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ROG Phone II ZS660KL 1024GB vs vivo X21 UD (2018) 128GB: Full Comparison!

Created date: 2019-07-23 04:55:02, Updated date: 2021-10-20 17:45:24

ROG Phone II ZS660KL 1024GBvivo X21 UD (2018) 128GB
ROG Phone II ZS660KL 1024GBvivo X21 UD (2018) 128GB

Are you having trouble comparing the differences in features and performance of the "ROG Phone II ZS660KL 1024GB" and "vivo X21 UD (2018) 128GB", or unsure about their differences in ease-of-use, and wondering which to buy? We did a deep-dive comparison of the features, specs, and capabilities of these two smartphone, and provided our rating of which one was a better buy.

ROG Phone II ZS660KL 1024GBvivo X21 UD (2018) 128GB
ROG Phone II ZS660KL 1024GB

vivo X21 UD (2018) 128GB

General rating:
Portabilityrating-image2.8
55/100
rating-image3.2
64/100
Weightrating-image2.2
44/100
rating-image3.4
67/100
Size of screenrating-image4.5
90/100
rating-image4.5
90/100
Screen clarityrating-image4.1
82/100
rating-image4.2
84/100
Battery durationrating-image4.3
86/100
rating-image3.4
68/100
Processing capabilityrating-image4.9
98/100
rating-image4.5
90/100
Memory capacityrating-image5.0
99/100
rating-image4.5
90/100
Storage capacityrating-image5.0
99/100
rating-image4.5
90/100
Rear camera functionrating-image4.9
97/100
rating-image3.0
59/100
Front camera functionrating-image4.3
86/100
rating-image3.5
70/100

Compare Performance and Usability

Size comparison of "ROG Phone II ZS660KL 1024GB" and "vivo X21 UD (2018) 128GB". Which one would you choose?

Your device's size has a huge influence on how easy it is to hold or to operate with one hand. The smaller your device's width, the easier it will be to hold, but you'll also need to take device thickness into account. And when the length and width are both smaller, you'll find that it's much easier for you to operate it one-handed, since your fingers will find it much easier to reach where you want them to. On the other hand, longer lengths and wider widths might lead to devices that are hard to carry in your pocket, bulky even when you keep them in your bag, and all around less portable.

The "ROG Phone II ZS660KL 1024GB" is 77.6mm wide, 171.0mm tall, and 9.5mm thick. The "vivo X21 UD (2018) 128GB" is 74.8mm tall, 154.5mm wide, and 7.4mm thick.

Comparing the width and thickness of the main unit, the "vivo X21 UD (2018) 128GB" is smaller and more compact compared to the "ROG Phone II ZS660KL 1024GB". Therefore, it is easier to grip and hold the "vivo X21 UD (2018) 128GB" than the "ROG Phone II ZS660KL 1024GB". For this reason, the "vivo X21 UD (2018) 128GB" is recommended.

Comparing the width and height of the main unit, the "vivo X21 UD (2018) 128GB" is smaller and more compact than the "ROG Phone II ZS660KL 1024GB". As a result, the "vivo X21 UD (2018) 128GB" is easier to operate with one hand and it is more portable without getting in your way than the "ROG Phone II ZS660KL 1024GB". Therefore, the "vivo X21 UD (2018) 128GB" is recommended.

Comparing the overall size of the main unit, the "vivo X21 UD (2018) 128GB" is smaller than the "ROG Phone II ZS660KL 1024GB". As a result, it is easier to use the "vivo X21 UD (2018) 128GB" with one hand compared to the "ROG Phone II ZS660KL 1024GB", and its size makes it more comfortable to carry around. For this reason, the "vivo X21 UD (2018) 128GB" is recommended.

ScoreDimensions (width x height x thickness)
ROG Phone II ZS660KL 1024GB55/10077.6mm x 171.0mm x 9.5mm
vivo X21 UD (2018) 128GB64/10074.8mm x 154.5mm x 7.4mm

Which one is easier to hold, "ROG Phone II ZS660KL 1024GB" or "vivo X21 UD (2018) 128GB"? Compare weight

The device weight will effect how quickly you tire from holding it, and how much stress is put on your wrist. The lighter it is, the longer you can hold it without feeling tired. Also, less stress on your wrist will make using it easier and more pleasant. Unless the weight is right for you, it might put too much strain on your body and make using it more stressful.

The "ROG Phone II ZS660KL 1024GB" weighs 240.0g. The "vivo X21 UD (2018) 128GB" clocks in at 156.2g. If you compare the weight of the two, the "vivo X21 UD (2018) 128GB" is a considerably lighter smartphone than the "ROG Phone II ZS660KL 1024GB", with a difference of about 83.8g. Because of this, the "vivo X21 UD (2018) 128GB" puts less of a burden on the fingers and wrists than the "ROG Phone II ZS660KL 1024GB". If you want a smartphone that won't tire your hands out even when using it for a long time, we recommend that you buy the "vivo X21 UD (2018) 128GB" rather than the "ROG Phone II ZS660KL 1024GB".

ScoreWeight
ROG Phone II ZS660KL 1024GB44/100240.0g
vivo X21 UD (2018) 128GB67/100156.2g

Which is better in terms of display, "ROG Phone II ZS660KL 1024GB" or "vivo X21 UD (2018) 128GB"?

Screen size influences how well you can control your device, as well as how clear the display is. With a large screen, the text and buttons in apps will display large enough so you'll be less likely to accidentally tap the button next to the one you were aiming for. Plus, you'll be able to enjoy more high-impact visuals for games and movies.

The screen size on the "ROG Phone II ZS660KL 1024GB" is 6.59inch, and 6.28inch on the "vivo X21 UD (2018) 128GB". The screens of the "ROG Phone II ZS660KL 1024GB" and "vivo X21 UD (2018) 128GB" are roughly the same size, and so the ease of pressing app buttons are the same on both devices. Because of this, it is better to compare them based on other aspects of performance and function.

ScoreDisplay size
ROG Phone II ZS660KL 1024GB90/1006.59inch
vivo X21 UD (2018) 128GB90/1006.28inch

Which one has a better display, "ROG Phone II ZS660KL 1024GB" or "vivo X21 UD (2018) 128GB"?

Pixel density influences how nice your device's screen looks, with high pixel densities making screens look more beautiful, and letting you get more out of your games and movies. Plus, the nicer you screen looks, the less strain you'll be putting on your eyes, so you'll tend to be able to use your device for longer before your eyes get tired.

The screen on the "ROG Phone II ZS660KL 1024GB" has a 1080 x 2340 resolution and a pixel density of 391ppi. The "vivo X21 UD (2018) 128GB", on the other hand, has a screen resolution of 1080 x 2280 and a pixel density of 401ppi. There is not much of a difference in the pixel resolutions of the "ROG Phone II ZS660KL 1024GB" and "vivo X21 UD (2018) 128GB", so they are about the same in terms of clarity of image and gentleness on the eyes. For this reason it is better to compare them based on other aspects of performance and function.

ScorePixel density
ROG Phone II ZS660KL 1024GB82/100391ppi
vivo X21 UD (2018) 128GB84/100401ppi

How is the battery duration of "ROG Phone II ZS660KL 1024GB" different from that of "vivo X21 UD (2018) 128GB" ? See the differences

Battery performance has a big effect on the battery life of your device. However, a high battery capacity doesn't necessarily mean a long battery life. Rather, the rate of power consumption needs to be taken into consideration as well. The larger the screen and the higher the CPU performance, the higher the rate of power consumption on your battery.

The "ROG Phone II ZS660KL 1024GB" has a battery capacity of 6000.0mAh, while the "vivo X21 UD (2018) 128GB" has a 3200.0mAh battery. With regards to battery performance, the "ROG Phone II ZS660KL 1024GB" has a substantially larger battery capacity than the "vivo X21 UD (2018) 128GB", with a difference of 2800mAh. The "ROG Phone II ZS660KL 1024GB" can be used without charging for a longer time than the "vivo X21 UD (2018) 128GB", so it can be used when out and about. If you want a smartphone with a longer-lasting battery, we recommend that you buy the "ROG Phone II ZS660KL 1024GB" rather than the "vivo X21 UD (2018) 128GB".

ScoreBattery capacity
ROG Phone II ZS660KL 1024GB86/1006000.0mAh
vivo X21 UD (2018) 128GB68/1003200.0mAh

Which is better in terms of CPU function, "ROG Phone II ZS660KL 1024GB" or "vivo X21 UD (2018) 128GB"?

Your CPU's speed will influence the processing power of the applications you run, and together with the number of cores in the CPU, as well as its clock frequency, will determine the processing power available for apps. The higher these performance factors, the smoother your games and apps will run. Conversely, if these factors are too low, your apps and games will be sluggish and struggle to run.

The "ROG Phone II ZS660KL 1024GB" is equipped with a Qualcomm SM8150 Snapdragon 855+ processor, and its performance speed is 2.96GHz+2.42GHz+1.78GHz×8(8.0-cores). The "vivo X21 UD (2018) 128GB" uses an Qualcomm SDM660 Snapdragon 660 CPU that performs at a speed of 2.2GHz+1.8GHz×8(8.0-cores). Comparing their CPU performance, the "ROG Phone II ZS660KL 1024GB" has higher specs than the "vivo X21 UD (2018) 128GB". For this reason, applications run better on the "ROG Phone II ZS660KL 1024GB" compared to the "vivo X21 UD (2018) 128GB", and games run very smoothly. Therefore, the "ROG Phone II ZS660KL 1024GB" is recommended.

ScoreCPU specs
ROG Phone II ZS660KL 1024GB98/1002.96GHz+2.42GHz+1.78GHz×8(8.0-cores)
vivo X21 UD (2018) 128GB90/1002.2GHz+1.8GHz×8(8.0-cores)

How is "ROG Phone II ZS660KL 1024GB" different from "vivo X21 UD (2018) 128GB" in terms of memory capacity?

Your device's multimedia performance and app stability are both influenced by the amount of memory it has available. The more memory, the more apps you can use simultaneously, while keeping everything stable and smooth. Plus, there'll be less chance of animations lagging or apps crashing. You also need to keep in mind that some games won't run at all if there's not enough memory available.

The "ROG Phone II ZS660KL 1024GB" has 12.0GB of memory. The "vivo X21 UD (2018) 128GB", on the other hand, has 6.0GB. Comparing the memory performance, the "ROG Phone II ZS660KL 1024GB" has a larger memory capacity than the "vivo X21 UD (2018) 128GB", with a difference of approximately 6GB. For this reason, multitasking is smoother on the "ROG Phone II ZS660KL 1024GB" than the "vivo X21 UD (2018) 128GB", and applications are less likely to crash. Also, it is more enjoyable to play 3D games and VR on the "ROG Phone II ZS660KL 1024GB". For this reason, the "ROG Phone II ZS660KL 1024GB" is recommended.

ScoreRAM size
ROG Phone II ZS660KL 1024GB99/10012.0GB
vivo X21 UD (2018) 128GB90/1006.0GB

Which has a better storage capacity, "ROG Phone II ZS660KL 1024GB" or "vivo X21 UD (2018) 128GB"?

Storage capacity determines the amount of data you'll be able to save on your device. The more storage you have, the more photos you can take and the more apps you can install. Plus, if your smartphone is compatible with SD cards, then you can increase the amount of available storage. However, SD cards have a slower writespeed, making them less desirable in terms of performance, and users should be aware that it won't be possible to transfer all kinds of data to the card.

The "ROG Phone II ZS660KL 1024GB" has 1024.0GB of storage, while the "vivo X21 UD (2018) 128GB" has 128.0GB. Comparing the ROM and storage capacity, the "ROG Phone II ZS660KL 1024GB" has a larger storage capacity compared to the "vivo X21 UD (2018) 128GB", with a difference of approximately 896GB. Consequently, the "ROG Phone II ZS660KL 1024GB" can take more photos and videos than the "vivo X21 UD (2018) 128GB" and it is possible to install more applications on it. For this reason, the "ROG Phone II ZS660KL 1024GB" is recommended.

ScoreStorage size
ROG Phone II ZS660KL 1024GB99/1001024.0GB
vivo X21 UD (2018) 128GB90/100128.0GB

Compare the rear cameras of "ROG Phone II ZS660KL 1024GB" and "vivo X21 UD (2018) 128GB". Which one has better picture quality?

One factor in how well your rear camera (the camera on the back of your device) performs is its megapixel count. With a higher megapixel count, you'll be able to take photos with sharper detail, photos that stay clear and sharp even when printed.

The main camera on the "ROG Phone II ZS660KL 1024GB" has 48.0MP. The "vivo X21 UD (2018) 128GB" has 12.0MP. The rear-facing camera of the "ROG Phone II ZS660KL 1024GB" also has a higher pixel count than the "vivo X21 UD (2018) 128GB", with a difference of about 36MP. The "ROG Phone II ZS660KL 1024GB" is more capable than the "vivo X21 UD (2018) 128GB" of taking high-definition photos and videos, and produces better results when printing out the photos you have taken. If you want a smartphone that is designed for video and photography, we recommend buying the "ROG Phone II ZS660KL 1024GB" rather than the "vivo X21 UD (2018) 128GB".

ScoreRear-camera resolution
ROG Phone II ZS660KL 1024GB97/10048.0MP
vivo X21 UD (2018) 128GB59/10012.0MP

Which has a front camera with better picture quality, "ROG Phone II ZS660KL 1024GB" or "vivo X21 UD (2018) 128GB"?

One indication of how well your forward facing camera (the camera on the same side as your device's screen) performs is how many megapixels it has. More megapixels means you'll be able to take photos with sharper detail, that still look amazing printed out.

The forward-facing camera on the "ROG Phone II ZS660KL 1024GB" has a resolution of 24.0MP. The "vivo X21 UD (2018) 128GB"'s has 12.0MP. The front-facing camera of the "ROG Phone II ZS660KL 1024GB" has a significantly higher number of pixels than the "vivo X21 UD (2018) 128GB", with a difference of about 12MP. Therefore, the "ROG Phone II ZS660KL 1024GB" is more suitable for taking photos and videos than the "vivo X21 UD (2018) 128GB". If you want to take and print high-quality selfies, we recommend buying the "ROG Phone II ZS660KL 1024GB" rather than the "vivo X21 UD (2018) 128GB".

ScoreFront-camera resolution
ROG Phone II ZS660KL 1024GB86/10024.0MP
vivo X21 UD (2018) 128GB70/10012.0MP

Compare Performance Specs

ROG Phone II ZS660KL 1024GBvivo X21 UD (2018) 128GB
ImageROG Phone II ZS660KL 1024GBvivo X21 UD (2018) 128GB
MakerAsusvivo
Release date2019-092018-03
ColorMatte Black/Glossy BlackBlack/Ruby Red
OSAndroidAndroid
Dimensions (width x height x thickness)77.6mm x 171.0mm x 9.5mm74.8mm x 154.5mm x 7.4mm
Weight240.0g156.2g
Display size6.59inch6.28inch
Display typeAMOLEDSuper AMOLED
Screen resolution (width x height)1080 x 23401080 x 2280
Pixel density391ppi401ppi
Battery capacity6000.0mAh3200.0mAh
ChipsetQualcomm SM8150 Snapdragon 855+Qualcomm SDM660 Snapdragon 660
CPU specs2.96GHz+2.42GHz+1.78GHz×8(8.0-cores)2.2GHz+1.8GHz×8(8.0-cores)
RAM size12.0GB6.0GB
Storage size1024.0GB128.0GB
Rear-camera resolution48.0MP12.0MP
Front-camera resolution24.0MP12.0MP

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