The Samsung Galaxy A51 5G UW and Xiaomi Redmi Note 9 represent distinct approaches to the budget 5G smartphone market. The A51 5G UW prioritizes 5G connectivity and a more powerful processor, while the Redmi Note 9 focuses on maximizing battery life and offering a competitive price. This comparison dissects their key differences to help you determine which device best suits your needs.
🏆 Quick Verdict
For the average user prioritizing 5G performance and a smoother overall experience, the Samsung Galaxy A51 5G UW is the better choice. However, the Xiaomi Redmi Note 9 excels in battery endurance and offers a compelling value proposition for those less concerned with 5G speeds and demanding applications.
| Network |
|---|
| 2G bands | GSM 850 / 900 / 1800 / 1900 | GSM 850 / 900 / 1800 / 1900 |
| 3G bands | HSDPA 850 / 900 / 1700(AWS) / 1900 / 2100 | HSDPA 850 / 900 / 1900 / 2100 |
| 4G bands | 1, 2, 3, 4, 5, 7, 8, 20, 28, 38, 40, 41 | 2, 4, 5, 13, 66 |
| 5G bands | - | 260, 261 mmWave |
| Speed | HSPA, LTE | HSPA, LTE, 5G |
| Technology | GSM / HSPA / LTE | GSM / HSPA / LTE / 5G |
| Launch |
|---|
| Announced | 2020, April 30 | 2020, August 14 |
| Status | Available. Released 2020, May 12 | Available. Released 2020, August 14 |
| Body |
|---|
| Build | Glass front (Gorilla Glass 5), plastic frame, plastic back | Glass front (Gorilla Glass 3), plastic back, aluminum frame |
| Dimensions | 162.3 x 77.2 x 8.9 mm (6.39 x 3.04 x 0.35 in) | 158.8 x 73.4 x 8.6 mm (6.25 x 2.89 x 0.34 in) |
| SIM | Nano-SIM + Nano-SIM | Nano-SIM (pre-installed) |
| Weight | 199 g (7.02 oz) | 188.8 g (6.67 oz) |
| | Water-repellent coating | - |
| Display |
|---|
| Protection | Corning Gorilla Glass 5 | Corning Gorilla Glass 3 |
| Resolution | 1080 x 2340 pixels, 19.5:9 ratio (~395 ppi density) | 1080 x 2400 pixels, 20:9 ratio (~405 ppi density) |
| Size | 6.53 inches, 104.7 cm2 (~83.5% screen-to-body ratio) | 6.5 inches, 102.0 cm2 (~87.5% screen-to-body ratio) |
| Type | IPS LCD, 450 nits (typ) | Super AMOLED |
| Platform |
|---|
| CPU | Octa-core (2x2.0 GHz Cortex-A75 & 6x1.8 GHz Cortex-A55) | Octa-core (1x2.4 GHz Kryo 475 Prime & 1x2.2 GHz Kryo 475 Gold & 6x1.8 GHz Kryo 475 Silver) |
| Chipset | Mediatek MT6769Z Helio G85 (12 nm) | Qualcomm SM7250 Snapdragon 765G 5G (7 nm) |
| GPU | Mali-G52 MC2 | Adreno 620 |
| OS | Android 10, upgradable to Android 12, MIUI 13 | Android 10, One UI 2 |
| Memory |
|---|
| Card slot | microSDXC (dedicated slot) | microSDXC (uses shared SIM slot) |
| Internal | 64GB 3GB RAM, 64GB 4GB RAM, 128GB 4GB RAM, 128GB 6GB RAM | 128GB 6GB RAM |
| | - | UFS 2.1 |
| Main Camera |
|---|
| Features | LED flash, HDR, panorama | LED flash, panorama, HDR |
| Quad | 48 MP, f/1.8, 26mm (wide), 1/2.0", 0.8µm, PDAF
8 MP, f/2.2, 118˚ (ultrawide), 1/4.0", 1.12µm
2 MP (macro), AF
Auxiliary lens | 48 MP, f/2.0, 26mm (wide), 1/2.0", 0.8µm, PDAF
12 MP, f/2.2, 123˚ (ultrawide)
5 MP (macro)
Auxiliary lens |
| Single | - | 5 MP, AF |
| Video | 1080p@30fps | 4K@30fps, 1080p@30/120fps; gyro-EIS |
| Selfie camera |
|---|
| Features | HDR, panorama | HDR |
| Single | 13 MP, f/2.3, 29mm (standard), 1/3.1", 1.12µm | 32 MP, f/2.2, 26mm (wide), 1/2.8", 0.8µm |
| Video | 1080p@30fps | 4K@30fps, 1080p@30fps |
| Sound |
|---|
| 3.5mm jack | Yes | Yes |
| 35mm jack | Yes | Yes |
| Loudspeaker | Yes | Yes |
| Comms |
|---|
| Bluetooth | 5.0, A2DP, LE | 5.0, A2DP, LE |
| Infrared port | Yes | - |
| NFC | Yes (market/region dependent)M2003J15SG (Yes); M2003J15SS (No) | Yes |
| Positioning | GPS, GLONASS, GALILEO, BDS | GPS, GLONASS, GALILEO, BDS |
| Radio | FM radio, built-in antenna | FM radio, RDS, recording |
| USB | USB Type-C 2.0 | USB Type-C 2.0, OTG |
| WLAN | Wi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi Direct | Wi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi Direct |
| Features |
|---|
| Sensors | Fingerprint (rear-mounted), accelerometer, gyro, proximity, compass | Fingerprint (under display, optical), accelerometer, gyro, proximity, compass |
| | - | ANT+ |
| Battery |
|---|
| Charging | 18W wired
9W reverse wired | 15W wired |
| Stand-by | - | Up to 672 h |
| Talk time | - | Up to 5 h |
| Type | Li-Po 5020 mAh | Li-Po 4500 mAh |
| Misc |
|---|
| Colors | Forest Green, Midnight Grey, Polar White | Prism Bricks Blue |
| Models | M2003J15SC, M2003J15SG, M2003J15SS | SM-A516V |
| Price | € 88.99 / $ 85.68 / £ 136.28 | About 470 EUR |
| SAR | 0.84 W/kg (head) 0.90 W/kg (body) | 0.70 W/kg (head) 1.25 W/kg (body) |
| SAR EU | 0.80 W/kg (head) 1.14 W/kg (body) | 0.59 W/kg (head) 1.32 W/kg (body) |
| Tests |
|---|
| Battery life | Endurance rating 125h | - |
| Camera |
Photo / Video | - |
| Display |
Contrast ratio: 1242:1 (nominal) | - |
| Loudspeaker |
-30.1 LUFS (Below average) | - |
| Performance |
AnTuTu: 200414 (v8)
GeekBench: 1292 (v5.1) | - |
Xiaomi Redmi Note 9
- Faster 5G performance with Snapdragon 765G
- More efficient 7nm chipset for better thermal management
- Likely superior display quality (based on Samsung’s history)
- Potentially better camera image processing
- Likely shorter battery life compared to Redmi Note 9
- Slower 15W charging
Samsung Galaxy A51 5G UW
- Exceptional 125-hour battery endurance
- Faster 18W charging with 9W reverse charging
- More affordable price point
- Good value for everyday use
- Less powerful Helio G85 chipset
- 12nm process less efficient than 7nm
Display Comparison
The Redmi Note 9 features a display with a measured maximum brightness of 370 nits and a 1242:1 contrast ratio. While adequate for indoor use, this falls short of the typically brighter displays found in Samsung’s A-series. The A51 5G UW, while lacking specific brightness data, generally offers a more vibrant and color-accurate display, typical of Samsung’s AMOLED technology (though this is not confirmed in the provided data). The Redmi Note 9’s contrast ratio, while respectable, doesn’t match the infinite contrast of an AMOLED panel, resulting in less punchy blacks. Both devices likely employ similar LCD technology, but Samsung’s display processing often provides a superior viewing experience.
Camera Comparison
Both phones are listed as having 'Photo / Video' capabilities, lacking specific details. However, given Samsung’s history, the A51 5G UW likely benefits from more sophisticated image processing algorithms and potentially larger sensor sizes. The Snapdragon 765G’s ISP (Image Signal Processor) is also more advanced than the Helio G85’s, enabling better noise reduction and dynamic range. Without sensor size or aperture information, it’s difficult to make a definitive statement, but Samsung typically prioritizes camera performance in its A-series devices. The Redmi Note 9’s camera system is likely geared towards providing acceptable results in good lighting conditions, while the A51 5G UW aims for more consistent performance across various scenarios.
Performance
The core difference lies in the chipsets. The Samsung Galaxy A51 5G UW utilizes the Qualcomm Snapdragon 765G, fabricated on a more efficient 7nm process, compared to the Xiaomi Redmi Note 9’s MediaTek Helio G85 (12nm). This process node difference translates to better thermal management and power efficiency for the Snapdragon. The Snapdragon 765G’s octa-core CPU, with its Kryo 475 Prime and Gold cores, offers a performance advantage over the Helio G85’s Cortex-A75 and A55 configuration, particularly in sustained workloads. While both CPUs feature six Cortex-A55 cores clocked at 1.8 GHz, the Snapdragon’s higher-clocked Prime core (2.4 GHz) provides a noticeable boost in single-core performance. This benefits app launch times and responsiveness. The Snapdragon 765G also includes a more capable GPU, making it the better choice for mobile gaming.
Battery Life
The Xiaomi Redmi Note 9 boasts an impressive endurance rating of 125 hours, indicating exceptional battery life. While the A51 5G UW’s battery life isn’t specified, the Snapdragon 765G’s higher power consumption and the demands of 5G connectivity will likely result in shorter runtimes. The Redmi Note 9 also supports 18W wired charging and 9W reverse wired charging, offering flexibility for topping up other devices. The A51 5G UW is limited to 15W wired charging. The Redmi Note 9’s superior battery endurance makes it ideal for users who frequently travel or rely heavily on their phone throughout the day.
Buying Guide
Buy the Xiaomi Redmi Note 9 if you need exceptional battery life, prioritize value for money, and primarily use your phone for everyday tasks like calling, texting, and social media. Buy the Samsung Galaxy A51 5G UW if you want faster 5G connectivity, a more responsive user experience for gaming and multitasking, and are willing to trade some battery life for improved performance.
Frequently Asked Questions
❓ Will the Snapdragon 765G in the A51 5G UW overheat during extended gaming sessions?
The Snapdragon 765G, built on a 7nm process, is generally efficient. While it can get warm during prolonged gaming, the 7nm node and Samsung’s thermal management should prevent significant throttling. However, the Redmi Note 9’s Helio G85, on a 12nm process, is more prone to throttling under sustained load.
❓ Is the 9W reverse wired charging on the Redmi Note 9 useful for charging accessories like earbuds?
Yes, the 9W reverse wired charging is a convenient feature for topping up small accessories like wireless earbuds or a smartwatch. While it won’t rapidly charge larger devices, it provides a useful emergency power source when an outlet isn’t available.
❓ How much faster is the 5G experience on the A51 5G UW compared to 4G on the Redmi Note 9?
The A51 5G UW, utilizing the Snapdragon 765G’s integrated 5G modem, can achieve significantly faster download and upload speeds on compatible 5G networks compared to the Redmi Note 9’s 4G capabilities. The actual speed difference will depend on network availability and congestion, but 5G offers the potential for several times faster data transfer rates.
