This is a problem that i observe regarding the Indicated wifi speed on the 'status' dialog box (Windows 7 operating System). I have a TP-Link wifi-n enabled router. The box indicates a connection spped / maximum speed of 150 Mbps(small b). on my status dialog i do see a speed of 150.0 Mbps listed. However on certain other PC's (All Win7) I see speeds as low as 5 Mbps. Why does this happen? How will this Affect performance? how may this be rectified.
Lots of external and internal variables affect wireless speeds.
First one that comes to mind are differences in wifi adapters. Are all machines using same model hardware? Are all using same driver version with exactly the same configs?
External factors include distance from AP, objects in between ap and laptop (walls, furniture, etc), external 'noise' sources (microwaves, other APs).
It depends upon how the access point / router is configured and how devices are connecting to it. From the speed mentioned, your A/P is an 802.11n device. It can also handle 802.11g and b (53mbps and 11mbps, or lower, depending upon device distrance from A/P-Router) devices. However, it will generally run at the speed of the slowest system connected. Also affecting speed are how many other routers or other devices in range are using the same channel (frequency) as your systems. If all of your devices are 802.11n, then go to the configuration page of the router and lock it into that protocol. When you do that, 802.11g/b devices won't work with it. If some are 802.11g, then configure the A/P to that - your 802.11n devices are backward compatible with that. If some are 802.11b only, then buy some new gear! :-)
So, first thing to try is changing the default channel (default is usually ch.6) - channels 1, 6, and 11 are (for 802.11g at least) are best, but mileage may vary. I generally use channel 11 at home for my 802.11g router since all the neighbors use the default channel 6 (they are not network experts, which I happen to be), and we usually have at least 6 devices connected to the WiFi (3-4 laptops, several phones, some ebook readers, and now tablets). They are all 802.11n/g devices and get good speed on the 802.11g router.
The second thing to try is to lock your router into 802.11g mode.
The third thing to try is to add a repeater access point at the other end of the house - distance and walls will attenuate the signal and slow things down considerably. We have two access points in our house, and there are areas where we need to switch from one to the other to get decent speed. I use a power-line ethernet device to connect the two A/Ps. Works as well as a hard wire between them, without the need to pull wiring through the walls! :-)
are you using a router that only transmit straight 802.11 or a mix of a/b as one of the previous poster sugget check ou PC cards if they are simmular.
also check your router config. is it config for 1 or multiple connection.