Mars rover data transmission:
The data rate direct-to-Earth varies from about 500 bits per second to 32,000 bits per second (roughly half as fast as a standard home modem).
The data rate to the Mars Reconnaissance Orbiter is selected automatically and continuously during communications and can be as high as 2 million bits per second.
The data rate to the Odyssey orbiter is a selectable 128,000 or 256,000 bits per second (4-8 times faster than a home modem). MSL: Data Rates/Returns
Read the rest of this short article. The transmission speed from Mars to Earth is better than in many rural areas here in Germany.