T-Mobile Sidekick 4G vs ZTE X990

Compare recorded specifications, size and practical differences.

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Key differences

Calculated from recorded specifications using minimum difference thresholds. These are differences, not an overall ranking. For three phones, numeric highlights compare the two extremes.

  • Weight

    X990: 72 g lighter

    Sidekick 4G:
    162 g
    X990:
    90 g
  • Screen diagonal

    X990: 1 in smaller diagonal

    Sidekick 4G:
    3.5 in
    X990:
    2.5 in
  • Depth

    X990: 3 mm thinner

    Sidekick 4G:
    15 mm
    X990:
    12 mm
  • Height

    X990: 20 mm shorter

    Sidekick 4G:
    127 mm
    X990:
    107 mm
  • Release year

    Sidekick 4G:
    2011
    X990:
    2010

Physical size

Relative size, not calibrated actual size. Front and side outlines share one scale and a bottom baseline. Generic outlines use recorded body dimensions, excluding camera bumps.

  1. 1. Sidekick 4G

    Height:
    127 mm +20 mm versus X990
    Width:
    61 mm
    Depth:
    15 mm +3 mm versus X990
  2. 2. X990

    Height:
    107 mm
    Width:
    61 mm
    Depth:
    12 mm

Weight

Bars start at zero and share a scale within this chart.

  1. 1. Sidekick 4G

    162 g

    +72 g versus X990

  2. 2. X990

    90 g

Screen size

Approximate rectangular screens calculated from recorded diagonal and aspect ratio at one relative scale. Rounded corners and cutouts are not subtracted. These are not phone outlines or calibrated actual sizes.

  1. 1. Sidekick 4G

    Screen diagonal:
    3.5 in
    Aspect ratio (height:width):
    5:3
    Approximate rectangular screen area:
    34.9 cm²
  2. 2. X990

    Screen diagonal:
    2.5 in
    Aspect ratio (height:width):
    4:3
    Approximate rectangular screen area:
    19.4 cm²

Sidekick 4G has approximately 80.1% more rectangular screen area than X990.

Memory variants

Each row compares the same storage capacity. Cells show recorded RAM alternatives, not combined maxima. Not recorded does not mean unavailable in every market.

No unambiguous storage/RAM pairings are recorded. See the original specifications below.

Sidekick 4G: Original memory entry

1 GB · 512 MB RAM

X990: Original memory entry

5 MB

Practical features

Explicit Yes and No values are shown directly. Qualified or regional records retain their details. Unknown means the record is missing.

1. Sidekick 4G

NFC:
Unknown
Headphone jack:
Yes
Memory card support:
See details microSD · up to 32 GB (dedicated slot) · 2 GB included

2. X990

NFC:
Unknown
Headphone jack:
No
Memory card support:
See details microSD · up to 8 GB (dedicated slot)

Battery capacity

Capacity is not battery life. No endurance test is implied.

At least two unambiguous positive capacity values are needed for a chart. Original entries remain in the specifications.

Specifications

Open a section for more detail. On narrow screens, swipe sideways or use Left/Right arrow keys while the table is focused. Unknown means missing data, not No. Recorded zero values are shown as recorded.

1. Sidekick 4G2. X990

Everyday essentials
Everyday essentials — specifications for Sidekick 4G, X990.
SpecificationSidekick 4GX990
Dimensions (HxWxD)
  • 127 Х 61 Х 15 mm
  • 107 Х 61 Х 12 mm
Weight
  • 162 g
  • 90 g
Technology
  • TFT
  • TFT
Screen size
  • 3.5" inch
  • 2.5" inch
Screen resolution
  • 480 x 800 px
  • 320 x 240 px
Internal memory Recorded storage / RAM variants. Entries are alternatives, not a combined maximum. Ambiguous formats stay as recorded.
  • 1 GB
  • 512 MB RAM
  • 5 MB
Memory card support
  • microSD
  • up to 32 GB (dedicated slot)
  • 2 GB included
  • microSD
  • up to 8 GB (dedicated slot)
Battery Capacity is not battery life. No endurance test is implied.
  • 1500 mAh
  • Removable Li-Ion
  • 0 mAh,
Operating system OS
  • Android 2.2 (Froyo)
  • Microsoft Windows Mobile 6.5 Professional
Chipset
  • Hummingbird
Unknown
Headphone jack
  • Yes
  • No
Display
Display — specifications for Sidekick 4G, X990.
SpecificationSidekick 4GX990
Touchscreen
  • capacitive touchscreen
  • resistive touchscreen
Display colors
  • 16M
  • 256K
Screen area
  • 34.9 cm2
  • 19.4 cm2
Screen format
  • 5:3 (height:width)
  • 4:3 (height:width)
Screen to body ratio
  • 45.0%
  • 29.7%
PPI /points per inch/
  • 267 PPI
  • 160 PPI
Camera and Video
Camera and Video — specifications for Sidekick 4G, X990.
SpecificationSidekick 4GX990
Rear camera, main
  • 3.15 MP
  • Single
  • 2 MP
  • Single
Camera specs
  • 3.15 MP
  • AF
  • 2 MP
Video
  • 480p@30fps
  • Yes
Front camera, selfie
  • 0.3 MP
  • Single
  • 0 MP,
Specifications
  • VGA
Unknown
Performance
Performance — specifications for Sidekick 4G, X990.
SpecificationSidekick 4GX990
Processor CPU
  • 1.0 GHz Cortex-A8
Unknown
Graphics processor GPU
  • PowerVR SGX540
Unknown
General specs
General specs — specifications for Sidekick 4G, X990.
SpecificationSidekick 4GX990
Release date
  • 2011
  • March
  • 2010
  • March
Colors
  • Matte Black
  • Pearl magenta
  • White
Historical recorded price Legacy catalogue value; date unknown. Not a current offer.
  • 310 EUR
Unknown
Battery life
  • Stand by time- Up to 456 h Talking time- Up to 6 h 30 min
  • Stand by time- Up to 480 h Talking time- Up to 8 h
Communication and Connectivity
Communication and Connectivity — specifications for Sidekick 4G, X990.
SpecificationSidekick 4GX990
SIM card
  • Mini-SIM
  • Mini-SIM
Network
  • Show all network frequencies: -2G - GSM 850 / 900 / 1800 / 1900
Unknown
Speed
  • HSPA 7.2/5.76 Mbps
Unknown
GPRS
  • Yes
  • Class 10
Edge
  • Yes
  • Class 10
Wi-Fi
  • Wi-Fi 802.11 b/g/n
  • DLNA
  • hotspot
  • No
GPS
  • Yes
  • with A-GPS
  • No
USB
  • microUSB 2.0
  • microUSB 2.0
Bluetooth
  • 3.0
  • A2DP
  • 2.0
  • A2DP
Harmful irradiation
  • SAR - 0.34 W/kg (head) 0.96 W/kg (body)
  • SAR EU - 0.96 W/kg (head)
Music and Audio
Music and Audio — specifications for Sidekick 4G, X990.
SpecificationSidekick 4GX990
Radio
  • Nо
  • Stereo FM radio
  • RDS
Other features
Other features — specifications for Sidekick 4G, X990.
SpecificationSidekick 4GX990
Dop
  • Sensors Accelerometer
  • proximity - T-Mobile TV -MP4/H.264 player -MP3/WAV/eAAC+ player -Organizer -ThinkFree Office document editor
  • PDF viewer -Voice memo -Predictive text input - Optical trackpad - Also known as T-Mobile T839 Sidekick 4G
  • Windows Live Messenger -MP3/WMA/eAAC+ player -MP4/H.264 player -MS Office -Organizer -Voice memo -Predictive text input Also known as Messenger by SFR 251 Edition