| Samsung Rex 90 | Samsung SGH-X640 |
| Manufacture | Samsung | Samsung |
| Model | Rex 90 | SGH-X640 |
| Form factor | Block | Block |
| Weight | 0 gram | 85.00 |
| Dimensions (HxWxD) | 113 x 61.9 x 11.84 | 87.00 x 47.00 x 23.00 |
| Operating System | Other | Other |
| Networks | 2G - 850/900/1800/1900 | 2G - 900/1800/1900 |
| HSCSD |  | |
| GPRS |  | |
| EDGE | | |
| UMTS | | |
| HSDPA | | |
| HSPA+ | | |
| WiMAX | | |
| LTE (4G light) | | |
| WLAN / Wi-Fi | | |
| Wi-Fi Hotspot | | |
| Wi-Fi Direct | | |
| SMS | | |
| MMS | | |
| | |
| HDMI out | | |
| USB port | | |
| MHL | | |
| Bluetooth | | |
| Bluetooth version | 3.0 | NA |
| DLNA | | |
| GPS | | |
| Glonass | | |
| ANT+ | | |
| IrDA | | |
| NFC | | |
| 3.5 mm audio connector | | |
| Camera | | |
| Camera resolution | 3.2 megapixel | 0.3 Megapixels (640x480), 4x digital zoom |
| Image Stabilization | | |
| BSI sensor | | |
| Camera Flash/Light | | |
| Flash type | NA | NA |
| Video recording | | |
| Video capture resolution | NA | NA |
| Second Camera | NA | NA |
| Display size | 3.5 inches | 0.00 |
| Touchscreen | | |
| Colour display | | |
| Number of colours | NA | 65000 |
| Display width | 320 | 128 |
| Display height | 480 | 160 |
| PPI | 164.83 | NA |
| Second Display | NA | NA |
| CPU | NA | NA |
| GPU | NA | NA |
| Memory | 10 MB user memory. Expandable using microSD card | 9.5 MB |
| Micro SIM | | |
| Dual SIM | | |
| MP3 | | |
| Ringtones / Music file format | MP3, AAC, AAC+, eAAC+, MIDI, SP-Midi, AMR, WAV | Polyphonic 40 voices |
| Java | | |
| Games | NA | 2 |
| FM Radio | | |
| Battery | 1000 mAh | NA |
| Standby time (h) | NA | 220 |
| Talktime (m) | NA | 210 |
| Wireless Charging | | |
| Browser | Opera Mini. NetFront Access | 2.0 |
| Calendar | | |
| Voicedialing | | |
| IP Code | NA | NA |
| Predictive text | | |
| RSS reader | | |
| Voicememo | | |
| PC Synchronization | | |
| SyncML | | |
| Website | Website | Website |