This is ridiculous!
Things I have tried so far and failed:
1. Switching ON/OFF HT Mode
2. USB Power mode
3. PCI Power mode
4. Disable Power Management
5. Bandwidth 40 to 20
6. Force G mode (cannot even hold 56mbps)
7. Switching Channels
8. Changing drivers, and updating to the latest version
I am not sure what else is there for me to try...
Forgot to add this: I have Samsung Ativ Book 9 Plus (NP940X3G) with Intel Wireless N 7260 Dual Band.
Nexus 5, Galaxy Note 3, Galaxy Note 2, Dell Venue 8 Pro, iPad Air, Macbok Air 2013, Retina Macbook Pro 2012, all of which without Intel Wireless work fine with the very same router at 50mbps/50mbps. This laptop slows down to 1mbps for no apparent reason and stuck at that.