Xiaomi 15 Ultra vs Samsung Galaxy S25 Ultra: A Battle of Endurance and Speed

The Xiaomi 15 Ultra and Samsung Galaxy S25 Ultra represent the pinnacle of Android smartphone technology, both powered by the latest Qualcomm Snapdragon 8 Elite. However, they diverge significantly in their approach to battery life, charging speeds, and display characteristics, creating a clear choice for users prioritizing different aspects of the mobile experience.
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🏆 Quick Verdict

For the average user, the Xiaomi 15 Ultra emerges as the winner. Its dramatically superior battery endurance (58:58h vs 44:54h) and significantly faster charging (90W wired, 80W wireless) outweigh the Galaxy S25 Ultra’s brighter display, making it the more practical choice for power users.

PHONES
Phone Names Xiaomi 15 Ultra Samsung Galaxy S25 Ultra
Network
2G bandsGSM 850 / 900 / 1800 / 1900GSM 850 / 900 / 1800 / 1900
3G bandsHSDPA 800 / 850 / 900 / 1700(AWS) / 1900 / 2100HSDPA 850 / 900 / 1700(AWS) / 1900 / 2100
4G bands1, 2, 3, 4, 5, 7, 8, 12, 13, 17, 18, 19, 20, 25, 26, 28, 32, 38, 39, 40, 41, 42, 48, 66, 71 - International1, 2, 3, 4, 5, 7, 8, 12, 13, 17, 18, 19, 20, 25, 26, 28, 32, 38, 39, 40, 41, 66 - International
5G bands1, 2, 3, 5, 7, 8, 12, 20, 25, 26, 28, 38, 40, 41, 48, 66, 71, 75, 77, 78, 79 SA/NSA - International1, 2, 3, 5, 7, 8, 12, 20, 25, 26, 28, 38, 40, 41, 66, 75, 77, 78 SA/NSA/Sub6 - International
SpeedHSPA, LTE, 5GHSPA, LTE (up to 7CA), 5G
TechnologyGSM / HSPA / LTE / 5GGSM / CDMA / HSPA / EVDO / LTE / 5G
Launch
Announced2025, February 272025, January 22
StatusAvailable. Released 2025, February 27Available. Released 2025, February 03
Body
BuildGlass front, fiber-reinforced plastic back or silicone polymer back (eco leather), aluminum frameGlass front (Corning Gorilla Armor 2), glass back (Gorilla Glass Victus 2), titanium frame (grade 5)
Dimensions161.3 x 75.3 x 9.4 mm (6.35 x 2.96 x 0.37 in)162.8 x 77.6 x 8.2 mm (6.41 x 3.06 x 0.32 in)
SIM· Nano-SIM + Nano-SIM· Nano-SIM + Nano-SIM + eSIM + eSIM (max 2 at a time)· Nano-SIM + Nano-SIM + eSIM + eSIM (max 2 at a time) - INT· Nano-SIM + eSIM + eSIM (max 2 at a time) - USA· Nano-SIM + Nano-SIM - CN
Weight226 g or 229 g (7.97 oz)218 g (7.69 oz)
Display
ProtectionXiaomi Shield Glass 2.0, Mohs level 6Corning Gorilla Armor 2, Mohs level 6
Resolution1440 x 3200 pixels, 20:9 ratio (~522 ppi density)1440 x 3120 pixels, 19.5:9 ratio (~498 ppi density)
Size6.73 inches, 108.9 cm2 (~89.7% screen-to-body ratio)6.9 inches, 116.9 cm2 (~92.5% screen-to-body ratio)
TypeLTPO AMOLED, 68B colors, 120Hz, 1920Hz PWM, Dolby Vision, HDR10+, HDR Vivid, 3200 nits (peak)Dynamic LTPO AMOLED 2X, 120Hz, HDR10+, 2600 nits (peak)
Platform
CPUOcta-core (2x4.32 GHz Oryon V2 Phoenix L + 6x3.53 GHz Oryon V2 Phoenix M)Octa-core (2x4.47 GHz Oryon V2 Phoenix L + 6x3.53 GHz Oryon V2 Phoenix M)
ChipsetQualcomm SM8750-AB Snapdragon 8 Elite (3 nm)Qualcomm SM8750-AC Snapdragon 8 Elite (3 nm)
GPUAdreno 830Adreno 830 (1200 MHz)
OSAndroid 15, up to 4 major Android upgrades, HyperOS 2Android 15, up to 7 major Android upgrades, One UI 7
Memory
Card slotNoNo
Internal256GB 12GB RAM, 512GB 16GB RAM, 1TB 16GB RAM256GB 12GB RAM, 512GB 12GB RAM, 1TB 12GB RAM, 1TB 16GB RAM
Main Camera
FeaturesLaser AF, color spectrum sensor, Leica lenses, Dual-LED flash, HDR, panorama, 67mm filter ring holder (optional)Laser AF, Best Face, LED flash, auto-HDR, panorama
Quad50 MP, f/1.6, 23mm (wide), 1.0"-type, 1.6µm, dual pixel PDAF, OIS 50 MP, f/1.8, 70mm (telephoto), 1/2.51", 0.7µm, dual pixel PDAF (10cm - ∞), OIS, 3x optical zoom 200 MP, f/2.6, 100mm (periscope telephoto), 1/1.4", 0.56µm, multi-directional PDAF, OIS, 4.3x optical zoom 50 MP, f/2.2, 14mm, 115˚ (ultrawide), 1/2.76", 0.64µm, dual pixel PDAF TOF 3D, (depth)200 MP, f/1.7, 24mm (wide), 1/1.3", 0.6µm, multi-directional PDAF, OIS 10 MP, f/2.4, 67mm (telephoto), 1/3.52", 1.12µm, PDAF, OIS, 3x optical zoom 50 MP, f/3.4, 111mm (periscope telephoto), 1/2.52", 0.7µm, PDAF, OIS, 5x optical zoom 50 MP, f/1.9, 120˚ (ultrawide), 1/2.5", 0.7µm, dual pixel PDAF, Super Steady video
Video8K@30fps, 4K@30/60/120fps, 1080p@30/60/120/240/480/960/1920fps, gyro-EIS, Dolby Vision HDR 10-bit rec. (4K@60fps, 1080p)8K@24/30fps, 4K@30/60/120fps, 1080p@30/60/120/240fps, 10-bit HDR, HDR10+, stereo sound rec., gyro-EIS
Selfie camera
FeaturesHDR, panoramaHDR, HDR10+
Single32 MP, f/2.0, 21mm (wide), 1/3.14", 0.7µm12 MP, f/2.2, 26mm (wide), 1/3.2", 1.12µm, dual pixel PDAF
Video4K@30/60fps, 1080p@30/60fps, gyro-EIS4K@30/60fps, 1080p@30fps
Sound
35mm jackNoNo
Loudspeaker Yes, with stereo speakersYes, with stereo speakers
Comms
Bluetooth6.0, A2DP, LE, aptX HD, aptX Adaptive, LHDC 55.4, A2DP, LE
Infrared portYes-
NFCYesYes
PositioningGPS (L1+L5), BDS (B1I+B1c+B2a), GALILEO (E1+E5a), QZSS (L1+L5), NavIC (L5), GLONASSGPS, GLONASS, BDS, GALILEO, QZSS
RadioNoNo
USBUSB Type-C 3.2 Gen 2, DisplayPort, OTGUSB Type-C 3.2, DisplayPort 1.2, OTG
WLANWi-Fi 802.11 a/b/g/n/ac/6e/7, dual-band or tri-band, Wi-Fi DirectWi-Fi 802.11 a/b/g/n/ac/6e/7, tri-band, Wi-Fi Direct
Features
SensorsFingerprint (under display, ultrasonic), accelerometer, proximity, gyro, compass, barometerFingerprint (under display, ultrasonic), accelerometer, gyro, proximity, compass, barometer
Battery
Charging90W wired, PD3.0, QC3+ 80W wireless 10W reverse wireless45W wired, PD3.0, 65% in 30 min 15W wireless (Qi2 Ready) 4.5W reverse wireless
TypeMarket-dependent versions:· Si/C Li-Ion 5410 mAh - Global· Si/C Li-Ion 6000 mAh - ChinaLi-Ion 5000 mAh
Misc
ColorsBlack, White, Silver Chrome, GreenTitanium Silver Blue, Titanium Black, Titanium White Silver, Titanium Gray, Titanium Jade Green, Titanium Jet Black, Titanium Pink Gold
Models25010PN30GSM-S938B, SM-S938B/DS, SM-S938U, SM-S938U1, SM-S938W, SM-S938N, SM-S9380, SM-S938E, SM-S938E/DS
Price$ 1,328.84 / £ 889.00 / € 1,099.00€ 895.00 / $ 859.98 / £ 799.99 / ₹ 110,498
SAR-1.26 W/kg (head)     0.64 W/kg (body)
SAR EU1.00 W/kg (head)     1.00 W/kg (body)1.25 W/kg (head)     1.42 W/kg (body)
EU LABEL
Battery58:58h endurance, 1000 cycles44:54h endurance, 2000 cycles
EnergyClass AClass B
Free fallClass C (90 falls)Class A (270 falls)
RepairabilityClass CClass C

Xiaomi 15 Ultra

  • Exceptional battery endurance (58:58h)
  • Ultra-fast charging speeds (90W wired, 80W wireless)
  • Versatile reverse wireless charging (10W)

  • Display brightness not specified, potentially lower than Samsung
  • Camera specs unknown, making a direct comparison difficult

Samsung Galaxy S25 Ultra

  • High peak display brightness (1417 nits)
  • Qi2 wireless charging support
  • Potentially longer battery lifespan (2000 cycles)

  • Significantly lower battery endurance (44:54h)
  • Slower charging speeds (45W wired, 15W wireless)

Display Comparison

The Samsung Galaxy S25 Ultra boasts a measured peak brightness of 1417 nits, a substantial advantage for outdoor visibility compared to the Xiaomi 15 Ultra (brightness data not provided). While the Xiaomi 15 Ultra’s panel technology isn’t specified, Samsung’s likely implementation of LTPO technology allows for dynamic refresh rate scaling, potentially improving efficiency. However, the practical benefit of the higher brightness is diminished for indoor users, and the lack of detailed Xiaomi display specs makes a definitive judgment difficult.

Camera Comparison

Camera specifications are not provided beyond the device names. However, given Samsung’s history, the S25 Ultra likely features a versatile multi-camera system with a focus on high-resolution sensors and advanced image processing. Xiaomi has been increasingly competitive in camera performance, and the 15 Ultra likely offers a compelling alternative. Without detailed sensor size, aperture, and OIS information, a direct comparison is impossible, but we can expect both to deliver flagship-level image quality.

Performance

Both devices are powered by the Qualcomm SM8750-AC/AB Snapdragon 8 Elite (3nm) featuring an octa-core CPU configuration with 2x Oryon V2 Phoenix L cores at 4.32/4.47 GHz and 6x Oryon V2 Phoenix M cores at 3.53 GHz. The S25 Ultra’s slightly higher clock speed on the prime cores suggests a marginal performance advantage in single-threaded tasks, but real-world differences will likely be minimal. Both utilize LPDDR5x RAM (spec not provided, but standard for this class), and thermal management will be crucial to sustaining peak performance; the 3nm process should aid in this regard.

Battery Life

The Xiaomi 15 Ultra’s 58:58h endurance rating significantly surpasses the Samsung Galaxy S25 Ultra’s 44:54h. This difference is further amplified by the charging speeds: 90W wired, 80W wireless, and 10W reverse wireless for the Xiaomi, versus 45W wired, 15W wireless (Qi2 Ready), and 4.5W reverse wireless for the Samsung. The Xiaomi 15 Ultra can achieve a full charge much faster, and its wireless charging is nearly six times quicker. The S25 Ultra’s 2000 battery cycles suggest improved longevity, but the initial endurance advantage of the Xiaomi is substantial.

Buying Guide

Buy the Xiaomi 15 Ultra if you need all-day battery life and the fastest possible charging speeds, minimizing downtime. This phone is ideal for travelers, content creators, and anyone who heavily uses their smartphone throughout the day. Buy the Samsung Galaxy S25 Ultra if you prioritize a brighter display for outdoor visibility and are willing to trade some battery endurance for that feature. It’s a strong choice for media consumption and photography in bright sunlight.

Frequently Asked Questions

❓ How much faster is the Xiaomi 15 Ultra's charging compared to the Galaxy S25 Ultra?
The Xiaomi 15 Ultra's 90W wired charging is more than double the speed of the Galaxy S25 Ultra's 45W wired charging. Similarly, the Xiaomi's 80W wireless charging is almost six times faster than the Samsung's 15W wireless charging. This translates to significantly less time tethered to a charger.
❓ Does the Snapdragon 8 Elite in the Galaxy S25 Ultra overheat during prolonged gaming sessions?
The Snapdragon 8 Elite's 3nm process should improve thermal efficiency compared to previous generations. However, sustained peak performance will still generate heat. Samsung's thermal management system will be critical in preventing throttling, but without testing, it's difficult to predict how it will perform under heavy load. The Xiaomi 15 Ultra will face similar thermal challenges.
❓ What is the practical benefit of the Galaxy S25 Ultra's 2000 battery cycles?
The 2000 battery cycle rating suggests the S25 Ultra's battery will retain a higher percentage of its original capacity after a longer period of use compared to the Xiaomi 15 Ultra's 1000 cycles. This means the S25 Ultra's battery health will degrade more slowly over time, potentially extending its usable lifespan.
❓ Is the reverse wireless charging on the Xiaomi 15 Ultra useful for charging accessories like earbuds?
Yes, the Xiaomi 15 Ultra's 10W reverse wireless charging is sufficient for slowly topping up accessories like wireless earbuds or smartwatches. While not as fast as dedicated chargers, it provides a convenient way to share power on the go.