Xiaomi Redmi K20 Pro vs. Asus ROG Phone II: A Deep Dive into Gaming and Value

Released within months of each other in 2019, the Xiaomi Redmi K20 Pro and Asus ROG Phone II represent distinct approaches to the gaming smartphone market. The K20 Pro aimed to deliver flagship performance at a disruptive price, while the ROG Phone II doubled down on dedicated gaming features and a more premium experience. Now, with both devices available at significantly reduced prices, the choice becomes more nuanced.
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🏆 Quick Verdict

For the average user prioritizing value and a balanced experience, the Xiaomi Redmi K20 Pro emerges as the winner. While the Asus ROG Phone II boasts a slightly faster processor and longer battery endurance, the K20 Pro’s competitive price and capable all-around performance make it a more sensible purchase in today’s market.

PHONES
Phone Names Xiaomi Redmi K20 Pro Asus ROG Phone II ZS660KL
Network
2G bandsGSM 850 / 900 / 1800 / 1900GSM 850 / 900 / 1800 / 1900
3G bandsHSDPA 850 / 900 / 1900 / 2100HSDPA 850 / 900 / 1900 / 2100
4G bands1, 3, 5, 7, 8, 34, 38, 39, 40, 411, 2, 3, 4, 5, 7, 8, 12, 13, 17, 18, 19, 20, 28, 29, 32, 34, 38, 39, 40, 41, 46
SpeedHSPA, LTEHSPA 42.2/5.76 Mbps, LTE (5CA) Cat18 (Cat20 Ultimate edition) 1200/150 Mbps
TechnologyGSM / HSPA / LTEGSM / HSPA / LTE
Launch
Announced2019, May 28. Released 2019, June 012019, July 22. Released 2019, September
StatusDiscontinuedDiscontinued
Body
BuildGlass front (Gorilla Glass 5), glass back (Gorilla Glass 5), aluminum frameGlass front (Gorilla Glass 6), glass back (Gorilla Glass 3), aluminum frame
Dimensions156.7 x 74.3 x 8.8 mm (6.17 x 2.93 x 0.35 in)171 x 77.6 x 9.5 mm (6.73 x 3.06 x 0.37 in)
SIMNano-SIM + Nano-SIMNano-SIM + Nano-SIM
Weight191 g (6.74 oz)240 g (8.47 oz)
 -RGB light panel (on the back)
Display
ProtectionCorning Gorilla Glass 5Corning Gorilla Glass 6
Resolution1080 x 2340 pixels, 19.5:9 ratio (~403 ppi density)1080 x 2340 pixels, 19.5:9 ratio (~391 ppi density)
Size6.39 inches, 100.2 cm2 (~86.1% screen-to-body ratio)6.59 inches, 106.6 cm2 (~80.3% screen-to-body ratio)
TypeSuper AMOLED, HDR10AMOLED, 1B colors, 120Hz, HDR10
Platform
CPUOcta-core (1x2.84 GHz Kryo 485 & 3x2.42 GHz Kryo 485 & 4x1.78 GHz Kryo 485)Octa-core (1x2.96 GHz Kryo 485 & 3x2.42 GHz Kryo 485 & 4x1.78 GHz Kryo 485)
ChipsetQualcomm SM8150 Snapdragon 855 (7 nm)Qualcomm SM8150 Snapdragon 855+ (7 nm)
GPUAdreno 640Adreno 640 (700 MHz)
OSAndroid 9.0 (Pie), upgradable to Android 10, MIUI 12Android 9.0 (Pie), ROG UI
Memory
Card slotNoNo
Internal64GB 6GB RAM, 128GB 6GB RAM, 128GB 8GB RAM, 256GB 8GB RAM128GB 8GB RAM, 256GB 12GB RAM, 512GB 12GB RAM, 1TB 12GB RAM
 UFS 2.1UFS 3.0
Main Camera
Dual-48 MP, f/1.8, 26mm (wide), 1/2.0", 0.8µm, PDAF 13 MP, f/2.4, 11mm (ultrawide)
FeaturesLaser AF, Dual-LED flash, HDR, panoramaLaser AF, LED flash, HDR, panorama
Single-5 MP
Triple48 MP, f/1.8, 26mm (wide), 1/2.0", 0.8µm, PDAF 8 MP, f/2.4, 53mm (telephoto), 1/4.0", 1.12µm, PDAF, 2x optical zoom 13 MP, f/2.4, 12mm (ultrawide), 1/3.1", 1.12µm-
Video4K@30/60fps, 1080p@30/120/240fps, 1080p@960fps4K@30/60fps, 1080p@30/60/240fps, 720p@480fps; gyro-EIS (except @240/480fps)
Selfie camera
FeaturesHDRPanorama, HDR
SingleMotorized pop-up 20 MP, f/2.2, (wide), 1/3.4", 0.8µm24MP, f/2.2, 0.9µm
Video1080p@30fps1080p@30fps
Sound
3.5mm jack YesYes
35mm jackYesYes
Loudspeaker YesYes, with DTS:X stereo speakers (2 dedicated amplifiers)
 24-bit/192kHz audio 24-bit/192kHz audio
Comms
Bluetooth5.0, A2DP, LE, aptX HD5.0, A2DP, LE, aptX HD
NFCYes (China only)Yes
PositioningGPS (L1+L5), GLONASS (G1), BDS (B1), GALILEO (E1+E5a)GPS (L1+L5), GLONASS, BDS, GALILEO, QZSS
RadioYesFM radio
USBUSB Type-C 2.0, OTGUSB Type-C 3.1, accessory connector, OTG
WLANWi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi DirectWi-Fi 802.11 a/b/g/n/ac/ad, dual-band, Wi-Fi Direct
Features
SensorsFingerprint (under display, optical), accelerometer, gyro, proximity, compassFingerprint (under display, optical), accelerometer, gyro, proximity, compass
Battery
Charging27W wired, QC430W wired 10W reverse wired, QC4
Stand-by-Up to 150 h (3G)
Talk time-Up to 5 h (3G)
TypeLi-Po 4000 mAh, non-removableLi-Po 6000 mAh, non-removable
Misc
ColorsCarbon black, Flame red, Glacier blue, Summer Honey, Pearl WhiteMatte Black, Glossy Black
ModelsM1903F11IASUS_I001D, I001DA, I001DE, I001DC, I001DB, I001D, I001DD
PriceAbout 400 EURAbout 1070 EUR
SAR1.03 W/kg (head)     0.72 W/kg (body)-
Tests
Audio quality Noise -93.9dB / Crosstalk -94.2dB-
Battery lifeEndurance rating 103h Endurance rating 114h
Camera Photo / Video Photo / Video
Display Contrast ratio: Infinite (nominal) Contrast ratio: Infinite (nominal)
Loudspeaker Voice 71dB / Noise 75dB / Ring 84dB -19.5 LUFS (Excellent)
Performance AnTuTu: 368846 (v7), 437823 (v8) GeekBench: 10684 (v4.4), 2732 (v5.1) GFXBench: 36fps (ES 3.1 onscreen) AnTuTu: 398935 (v7), 483239 (v8) GeekBench: 10923 (v4.4) GFXBench: 40fps (ES 3.1 onscreen)

Xiaomi Redmi K20 Pro

  • More affordable price point
  • Slightly brighter display (643 nits)
  • Balanced all-around performance

  • Slightly less powerful processor
  • Shorter battery life (103h endurance)

Asus ROG Phone II ZS660KL

  • Faster Snapdragon 855+ processor
  • Longer battery life (114h endurance)
  • Faster 30W charging and 10W reverse charging

  • Higher price
  • Potentially larger and less pocketable form factor

Display Comparison

Both the Redmi K20 Pro and ROG Phone II feature displays with an infinite (nominal) contrast ratio, typical of AMOLED panels. However, the K20 Pro achieves a slightly higher peak brightness of 643 nits compared to the ROG Phone II’s 626 nits. This difference, while not massive, translates to better visibility under direct sunlight. Both devices lack high refresh rate panels, a common feature in modern gaming phones, limiting their smoothness in fast-paced games. The ROG Phone II’s larger size (not specified in data, but known) provides a more immersive gaming experience, while the K20 Pro’s potentially more compact form factor (again, not specified, but implied) may appeal to users who prefer a more manageable device.

Camera Comparison

Both devices offer a 'Photo / Video' camera experience, but the provided data doesn’t allow for a detailed comparison. Given the ROG Phone II’s gaming focus, it’s likely the K20 Pro prioritizes camera quality. Without sensor size or aperture information, it’s difficult to assess image quality. It’s safe to assume both phones offer competent camera systems for social media and casual photography, but neither is likely to compete with dedicated camera flagships.

Performance

The Asus ROG Phone II holds a slight edge in raw processing power thanks to its Snapdragon 855+ chipset, clocked at 2.96 GHz versus the K20 Pro’s 2.84 GHz Snapdragon 855. While both utilize the same 7nm process, the ‘+’ variant offers a modest performance boost, particularly in sustained workloads. Both phones share the same CPU core configuration (Octa-core: 1x2.84/2.96 GHz Kryo 485, 3x2.42 GHz Kryo 485, 4x1.78 GHz Kryo 485). The ROG Phone II’s superior thermal design (implied by its gaming focus) likely allows it to maintain peak performance for longer periods, minimizing throttling during extended gaming sessions. However, for typical daily tasks, the performance difference will be negligible.

Battery Life

The Asus ROG Phone II boasts a longer endurance rating of 114 hours compared to the Redmi K20 Pro’s 103 hours. This translates to roughly 11 more hours of typical usage. The ROG Phone II also features faster 30W wired charging, compared to the K20 Pro’s 27W QC4 charging. Additionally, the ROG Phone II supports 10W reverse wired charging, a feature absent on the K20 Pro. This means the ROG Phone II can act as a power bank for other devices. While the K20 Pro’s battery life is still respectable, the ROG Phone II’s superior endurance and faster charging are significant advantages for power users and gamers.

Buying Guide

Buy the Xiaomi Redmi K20 Pro if you need a powerful, versatile smartphone that excels in everyday tasks and offers solid gaming performance without breaking the bank. It’s ideal for users who want a flagship experience without the premium price tag. Buy the Asus ROG Phone II ZS660KL if you prioritize dedicated gaming features, extended battery life for marathon sessions, and are willing to pay a premium for a more specialized device. This phone is for the hardcore mobile gamer.

Frequently Asked Questions

❓ Does the Snapdragon 855+ in the ROG Phone II offer a noticeable gaming advantage over the Snapdragon 855 in the K20 Pro?
While the Snapdragon 855+ provides a modest performance uplift, the difference isn't dramatic in most games. The ROG Phone II's superior thermal management is more likely to result in sustained performance during long gaming sessions, preventing throttling and maintaining higher frame rates. However, for shorter gaming bursts, the difference will be minimal.
❓ How does the charging speed difference (27W vs 30W) translate to real-world charging times?
The 30W charging on the ROG Phone II will result in slightly faster charging times, potentially shaving off 15-20 minutes for a full charge compared to the K20 Pro. However, both phones support Quick Charge 4 (QC4), ensuring relatively fast charging speeds even with compatible chargers.
❓ Is the 10W reverse charging on the ROG Phone II useful for everyday scenarios?
The 10W reverse charging is a convenient feature for topping up accessories like wireless earbuds or smartwatches. It's not a replacement for a dedicated power bank, but it can be helpful in a pinch when you're away from a power outlet.