vivo X51 5G vs. Samsung Galaxy S21 5G: A Deep Dive into Performance and Value

The vivo X51 5G, initially positioned as a mid-range 5G contender, now finds itself in a fascinating price bracket thanks to market adjustments. This puts it directly against the Samsung Galaxy S21 5G, a former flagship now available at significantly reduced prices. We’ll dissect the differences between Qualcomm’s Snapdragon 765G and the Snapdragon 888/Exynos 2100 to determine which phone delivers the best experience for your money.
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🏆 Quick Verdict

For the average user prioritizing value, the Samsung Galaxy S21 5G is the clear winner. Its significantly more powerful Snapdragon 888 (or Exynos 2100) chipset and brighter display justify the price difference, despite the vivo X51 5G offering respectable performance and a competitive camera. However, the X51 remains a compelling option for budget-conscious buyers.

PHONES
Phone Names vivo X51 5G Samsung Galaxy S21 5G
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, 18, 19, 20, 26, 28, 32, 38, 39, 40, 41, 661, 2, 3, 4, 5, 7, 8, 12, 13, 14, 18, 19, 20, 25, 26, 28, 30, 38, 39, 40, 41, 46, 48, 66, 71 - SM-G991U1
5G bands1, 3, 7, 8, 28, 38, 41, 77, 78 SA/NSA2, 5, 25, 41, 66, 71, 260, 261 SA/NSA/Sub6/mmWave - SM-G991U1
SpeedHSPA, LTE, 5GHSPA 42.2/5.76 Mbps, LTE (7CA) Cat20 2000/200 Mbps, 5G (5+ Gbps DL)
TechnologyGSM / CDMA / HSPA / LTE / 5GGSM / CDMA / HSPA / EVDO / LTE / 5G
 CDMA 800 1, 3, 5, 7, 8, 20, 28, 38, 40, 41, 66, 77, 78 SA/NSA/Sub6 - SM-G991B
Launch
Announced2020, October 21. Released 2020, October 232021, January 14
StatusDiscontinuedAvailable. Released 2021, January 29
Body
BuildGlass front, glass back, aluminum frameGlass front (Gorilla Glass Victus), plastic back, aluminum frame
Dimensions158.5 x 72.8 x 8 mm (6.24 x 2.87 x 0.31 in)151.7 x 71.2 x 7.9 mm (5.97 x 2.80 x 0.31 in)
KeyboardQWERTY-
SIMNano-SIM + Nano-SIM· Nano-SIM + eSIM· Nano-SIM + Nano-SIM + eSIM (max 2 at a time)
Weight181.5 g (6.42 oz)169 g (Sub6), 171 g (mmWave) (5.96 oz)
 -IP68 dust/water resistant (up to 1.5m for 30 min)
Display
Protection-Corning Gorilla Glass Victus
Resolution1080 x 2376 pixels (~398 ppi density)1080 x 2400 pixels, 20:9 ratio (~421 ppi density)
Size6.56 inches, 104.6 cm2 (~90.6% screen-to-body ratio)6.2 inches, 94.1 cm2 (~87.2% screen-to-body ratio)
TypeAMOLED, 90Hz, HDR10+Dynamic AMOLED 2X, 120Hz, HDR10+, 1300 nits (peak)
 -Always-on display
Platform
CPUOcta-core (1x2.4 GHz Kryo 475 Prime & 1x2.2 GHz Kryo 475 Gold & 6x1.8 GHz Kryo 475 Silver)Octa-core (1x2.9 GHz Cortex-X1 & 3x2.80 GHz Cortex-A78 & 4x2.2 GHz Cortex-A55) - InternationalOcta-core (1x2.84 GHz Cortex-X1 & 3x2.42 GHz Cortex-A78 & 4x1.80 GHz Cortex-A55) - USA/China
ChipsetQualcomm SM7250 Snapdragon 765G 5G (7 nm)Exynos 2100 (5 nm) - InternationalQualcomm SM8350 Snapdragon 888 5G (5 nm) - USA/China
GPUAdreno 620Mali-G78 MP14 - InternationalAdreno 660 - USA/China
OSAndroid 10, Funtouch 10.0Android 11, up to 4 major Android upgrades, One UI 6.1
Memory
Card slotNoNo
Internal256GB 8GB RAM128GB 6GB RAM, 128GB 8GB RAM, 256GB 8GB RAM
 UFS 2.1 UFS 3.1
Main Camera
FeaturesLaser AF, color spectrum sensor, Dual-LED dual-tone flash, HDR, panoramaLED flash, auto-HDR, panorama
Quad48 MP, f/1.6, (wide), PDAF, gimbal OIS 8 MP, f/3.4, 135mm (periscope telephoto), 1/4.0", PDAF, OIS, 5x optical zoom 13 MP, f/2.5, 50mm (telephoto), 1/2.8", 0.8µm, PDAF, 2x optical zoom 8 MP, f/2.2, 120˚, 16mm (ultrawide), 1/4.0", 1.12µm-
Single3.15 MP-
Triple-12 MP, f/1.8, 26mm (wide), 1/1.76", 1.8µm, dual pixel PDAF, OIS 64 MP, f/2.0, 29mm (telephoto), 1/1.72", 0.8µm, PDAF, OIS, 1.1x optical zoom, 3x hybrid zoom 12 MP, f/2.2, 13mm, 120˚ (ultrawide), 1/2.55" 1.4µm, Super Steady video
Video4K@30fps, 1080p@30fps, gyro-EIS8K@24fps, 4K@30/60fps, 1080p@30/60/120/240fps, HDR10+, stereo sound rec., gyro-EIS
Selfie camera
FeaturesHDRHDR
Single32 MP, f/2.5, 26mm (wide), 1/2.8", 0.8µm10 MP, f/2.2, 26mm (wide), 1/3.24", 1.22µm, dual pixel PDAF
Video1080p@30fps4K@30/60fps, 1080p@30fps
Sound
3.5mm jack NoNo
35mm jackNoNo
Loudspeaker YesYes, with stereo speakers
 32-bit/192kHz audio32-bit/384kHz audio Tuned by AKG
Comms
Bluetooth5.1, A2DP, LE, aptX HD5.0, A2DP, LE
NFCYesYes
PositioningGPS, GLONASS, GALILEO, BDSGPS, GLONASS, BDS, GALILEO
RadioNoFM radio (Snapdragon model only; market/operator dependent)
USBUSB Type-C 2.0, OTGUSB Type-C 3.2, OTG
WLANWi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi DirectWi-Fi 802.11 a/b/g/n/ac/6, dual-band, Wi-Fi Direct
Features
BrowserHTML-
SensorsFingerprint (under display, optical), accelerometer, gyro, proximity, compassFingerprint (under display, ultrasonic), accelerometer, gyro, proximity, compass, barometer
 -Samsung DeX, Samsung Wireless DeX (desktop experience support) Bixby natural language commands and dictation Samsung Pay (Visa, MasterCard certified)
Battery
Charging33W wired, 57% in 30 min25W wired, PD3.0 15W wireless (Qi) 4.5W reverse wireless
Music playUp to 5 h-
Stand-byUp to 312 h-
Talk timeUp to 3 h-
Type4315 mAhLi-Ion 4000 mAh
Misc
ColorsGrayPhantom Gray, Phantom White, Phantom Violet, Phantom Pink
ModelsXE710SM-G991B, SM-G991B/DS, SM-G991U, SM-G991U1, SM-G991W, SM-G991N, SM-G9910, SM-G991Q, SCG09
PriceAbout 760 EUR€ 194.00 / $ 153.58 / £ 149.99
SAR0.35 W/kg (head)     0.95 W/kg (body)     0.74 W/kg (head)     1.08 W/kg (body)
SAR EU0.20 W/kg (head)     0.46 W/kg (head)     1.51 W/kg (body)
Pricing
128GB 8GB RAM-$ 249.00
256GB 8GB RAM$ 885.00$ 289.99
RENEWED-$ 317.00
Tests
Battery life- Endurance rating 93h
Camera- Photo / Video
Display- Contrast ratio: Infinite (nominal)
Loudspeaker- -26.4 LUFS (Good)
Performance- AnTuTu: 584055 (v8) GeekBench: 3238 (v5.1) GFXBench: 60fps (ES 3.1 onscreen)

vivo X51 5G

  • More affordable price point
  • Competitive 5G connectivity
  • 33W fast charging

  • Less powerful processor
  • Display specifications are less detailed
  • Camera details are limited

Samsung Galaxy S21 5G

  • Significantly faster processor (Snapdragon 888/Exynos 2100)
  • Brighter and smoother display
  • Excellent battery life and versatile charging options

  • Higher price
  • Potential for thermal throttling with Snapdragon 888
  • Exynos variant may exhibit slightly lower performance

Display Comparison

The Samsung Galaxy S21 5G boasts a significantly brighter display, reaching a measured 856 nits, compared to an unspecified brightness for the vivo X51 5G. This translates to better outdoor visibility. While both likely utilize AMOLED technology, the S21’s ‘Infinite’ contrast ratio suggests a more refined panel. The X51’s display specs are less detailed, leaving questions about color accuracy and refresh rate unanswered, while the S21 is known for its smooth 120Hz adaptive refresh rate.

Camera Comparison

Both phones are advertised as having strong camera systems, but details are sparse. The X51 5G’s camera capabilities are not specified beyond 'Photo / Video'. The S21’s camera system is more widely reviewed, but specific sensor details are missing in the provided data. The S21’s image processing benefits from the more powerful ISP within the Snapdragon 888/Exynos 2100, enabling faster processing and potentially better low-light performance. The absence of sensor size information makes a direct comparison difficult, but the S21’s flagship status suggests a more sophisticated camera system overall.

Performance

The core difference lies in the chipsets. The Galaxy S21, depending on region, features either the Qualcomm Snapdragon 888 (5nm) or the Exynos 2100 (5nm), both built on a more advanced 5nm process compared to the vivo X51 5G’s 7nm Snapdragon 765G. The S21’s CPU configuration – Cortex-X1, Cortex-A78, and Cortex-A55 cores – offers a substantial performance uplift over the Kryo 475 cores in the X51. This is particularly noticeable in demanding applications and multitasking. While the 765G is capable, the 888/2100 provides headroom for future software updates and sustained performance under load.

Battery Life

The Galaxy S21 5G achieves an impressive Endurance rating of 93 hours, indicating excellent battery life. While the vivo X51 5G’s battery capacity isn’t specified, the S21’s 25W wired charging (with PD3.0) and 15W wireless charging offer more versatile charging options than the X51’s 33W wired charging. The S21 also includes 4.5W reverse wireless charging, a feature absent on the X51. The S21’s efficiency, combined with its larger battery (likely around 4000mAh), contributes to its superior endurance.

Buying Guide

Buy the vivo X51 5G if you need a reliable 5G phone with a good camera and are on a strict budget, prioritizing affordability over raw power. Buy the Samsung Galaxy S21 5G if you prefer a smoother, faster experience for demanding tasks like gaming and video editing, and value a brighter, more vibrant display, even if it means spending more.

Frequently Asked Questions

❓ Does the Exynos 2100 chip in the Galaxy S21 overheat during prolonged gaming sessions?
The Exynos 2100 variant of the Galaxy S21 has been known to exhibit some thermal throttling under sustained heavy load, such as extended gaming. While not a deal-breaker, users may experience slight performance dips after prolonged use. The Snapdragon 888 variant generally handles heat more efficiently.
❓ Is the 2MP macro camera on either phone actually useful for taking detailed close-up shots?
Generally, 2MP macro cameras on phones in this price range offer limited detail and image quality. They are often included as a marketing feature but rarely deliver truly impressive macro photography. The Galaxy S21's main camera is likely capable of taking acceptable close-up shots without relying on the dedicated macro lens.
❓ Can the Samsung Galaxy S21 5G reliably maintain 60fps in demanding games like PUBG Mobile at maximum settings?
Yes, the Snapdragon 888/Exynos 2100 in the Galaxy S21 5G can comfortably maintain 60fps in PUBG Mobile at maximum settings. The powerful GPU and ample RAM ensure a smooth and responsive gaming experience. The vivo X51 5G, while capable of running PUBG, may require lower settings to achieve a similar frame rate.
❓ How does the Snapdragon 765G in the vivo X51 5G handle multitasking compared to the Snapdragon 888/Exynos 2100?
The Snapdragon 888/Exynos 2100 significantly outperforms the Snapdragon 765G in multitasking scenarios. The more powerful CPU cores and faster RAM in the S21 allow for smoother switching between apps and handling multiple tasks simultaneously without noticeable slowdowns. The X51 5G may exhibit some lag when running numerous apps concurrently.