Choosing between OnePlus and Xiaomi in 2021 is not just a matter of preference, but a strategic decision about which technologies and ecosystem you like best: Both brands offer top-end devices with advanced features, but they are suitable for different categories of users, some value pure Android and maximum performance, and others value innovative cameras and rich functionality for less money.
In this comparison, we will analyze the key models of 2021: OnePlus 9 Pro and Xiaomi Mi 11 Ultra, as well as consider mid-budget options like OnePlus Nord 2 and Xiaomi Poco F3.
It’s worth noting that 2021 was a watershed year for both brands: OnePlus integrated with Oppo, which influenced its development strategy, and Xiaomi for the first time came out on top in the world in terms of smartphone sales, which could not but affect the final products – and not always for the better.
1. Performance and iron: who is faster in 2021?
In 2021, both manufacturers equipped their flagships with the top-end Qualcomm Snapdragon 888 chipset, but the implementation of cooling and software optimization played a crucial role. OnePlus 9 Pro is traditionally famous for its smooth interface thanks to the proprietary shell OxygenOS, which is closer to the “naked” Android. At the same time, the Xiaomi Mi 11 Ultra uses MIUI 12.5 – a more loaded shell with additional functions, but also with noticeable lags at a long load.
Tests show that in synthetic benchmarks (such as AnTuTu or Geekbench 5), the difference is minimal – both smartphones score about 800,000 points. However, in real-world scenarios, OnePlus benefits from better thermal throttle: in long-term games (Genshin Impact, Call of Duty Mobile), the processor frequency drops on the Mi 11 Ultra more strongly, which leads to FPS drawdowns.
- 🔥 OnePlus 9 Pro: stable 60 FPS permit-play 1440p, but warms to 43.°C.
- ❄️ Xiaomi Mi 11 Ultra: Peak 120 FPS into PUBG Mobile, but after 20 minutes, it will sink to 40. FPS.
- 🛠️ Mid-budget models: Poco F3 (Snapdragon 870 beats OnePlus Nord 2 (MediaTek Dimensity 1200) in multithreaded tasks.
⚠️ Warning: If you plan to use your smartphone to stream games via Xbox Cloud Gaming or GeForce NOW, keep in mind that MIUI It can block the background activity of applications, which causes a connection to break.
2.Screens: 120Hz vs 120Hz, but with nuances
Both flagships 2021 year AMOLED-refresh-frequency screens 120 Hz, but the technology is different. - OnePlus 9 Pro uses the LTPO-Samsung panel that adapts the frequency of the 1 Hz 120 Hz, depending on the content. It saves battery power and makes scrolling more smooth. 11 Ultra standard AMOLED fixed-mode 60/120 Hz – less energy efficient but with higher peak brightness (1700 baldness 1500 OnePlus).
Both screens scored high in color reproduction tests (DisplayMate A+), but Xiaomi has taken the lead with support for 10-bit color and factory calibration for DC Dimming mode (less flicker at low brightness). OnePlus offers a finer color profile setting through the Settings menu → Screen → Color mode.
| Parameter | OnePlus 9 Pro | Xiaomi Mi 11 Ultra |
|---|---|---|
| Screen technology | LTPO AMOLED, 6.7" | AMOLED, 6.81" |
| Adaptive frequency | 1-120 Hz | 60/120 Hz (fixed) |
| Peak brightness | 1,500 nits | 1700 nits |
| Support for HDR | HDR10+, Dolby Vision | HDR10+, Dolby Vision, HDR Vivid |
Critical nuance: the Mi 11 Ultra in the 120 Hz mode turns off adaptive brightness - this forces the user to manually adjust the backlight or put up with increased battery consumption.
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To enable DC Dimming mode on Xiaomi Mi 11 Ultra, go to Settings → Screen → Reading mode and activate the “No flicker” option.
3.Cameras: Hasselblad vs Leica (but not quite)
In 2021, OnePlus announced a partnership with Hasselblad, and Xiaomi continued to develop its own processing algorithms. On paper, the Mi 11 Ultra looks like the winner: 50 MP main sensor (Samsung GN2) with a pixel size of 1.4 microns, 48 MP super-wide and 48 MP periscopic telephoto lens (120× zoom). OnePlus 9 Pro has a more modest 48 MP main (Sony IMX789), 50 MP super-wide and 8 MP telephoto lens (3.3× zoom).
However, in real-world conditions, OnePlus often gets better thanks to more natural color reproduction and fewer artifacts when shooting in HDR. For example, in tests DXOMark (2021), the OnePlus 9 Pro received 122 points against 143 from the Mi 11 Ultra, but users note that photos on Xiaomi often look “recycled” – especially in Night Mode.
- 📸 OnePlus 9 Pro: Best Details in Daytime Scenes, Natural Colors.
- 🌙 Mi 11 Ultra: record night mode, but with excessive noise cancellation.
- 🎥 Video: Both filming 8K@30fps, Xiaomi supports Dolby Vision HDR right in the cell.
⚠️ Note: When shooting a video in 8K Mi 11 Ultra disables stabilization - this makes the frames shivering. OnePlus 9 Pro keeps hybrid stabilization even in the 8K.
How to turn off watermarks in the photo in MIUI?
4.Software: OxygenOS vs MIUI 12.5
The difference is fundamental. OnePlus’s OxygenOS is the closest shell to pure Android 11, with a minimum of pre-installed apps and an intuitive interface. MIUI 12.5 is a full-fledged ecosystem with a bunch of features, but also with aggressive background optimization that kills apps (for example, Telegram or WhatsApp may not receive notifications).
The advantages of OxygenOS:
- ⚡ Quick security updates (monthly).
- 🔄 Minimalist design without unnecessary animations.
- 🔓 No bootloader lock (easier to get root).
The benefits of MIUI 12.5 are:
- 🎯 Extended gestures (e.g. Double touch to block).
- 🔒 Built-in App Lock and Second Space (Dual OS).
- 🌐 Support for design themes and icons.
Key fact: In 2021, OnePlus began integrating elements of ColorOS (Oppo shells) into OxygenOS, which caused discontent among fans of the brand. For example, OnePlus Nord 2 introduced a duplicate menu Optimized Launch, as in Oppo.
☑️ How to Prepare Xiaomi for the First Setup
5. Battery and charging: speed vs capacity
In 2021, Xiaomi set a record for charging speed: the Mi 11 Ultra supports 67W wired and 67W wireless charging, which allows you to charge the battery 4500 mAh to 100% in 36 minutes. OnePlus 9 Pro lags behind: 4500 mAh, but only 65W wired and 50W wireless charging (full charge in 43 minutes).
However, in tests of autonomy OnePlus was more effective: thanks to adaptive screen and optimization of OxygenOS, it holds the charge 15-20% longer under mixed load.
- OnePlus 9 Pro: 12 hours 30 minutes.
- Mi 11 Ultra: 10 hours 15 minutes.
⚠️ Note: Wireless charging on the Mi 11 Ultra requires a branded Xiaomi Wireless Charger station (worth it) ~5000 ₽). Charging from third-party devices is limited 10W.
| Parameter | OnePlus 9 Pro | Xiaomi Mi 11 Ultra |
|---|---|---|
| Battery capacity | 4500 mAh | 5,000 mAh |
| Wire-based charging | 65W (Warp Charge) | 67W (HyperCharge) |
| Wireless charging | 50W | 67W |
| Reverse charging | No. | 10W |
6. Design and ergonomics: glass vs ceramics
The Xiaomi Mi 11 Ultra became the first mass-produced smartphone with a ceramic body - a material stronger than glass but heavier (the device weighs 234g). The rear panel is made in the style of Leica with a massive chamber module that protrudes at 5mm and makes the phone unstable on the table. the OnePlus 9 Pro is lighter (197g) and thinner, but its glass rear panel is more slipper and less scratch resistant.
Both smartphones have IP68 protection, but Xiaomi has a unique feature: a secondary display on the camera module (1.1 inches), which shows notifications, time or is used as a view camera for selfies by the main module. OnePlus does not have this, but its screen is curved on the sides (3D Corning Gorilla Glass), which visually makes the device thinner.
- 🏆 OnePlus 9 Pro: more compact, more comfortable in the hand.
- 🎨 Mi 11 Ultra: Premium ceramic case, but uncomfortable chamber module.
- 🔧 Repairability: OnePlus is easier to replace the screen (price) ~15 000 ₽ vs ~25 000 ₽ Xiaomi).
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If you drop your phone frequently, go for the OnePlus 9 Pro, which is less fragile when it falls than the Mi 11 Ultra ceramics.
7.Price and Availability in 2021
In Russia and CIS countries, the prices for flagships in 2021 differ significantly, and at the time of release (spring-summer 2021), the cost was as follows:
- OnePlus 9 Pro (8/128 GB): ~75 000 ₽.
- Xiaomi Mi 11 Ultra (12/256 GB): ~90 000 ₽.
By the end of the year, however, Xiaomi had begun aggressive discounts, and the Mi 11 Ultra could be found for 65,000-70,000. ₽, And that made it a better proposition. F3 (25,000 ₽) Bypassed OnePlus Nord 2 (from 35 000) ₽) Price/performance, but lost out on screen and cameras.
Where to buy:
- 🛒 Official stores: mi.com (guarantee 2 years), oneplusstore.ru (guarantee 1 year).
- 🌍 Marketplaces: Wildberries, Ozon (risk of "gray" imports).
- 🇨🇳 Aliexpress: only if you are willing to wait 3-4 weeks and risk customs.
⚠️ Warning: When buying Xiaomi on Aliexpress, check the firmware region! MIUI Google Services does not support Google Services and has Russian language restrictions.