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I have a Dell Inspirion 5520 that has Intel(R) Centrino(R) Wireless-N 2230 built in.

Also I have a TP link TL-WR740N wireless router.

I have an 80Mbps/25MBps internet connection.

My Speedtest result with no router:

enter image description here

When I connect all these via an Ethernet cable, I get the maximum even through the router:

enter image description here

But when I try to do the same with WiFi I get 30/20 Maximum speed, and I'm sitting next to router!

I have this configuration:

- Channel: auto
- Mode: 11n only
- Channel width: 40Mhz
- Max Tx rate: 150Mbps
- Enabled Wireless Router Radio
- Enabled SSID Broadcast
- Security: WPA- AES
- Beacon Interval : 100
- RTS Threshold: 2346
- Fragmentation Threshold: 2346
- DTIM Interval: 1
- Enabled WMM
- Enabled Short GI

Intel(R) Centrino(R) Wireless-N 2230:
- 802.11n Channel width for band 2.4 : Auto
- 802.11n Mode: enabled
- Ad Hoc Channel 802.11b/g: 1
- Ad Hoc QoS Mode: WMM enabled
- Bluetooth(R) AMP: Enabled
- Fat Channel Intolerant: Disabled
- Mixed Mode Protection: CTS-to-self Enabled - Roaming Aggressiveness: 3. Medium - Transit power: 5. Highest - Wireless Mode: 802.11b/g

I do get the fact that speed through wireless is slower than with wire, but losing 50Mbps is a bit too much!

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up vote 4 down vote accepted
  1. Disable Bluetooth on the Centrino 2230.
  2. And also set Bluetooth(R) AMP: Disabled.
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thanks! this made it work! I would have not guessed that the bluetooth would interfere this much! – NaGeL182 Mar 7 '13 at 22:29
how comes enabling/disabling bluetooth effects wifi transfer that much? – Yevgeniy M. Aug 2 '13 at 21:09
I thnink it's because both Bluetooth and wifi operate in the range of 2400–2483.5 MHz. So this causes interference with each other. Your microwave could also be interfering(if poorly shielded) ... see: Electromagnetic_interference_at_2.4_GHz – Robb Aug 29 '13 at 22:36

Having G devices on your network can slow down the speed for all devices. Encryption, distance and interface can also limit your speed.

SmallNetBuilder has a couple of good articles on steps you can try:

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I'm the only one on the router currently, and i read those articles, sadly didn't help. – NaGeL182 Mar 3 '13 at 21:20

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