Physical Competition: Lumia 820 has a width of 9.9 mm while 620 has a 11mm width making 820 much thinner than 620. 820 has a gyroscope, a device that is used to maintain or measure the orientation of the device which is useful in gaming applications etc but 620 plus these feature. The Specific Absorption Rate (SAR) gives the amount of radio frequency that passes through a human body.820 has a 0.79 W/kg SAR and 620 has 0.84 W/kg SAR. That means 820 emits 0.5 W/kg SAR than 620 and is friendlier for human health. 820 has a smaller semi conductor size than 620 indicating that the technology used in making 820’s chips is newer than that of 620. 620 is about 8.4 mm shorter than 820 it is 33 g lighter in weight with 620’s weight being 127 g and 820’s 160 g. 620 is 7.4 mm narrower than 820.
Display: Lumia 820 has a screen size of 4.3 inches with 620’s screen size being 3.8 inches. This makes 820 more appealing in comparison to 620 when it comes to better and larger viewing. 620 has a better image view as it has more pixels and sub pixels than 820. 620 has 246 ppi pixels with 820 having only 217 ppi which makes Lumia 620 give more crispier image than Lumia 820.
Memory, Camera and CPU: Lumia 820 has a RAM of 1 GB while 620 has a RAM of only 512 MB, giving 820 an upper hand. B20 has faster CPU speed as it has 1.5 GHz while 620 has only 1 GHz. Lumia 820 has a manual exposure system that allows the user to manually set the exposure settings. It has a flash system with dual LEDs that give a brighter flash. During movie or video recording, auto focus feature ensures that the resulting video has a clear and sharp output. Lumia 820 comes with 8 Mega Pixels while Lumia 620 has a camera of only 5 MP. The lenses used in 820 are branded while Lumia 620 does not have branded lenses and the movie recording is better in 820 than 620.
Other Features: Lumia 820 can be wirelessly charged like electronic toothbrushes and it has more battery life than Lumia 620. 820 has better and faster downloading speed. 820 has a download speed of 100 MBits/s with 620 only having a speed of 21 MBits/s. even their uploading speed has a difference with 820 being 8.68 times faster than 620. 820 has a newer Bluetooth version which is 3.1 with 620’s 3.0 and 820 has a radio while 620 does not. So, 820 beats 620 in every aspect.