bandwidth manager running.

What about your disk in sons PC ? 

Have you done anything to the router, ie: port forwarding, static IP etc, to the MAC address of your PC 

 

Please read the OP again, it's all in there.

 

My son's harddisk mounted in my PC runs 17Mb down from London server on Testmy.net. And so do the 2 android boxes connected by LAN and the telephone connected by WIFI.

 

My son's harddisk in his PC connected by lan 15 meter from from the router also runs high download speed.

 

My OS in my pc runs about 7Mb from the same server.

 

I have so far used 2 new 2Tb disks and have installed 4 different OS on them, and they all get a download speed of 7Mb.

 

 

I have now also tried with Ookla speedtest as another postyer suggested, each time using the same London based server, and there are the test results between my son's disk and the other OS' comparable.

 

Though I get only around 8Mb on all OS, where on testmy.net I'll get +16Mb on my son's OS.

 

On Ookla my ping is ~380ms on all systems, while on Testmy.net the ping is ~260ms on all systems.

 

My router has only a static IP to my PC, all other IP addresses are controlled by DHCP.

 

 

 

 

Can you turn off the static IP etc, and retest, as that does appear to be the only common denominator. 

 

In the advanced settings for your Ethernet adaptor compare all the settings from your sons OS and your OS
Things like auto speed negotiating full/half duplex
There can be quite a few settings make sure they all exactly match in both OS
Change yours to match your sons

6 minutes ago, Peterw42 said:

Can you turn off the static IP etc, and retest, as that does appear to be the only common denominator. 

 

 

 

Without the static IP it's same, in fact I only set a static ip yesterday as I hoped it would improve.

I'm curious about which Thai ISP can provide a stable and prolonged 16mbs download from a UK server as none of the ones I have ever tried came anywhere close to that, unless perhaps you are paying extra for some "premium" connection. ISP name and type/cost of package, please.

 

I suspect that your PC is actually showing a real result and that all the others are showing incorrect or cached results.

48 minutes ago, KittenKong said:

I'm curious about which Thai ISP can provide a stable and prolonged 16mbs download from a UK server as none of the ones I have ever tried came anywhere close to that, unless perhaps you are paying extra for some "premium" connection. ISP name and type/cost of package, please.

 

I suspect that your PC is actually showing a real result and that all the others are showing incorrect or cached results.

 

3BB 18.8/1.8 ADSL

 

 

2 hours ago, Anthony5 said:

3BB 18.8/1.8 ADSL

 

Interesting. I have the same package but I dont get those results on a regular and prolonged basis.

 

The 30.99 reading on the second test is very suspect.

For quite a while I have considered testmy.net to be unreliable when gauging internet bandwidth from Thailand. Too often the results are erratic and not consistent with the real world experience.

 

Why are you concerned with bandwidth to the UK? Perhaps you are streaming from BBC iplayer/ITV etc?

 

If so, stop using VPN and switch to DNS proxy. According to the speedtest you posted above, you should have few problems.

Why I'm concerned with speeds to the UK? Probably because there is not a single website or server, other than Google and Facebook perhaps,  which I connect to that is located in Thailand.

 

Where did I make mention of a VPN used? If I was using a VPN my results would not show 3BB, is it?