Why is my MacBook Pro's internet speed so much slower than my iMac and iPhone while on same network in the same room?

Hold down the Option key while you click on the WiFi Icon on the menuBar. You get a report similar to this old one. From the report, post some numbers:

what do you get for PHY mode and channel?

what do you get for Tx rate, transmit rate?

what do you get for RSSI, signal strength or signal to noise?

and very important, how many other networks do you see?

.

I have a similar problem, so I followed the steps I saw in the replies here. The screenshot inserted here is taken while my Macbook Pro is inches away from the router, where it is still slow. I typically keep it in my room where, even though the RSSI is typically in the 50s, I have not speed issues like this in months. When my Macbook Pro has gotten slow like this, my iPhone is always putting up speeds 2 or 3 times faster in the same locations.

Any other recommendations?

Much obliged.

You have 90 less 30 or -60dB of signal, excellent signal.

Using 802.11n with a 40MHz channel, top baseband speed is probably 135, so you are using two antennas to get 270 transit rate. that may be as FAST as you can easily attain using 802.11n.

If you are not seeing good results, there may be other Networks interfering on channel 35.

¿How many other Networks do you see?

You can get a list of visible networks by center-channel using Network Diagnostics built-in tools, accessible from the Wireless Diagnostic menu.

choose Scan, and a list of visible networks will appear, with their center channels noted:

That display does not tell the whole story. When you use a particular nominal channel, your data actually use additional channels around the nominal channel. So another user on a nearby channel could be causing interference. This graph from Wi-Fi explorer, an inexpensive Utility with a three day trial, is MUCH more illustrative of what is actually happening, because its shows the signal spread:

Here you can see that the single Network nominally on channel 35 is putting out energy up to channel 50.

Many Routers can do "Automatic" channel selection. When set to automatic, your Router "sniffs" the channels, looking for one that is most lightly used, and chooses that channel at power-up. That is also why step 1 in debugging these issues is "cycle the power to your Router".

On channel 6 with a 20 MHz channel, the fastest baseband speed in probably 65MHz. To get your reported 130 Mbytes/sec, you are likely using two antennas.

80 noise less 68 signal leaves you only 12, poor reception. You are doing remarkably well to maintain your connection.

If you think there is possibly of a disconnected antenna, walk your computer within a few feet of the Router. RSSI (Signal) should improve to better than (closer to zero than) -50.

If you only see two other networks, then interference is not the issue, signal strength is the issue.

If you have three devices in that room, why not move the Router in there, and lengthen the phone line, cable, or wire that makes the connection to the Network. Or add another Router and an Ethernet connection between them.

The executive summary would be: Poor reception due to too far from Router.

Comparisons to other computers may be due to different Hardware. Also, the antennas are in the screen-surround on the MacBook Pro.