Vivo X300 Ultra vs Xiaomi 14 Ultra

Vivo X300 Ultra

A 6.82-inch 144Hz LTPO AMOLED, now flat rather than quad-curved. Lab measurements put real brightness near 1,900 nits in auto and ~3,300 nits on a small window — among the best panels on any phone — and reviewers single out content consumption and clarity as standouts.

• We measured a maximum of over 1,900 nits in auto-brightness mode and over 3,300 nits when lighting up a smaller portion of the screen.
• Consuming content, scrolling the web, pixel-peeping and zooming in on text — it doesn't get any clearer, or with the 144Hz any smoother, than the display on the X300 Ultra.
• It delivers an excellent max brightness of around 1,935 nits with a 75% white pattern and a peak of 3,328 nits with a 10% pattern.
• Vivo has gone with a flat display this time, a clear shift from the quad-curved style of the X200 Ultra.
• It's a 6.82-inch AMOLED with a claimed 4,500-nit HDR peak that can reach that figure in a one-person window watching HDR content; PWM sits around 3.5% at max brightness, better for flicker-sensitive users.
• An absolutely stunning display with terrific, bass-heavy stereo speakers to match.

Xiaomi 14 Ultra

A 6.73-inch 2K LTPO AMOLED with 120Hz, 1920Hz PWM dimming, Dolby Vision and a 3,000-nit peak — a top-tier panel, though measured sustained brightness is good rather than class-leading.

• LTPO AMOLED, 68B colors, 120Hz, 1920Hz PWM, Dolby Vision, HDR10+, 1,000 nits typical / 3,000 nits peak.
• Peak brightness rose from 2,600 to 3,000 nits versus the 13 Ultra; the measured 1,281 nits isn't industry-leading but is excellent nonetheless.
• Notebookcheck's overall verdict scores it 'very good (89%)' — a 6.73-inch 3200×1440 panel among the best flagships.

Vivo X300 Ultra

Snapdragon 8 Elite Gen 5 plus Vivo's custom imaging silicon delivers flagship benchmark numbers and strong gaming, but the camera-heavy hardware runs hot — sustained stress tests show roughly 60–65% stability and the camera app warms it up fast.

• At the heart is Qualcomm's current flagship Snapdragon 8 Elite Gen 5, supplemented by Vivo's custom VS1 and V3-Plus imaging chips.
• It boots in 16 seconds (vs 21s for the S26 Ultra and 19s for the iPhone 17 Pro Max) and posts an AnTuTu score over 3,800,000, stronger than Samsung.
• In a prolonged stress test it throttled CPU performance to about 60% of peak — in line with other high-powered flagships — and 3DMark stability landed around 63–66%.
• It gets a bit hot after 30–40 minutes of gaming, but with no throttling even past an hour and never uncomfortable to hold; boost mode at max graphics gives around 4 hours of Wuthering Waves on a full charge.
• Native 120fps gaming with smooth/very-high graphics in many titles, with temperature barely crossing 35°C and power draw around 4W in battle-royale modes.
• Under sustained camera/imaging load the front reached ~46.8°C and the back ~45.2°C, and around 47°C the refresh rate drops slightly though not all the way to 60Hz.

Xiaomi 14 Ultra

Snapdragon 8 Gen 3 with Adreno 750 and up to 512GB UFS 4.0 puts it among the fastest 2024 flagships, with Xiaomi's IceLoop cooling keeping sustained gaming temperatures in check.

• Snapdragon 8 Gen 3 with Adreno 750 and 512GB UFS 4.0 — Notebookcheck rates it 'very good (89%)' overall.
• It's the reason it makes complete sense to put it against the best flagships — a phone that delivers on all fronts.
• Some camera lag appears only in dimly lit auto-mode scenes — raising EV and adjusting exposure in pro mode cuts it down significantly.

Vivo X300 Ultra

Vivo grew the silicon-carbon cell 10% to 6,600mAh while keeping the body the same size. Real-world endurance is strong — ~16h active-use score, ~7h heavy screen-on, 13–14 hour days with charge to spare — and 100W wired refills it in under an hour, with 40W wireless.

• Vivo increased the battery by 10% to 6,600mAh despite the phone being practically the same size on paper.
• In our battery test it earned an active-use score of almost 16 hours; 100W charging took it 0–66% in 30 minutes and a full charge in 46 minutes, plus 40W wireless. A charger is in the box except in Europe.
• On the China version I'm finishing entire 13–14 hour days with 25–30% left; the global version keeps the 6,600mAh cell so battery life should comfortably last 12–13 hours of heavy use.
• Getting nearly 7 hours of screen-on time with very heavy usage from the 6,600mAh silicon-carbon unit, with 100W wired and 40W wireless charging support.
• After a 4-hour heavy-usage simulation the phone still had ~45% battery left, which is solid by today's standards, and 100W wired charging takes about 45 minutes to full.
• In a head-to-head charge race against the Oppo Find X9 Ultra (80W), the Vivo on 100W finished first at 50 minutes 20 seconds to the Oppo's 52:39.

Xiaomi 14 Ultra

A 5,000mAh cell (global) with very fast 90W wired / 80W wireless charging. Endurance is improved over the 13 Ultra but still only middling for the class, and heavy gaming drains it quickly.

• The global Xiaomi 14 Ultra has a 5,000mAh battery — same capacity as the 13 Ultra — and endurance is a step up but doesn't win hearts.
• The biggest improvement is gaming endurance — up 33% over the 13 Ultra's underwhelming 5 hours, no longer miles behind competitors but still not class-leading.
• Charging: 90W wired fills empty-to-full in ~33 minutes (matched in testing), plus 80W wireless to 100% in ~46 minutes and 10W reverse wireless.
• Owners are 'not disappointed' with daily battery life, though some wish screen-on time were a bit better.