MSI GX620 has a 15.4 inch display and GX720 has a 17inch display. Interestingly the specification is same and they differ only in display size

GX620 / GX720 Specification and Features:

• Intel® Core™ 2 Duo Processor
• Intel®PM45 Chipset
• NVIDIA GeForce 9600M GT with 512MB DDR3 VRAM
• 4GB DDR2 @ 800MHz RAM
• Speakers: 2 (GX620) & 4+1 (GX720)
• 2 Megapixel webcam
• 56K Modem
• 10/100/1000 Ethernet
• Bluetooth
• 802.11 b/g/n wireless ethernet
• HDMI out
• 4 in 1 card reader
• mic in / headphone out
• 3 USB 2.0 ports
• 1 RJ11 / RJ45 ports
• 1 D-Sub port
• 1 E SATA port
• 320 GB SATA HDD
• DVD super multi / Bluray
• 6 Cell battery
• 103 keys keyboard
• 90W Power AC adapter

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