The maximum achievable speed for a laptop over a wireless connection can be determined by considering the specifications of the 802.11n wireless adapter and the network configuration. The 2x2 802.11n adapter and access point have two transmit and two receive antennas, allowing for up to two spatial streams. The wireless network uses a 40 MHz wide channel, allowing for a higher data rate than a 20 MHz wide channel. The maximum data rate per spatial stream in 802.11n is 300 Mbps per channel. Combining the number of spatial streams and the maximum data rate per stream, the maximum achievable speed is 600 Mbps. Therefore, the maximum achievable speed for a laptop over this wireless connection is 600 Mbps.