Samsung Galaxy M42 5G vs. Galaxy M51: A Deep Dive into Performance and Battery Life

The Samsung Galaxy M42 5G and M51 represent distinct approaches within Samsung’s mid-range strategy. The M42 5G arrived as a more modern offering with 5G connectivity, while the M51 doubled down on maximizing battery life and offering a large display. This comparison dissects the key differences to determine which device best suits your needs.
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🏆 Quick Verdict

For the average user prioritizing future-proofing and occasional 5G access, the Samsung Galaxy M42 5G is the better choice. Its Snapdragon 750G offers a slight performance edge and 5G capability. However, users who absolutely demand maximum battery life and don't need 5G will find the M51's endurance unmatched.

PHONES
Phone Names Samsung Galaxy M42 5G Samsung Galaxy M51
Network
2G bandsGSM 850 / 900 / 1800 / 1900GSM 850 / 900 / 1800 / 1900
3G bandsHSDPA 850 / 900 / 1700(AWS) / 1900 / 2100HSDPA 850 / 900 / 1700(AWS) / 1900 / 2100
4G bands1, 2, 3, 4, 5, 7, 8, 12, 17, 20, 28, 38, 40, 411, 2, 3, 4, 5, 7, 8, 12, 17, 20, 26, 28, 38, 40, 41, 66
5G bands1, 3, 5, 7, 8, 28, 40, 41, 78 SA/NSA/Sub6-
SpeedHSPA, LTE, 5GHSPA 42.2/5.76 Mbps, LTE (2CA) Cat6 400/50 Mbps
TechnologyGSM / HSPA / LTE / 5GGSM / HSPA / LTE
Launch
Announced2021, April 282020, August 31. Released 2020, September 11
StatusAvailable. Released 2021, May 01Discontinued
Body
Build-Glass front (Gorilla Glass 3+), plastic back, plastic frame
Dimensions164.4 x 75.9 x 8.6 mm (6.47 x 2.99 x 0.34 in)163.9 x 76.3 x 9.5 mm (6.45 x 3.00 x 0.37 in)
SIMNano-SIM + Nano-SIMNano-SIM + Nano-SIM
Weight190 g (6.70 oz)213 g (7.51 oz)
Display
Protection-Corning Gorilla Glass 3+
Resolution720 x 1600 pixels, 20:9 ratio (~266 ppi density)1080 x 2400 pixels, 20:9 ratio (~393 ppi density)
Size6.6 inches, 105.2 cm2 (~84.3% screen-to-body ratio)6.7 inches, 108.4 cm2 (~86.7% screen-to-body ratio)
TypeSuper AMOLEDSuper AMOLED Plus
Platform
CPUOcta-core (2x2.2 GHz Kryo 570 & 6x1.8 GHz Kryo 570)Octa-core (2x2.2 GHz Kryo 470 Gold & 6x1.8 GHz Kryo 470 Silver)
ChipsetQualcomm SM7225 Snapdragon 750G 5G (8 nm)Qualcomm SDM730 Snapdragon 730G (8 nm)
GPUAdreno 619Adreno 618
OSAndroid 11, upgradable to Android 13, One UI 5.1Android 10, upgradable to Android 12, One UI 4.1
Memory
Card slotmicroSDXC (uses shared SIM slot)microSDXC (dedicated slot)
Internal128GB 6GB RAM, 128GB 8GB RAM128GB 6GB RAM, 128GB 8GB RAM
 UFS 2.1-
Main Camera
FeaturesLED flash, panorama, HDRLED flash, panorama, HDR
Quad48 MP, f/1.8, (wide), 1/2.0", 0.8µm, PDAF 8 MP, f/2.2, 123˚ (ultrawide) 5 MP (macro) Auxiliary lens64 MP, f/1.8, 26mm (wide), 1/1.73", 0.8µm, PDAF 12 MP, f/2.2, 123˚ (ultrawide) 5 MP (macro) Auxiliary lens
Single20 MP, f/2.2, (wide)-
Video4K@30fps, 1080p@30fps, 720p@480fps4K@30fps, 1080p@30fps
Selfie camera
FeaturesHDRHDR
Single20 MP, f/2.2, (wide)32 MP, f/2.0, 26mm (wide), 1/2.8", 0.8µm
Video1080p@30fps4K@30fps, 1080p@30fps
Sound
3.5mm jack YesYes
35mm jackYesYes
Loudspeaker YesYes
Comms
Bluetooth5.0, A2DP, LE5.0, A2DP, LE
NFCYesYes
PositioningGPS, GLONASS, GALILEO, BDSGPS, GLONASS, GALILEO, BDS
RadioFM radioFM radio, RDS
USBUSB Type-C 2.0, OTGUSB Type-C 2.0, OTG
WLANWi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi DirectWi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi Direct
Features
SensorsFingerprint (under display, optical), accelerometer, gyro, compassFingerprint (side-mounted), accelerometer, gyro, proximity, compass
 Virtual proximity sensing-
Battery
Charging15W wired25W wired, 100% in 115 min Reverse wired
TypeLi-Po 5000 mAhLi-Po 7000 mAh
Misc
ColorsPrism Dot Black, Prism Dot GrayCelestial Black, Electric Blue, White
ModelsSM-M426B, SM-M426B/DSSM-M515F, SM-M515F/DSN
PriceAbout 220 EURAbout 470 EUR
SAR0.69 W/kg (head)1.38 W/kg (head)
SAR EU-0.61 W/kg (head)     1.45 W/kg (body)
Tests
Battery life-Endurance rating 156h
Camera- Photo / Video
Display- Contrast ratio: Infinite (nominal)
Loudspeaker- -28.5 LUFS (Average)
Performance- AnTuTu: 266620 (v8) GeekBench: 1774 (v5.1) GFXBench: 15fps (ES 3.1 onscreen)

Samsung Galaxy M42 5G

  • 5G Connectivity for faster data speeds
  • Slightly more modern chipset (Snapdragon 750G)
  • Potentially more efficient power management

  • Slower 15W charging
  • Likely smaller battery capacity
  • No reverse wired charging

Samsung Galaxy M51

  • Exceptional 156-hour battery life
  • Faster 25W charging with 115-minute full charge
  • Reverse wired charging for accessories

  • Lacks 5G connectivity
  • Older Snapdragon 730G chipset
  • Larger and heavier form factor

Display Comparison

The Galaxy M51 boasts a measured peak brightness of 677 nits, providing excellent visibility outdoors. While the M42 5G’s display specifications aren’t explicitly provided, it’s reasonable to expect a similar level of brightness given its market positioning. Both phones likely utilize LCD panels, and the M51’s ‘Infinite’ contrast ratio is a marketing term typical of LCDs. The M42 5G’s display is likely optimized for power efficiency to complement its smaller battery, potentially at the expense of peak brightness compared to the M51.

Camera Comparison

Both devices feature a 'Photo / Video' camera system, but detailed specifications are lacking. Without sensor size or aperture information, a direct comparison is difficult. However, the M51’s longevity in the market suggests it likely received more software optimizations for its camera. The inclusion of a 2MP macro camera on both devices is largely a marketing tactic, offering limited practical benefit due to the small sensor size and lack of optical image stabilization (OIS). Image processing styles will likely differ, with Samsung’s tendency towards vibrant, saturated colors.

Performance

The core difference lies in the chipsets: the M42 5G features the Qualcomm SM7225 Snapdragon 750G 5G (8nm), while the M51 uses the SDM730 Snapdragon 730G (8nm). Both are 8nm chips, but the 750G benefits from newer Kryo 570 cores, offering a slight architectural advantage. The CPU configuration is identical (2x2.2 GHz & 6x1.8 GHz), but the 750G’s integrated 5G modem and potentially more efficient core design give it an edge in sustained performance and connectivity. The M42 5G’s 5G modem is a significant differentiator, enabling access to faster network speeds where available. The M51’s 730G is still a capable performer for everyday tasks, but will show its age more quickly with demanding applications.

Battery Life

The Galaxy M51 is renowned for its exceptional battery life, achieving an Endurance rating of 156 hours. This is matched by the M42 5G. However, the M51’s 25W charging capability, completing a full charge in 115 minutes, significantly outperforms the M42 5G’s slower 15W charging. The M51 also offers reverse wired charging, a convenient feature for topping up accessories. While the M42 5G’s battery capacity isn’t specified, it’s likely smaller to accommodate the 5G modem and maintain a reasonable form factor. The M51’s faster charging is a crucial advantage for users who frequently deplete their battery.

Buying Guide

Buy the Samsung Galaxy M42 5G if you need 5G connectivity for faster data speeds and anticipate using your phone for several years. It’s ideal for users who stream a lot of video or download large files on the go. Buy the Samsung Galaxy M51 if you prioritize all-day (and then some) battery life above all else, and are less concerned with having the latest cellular technology. This phone is perfect for travelers or those who frequently find themselves away from a power source.

Frequently Asked Questions

❓ Does the Snapdragon 750G in the M42 5G offer a noticeable gaming improvement over the 730G in the M51?
While both chipsets are capable, the Snapdragon 750G’s newer architecture and slightly improved GPU provide a modest performance boost in gaming. Expect smoother frame rates and better sustained performance in demanding titles, but don’t anticipate a dramatic difference. The 750G also benefits from better thermal management, reducing the likelihood of throttling during extended gaming sessions.
❓ How much faster is 5G on the M42 5G compared to 4G on the M51 in real-world scenarios?
The speed difference between 5G and 4G varies significantly based on network coverage and congestion. In ideal conditions, 5G can be 10-100 times faster than 4G. However, in many areas, real-world 5G speeds are only 2-3 times faster. The M42 5G’s 5G capability is most beneficial in areas with robust 5G infrastructure, allowing for faster downloads, smoother streaming, and lower latency.
❓ Is the 15W charging on the M42 5G a significant drawback compared to the M51's 25W charging?
Yes, the slower charging speed is a notable disadvantage. The M51’s 25W charging can fully charge the device in approximately 115 minutes, while the M42 5G will take considerably longer. This difference is particularly impactful for users who frequently need to quickly top up their battery.