When buying a smartphone, we only look at the storage capacity (64GB or 128GB) which is not an accurate way to determine the storage performance.
The internal storage of a smartphone is responsible for a lot of tasks e.g. turning on a smartphone requires reading the operating system from the internal storage and loading it on to the Ram. This task time to complete depends on the internal storage speed (more specifically random reads). The higher the internal storage speed, the faster a smartphone will start.
Another example is when you switch between demanding applications like PUBG mobile and playing a video stored in internal storage. This is where most smartphones lag and stutter because the processor can not read and write on to the internal storage fast enough. In this case, the internal storage is the bottleneck.
The above-mentioned tasks are demanding. But even the simpler tasks like opening a PowerPoint presentation, compiling a Microsoft Word document and switching between normal applications require good random reads and writes of internal storage to keep the smartphone smooth.
Flagship smartphones these days have UFS 3.0 storage which is really fast but most budget or even some mid-range smartphones carry eMMC 5.1 storage which is a lot slower than any UFS storage.
In 2019 and 2020, even budget smartphones have at least 64 GB of internal storage which is plenty for 80% of the people.
The storage capacity does help as you will have more storage to store files. We all know what happens when the storage is 90% or more is filled, the smartphone stutters.
One more benefit of having higher storage is they often perform better than their lower memory versions. This is due to the property of NAND Flash performing better when it has more memory blocks to write at a time.
Due to the abundance of storage capacity available in every smartphone, it seems useless now more than ever to just look at the capacity of storage instead of the performance or speeds.
According to linustechtips, 64GB capacity seems enough for most people.
In 2020, storage performance or speed should be given more importance than storage capacity.
But to understand storage performance, first, we need to know the types of internal storage in smartphones these days.
There are are two major types of storage eMMC (embedded Multi Media Card) and UFS (Universal Flash Storage).
The table above gives a rough idea of the speeds of different smartphone storage.
All of the budget smartphones have eMMC 5.1 storage, most mid-range smartphones also have eMMC 5.1 storage and some mid-range smartphones have UFS 2.0. Flagship or top of the line smartphones has either UFS 2.0, UFS 2.1 or UFS 3.0.
Only a handful of smartphones in 2019 had UFS 3.0 and it was OnePlus 7 Pro and Samsung Note 10. It is important to point out that OnePlus 7 Pro transfer rates are way below than the ones given in the above table. The Samsung Note 10 which also has UFS 3.0 had the best transfer rates and performance in 2019.
Now that we know there are different types of storage in smartphones, we have to analyze the factors that affect the performance of smartphone storage.
Smartphone Storage Performance:
Suppose you are buying a smartphone and you think that UFS 2.1 is definitely better than UFS 2.0. This would not be true.
Let me first explain that smartphone storage transfer rates or speeds are not an indicator of the smartphone day to day performance.
The thing is that transfer rates that are written are mostly sequential reads and write. Sequential read means reading from memory that is next to each other which rarely happens in a day to day usage scenario.
The most important benchmarks of storage (any type of storage SSD, HDD, SD card, internal storage) are random reads/write and IOPS (Input-output operations per second).
When you switch between applications continuously on a smartphone, random reads and write operations are being performed on the internal storage. You are dealing with random reads and writes more often than sequential reads and writes.
This is why you should care about random reads and writes.
The IOPS (Input-Output per second) are associated with sequential reads/writes as well as random reads/writes. Basically the higher the number IOPS of storage random reads and writes, the better the storage performance will be. As the name suggests, storage will be able to perform more input-output operations per second.
You can think of IOPS as all the commands or operations that are executed when moving a memory block from one place to another. If the memory blocks are next to each other, there would be fewer commands (fewer IOPS are required) to execute. If the memory blocks are randomly placed, it would take more commands (more IOPS are required) and therefore more time to move that memory block.
Now assume, you are moving a lot of small memory blocks. Would it take more time and commands to move a data consists of large chunks or small chunks?
It would take more commands and time to move data that contains small chunks. This is why 4K (4 Kilo-Bytes) memory blocks are included in every storage benchmarks.
Now assume this small chunk of data is also random. This is 4K random which involves a lot like a lot of operations or commands. This is the reason why random 4K blocks are used to get IOPS of storage.
What have we learned so far.
- Look at the type of storage
- Look at the random reads/writes
- Look at the IOPS of random reads/writes
Comparison of Smartphone Storages
Most of the Flagship smartphones in 2018 and 2019 are using UFS 2.1. It does not mean that all of the smartphones have the same storage performance. I am going to compare all the Flagship smartphones storage of 2018.
|Phone||Storage type||Sequential Read||Sequential Write||Random Read||Random Write|
|Samsung S9||UFS 2.1||683 MB/s||109 MB/s||6 MB/s||1 MB/s|
|Samsung Note 9||UFS 2.1||691 MB/s||119 MB/s||10 MB/s||1 MB/s|
|Pixel 3||UFS 2.1||588 MB/s||205 MB/s||24 MB/s||33 MB/s|
|Pixel 3XL||NVMe||600 MB/s||233 MB/s||25 MB/s||33 MB/s|
|iPhone X||UFS 2.1||1179 MB/s||178 MB/s||MB/s||MB/s|
|OnePlus 6||UFS 2.1||665 MB/s||147 MB/s||20 MB/s||7 MB/s|
|OnePlus 6T||UFS 2.1||667 MB/s||147 MB/s||20 MB/s||6 MB/s|
|LG G7||UFS 2.1||662 MB/s||114 MB/s||16 MB/s||6 MB/s|
|LG V40||UFS 2.1||645 MB/s||112 MB/s||16 MB/s||5 MB/s|
|Razer Phone 2||UFS 2.1||666 MB/s||149 MB/s||23 MB/s||7 MB/s|
The table proves that not all UFS 2.1 storage the same. This is why we have to look at the storage performance of each smartphone separately. Just looking at the storage type (eMMC 5.1, UFS 2.0 or 2.1) do not tell us anything.
Now look closely at the random reads and writes of the smartphones given in the table. Random reads and writes are higher in good quality storage.
Only the Google Pixel 3 and 3XL were able to provide really good random read and write speeds. Other than that, OnePlus 6 and 6T are really impressive considering their price.
The one that I was concerned about was Samsung Note 9 which costs 1000$ and can not even beat the other smartphones that cost less.
The iPhone X NVMe storage is impressive. It definitely beats every other smartphone in sequential speeds. Moreover, these transfer rates further increase as we move to 256GB iPhone X.
The write speeds are four times better on the 256 GB version. Just look at the screenshots below from Notebookcheck.
Do not be surprised by this. It is pretty common for a higher amount of storage performing better than the lower amount of storage. This happens all the time in USB Flash drives and SSD.
Smartphone Storage is Really important:
Smartphone storage is far more important than most people realize. This applies especially to average consumers who just want to use their smartphones for normal usage.
Smartphone storage is just like a hard disk in the computer which is the slowest part. Ram (random access memory) which has about 8-10 GBPS bandwidth in a smartphone and the smartphone internal storage is about 600MBPS bandwidth. Although the Flash storage in a smartphone is way faster than any hard disk, still it is the slowest part of a smartphone.
Did you ever wonder why the Apple iPhones and Google Pixel are smoother and more fluid than other smartphones, especially iPhones? This is due to the better optimization of the software but also due to the higher number of IOPS in random reads and writes.
Some people reading this might be like why is the Google Pixel smoother than other smartphones? Actually it is, I realized this by using it myself. Also, Google Pixel 3 even beats the Samsung Note 9 in the PCWork benchmark.
For normal or average consumers who use their smartphones just for business or fun. The PCMark for Android Work and PCMark for Android Work 2.0 benchmarks are best to determine if a smartphone would have good performance for average people. This benchmark tests the performance of web browsing, video playback, compiling a document of text and pictures, Photo Editing, and Video Editing.
I have shared a link below that has almost all the flagships from 2018 and their PCMark for Android Work is given. Look at the link and you will find Google Pixel there.
Recommended Sources to Check Storage Performance
Whenever I have to buy a smartphone, I would search benchmarks for each of its components like CPU, Storage, and Wifi, etc. There are some websites that are really helpful if you need to check the performance of the storage of a specific smartphone.
I am just going to list these sources in the list below:
That’s all because most websites do not even take storage into consideration when reviewing a smartphone.
Hope you found this article helpful.
If you missed the first part where I discussed the performance factors of Smartphone Processor. Check it out.