Smartphones generally do not contain traditional hard disk drives (HDDs) like you would find in a laptop or desktop computer. Instead, most modern smartphones use flash-based solid state drives (SSDs) for internal storage.
Why don’t smartphones use HDDs?
There are a few key reasons why HDDs are not well-suited for use in smartphones:
- Size – HDDs have moving mechanical parts that take up a lot of space. Smartphones are designed to be slim and compact, so there isn’t room to fit a bulky HDD inside.
- Durability – The mechanical nature of HDDs makes them more prone to damage from drops or bumps. Smartphones experience a lot of wear and tear from frequent mobility, so a fragile HDD would be vulnerable.
- Power consumption – HDDs require more power to run than SSDs, which would drain smartphone batteries much faster.
- Performance – HDDs have slower read/write speeds compared to SSDs, which would lead to lag and delays in phone usage.
- Noise – HDDs generate audible noise from their spinning platters, which would be undesirable in a smartphone.
SSDs solve all of these issues by being based on flash memory chips rather than mechanical parts. This makes them compact, durable, energy efficient, high-performance, and silent. For these reasons, virtually every smartphone uses NAND flash SSD storage rather than HDDs.
What type of SSD do smartphones use?
While they all use SSDs, not every smartphone SSD is the same. There are a few common types of SSD storage found in modern phones:
- UFS (Universal Flash Storage) – UFS is a high-speed flash storage standard designed specifically for mobile devices like smartphones. UFS SSDs offer excellent read/write speeds and low power consumption. They are the premier choice for flagship phones from Samsung, Google, Xiaomi, and other major brands.
- eMMC (Embedded Multi-Media Controller) – eMMC SSDs integrate the flash memory and controller into a single package. They are a cost-effective, reliable option well-suited for budget and mid-range smartphones. eMMC drives are a very common choice for lower-end Android phones.
- NVMe (Non-Volatile Memory Express) – NVMe SSDs use the PCIe interface and provide the fastest speeds out of the main SSD types. They are less commonly used in smartphones due to their higher cost, but some premium phones like the Samsung Galaxy S22 Ultra utilize NVMe SSDs.
Within these categories, there are additional variables like whether the NAND flash chips are built on the older 2D planar tech or the newer 3D V-NAND architecture. But UFS, eMMC, and NVMe cover the majority of SSD solutions being used in modern smartphones.
Internal storage capacity
In addition to the SSD type, the internal storage capacity also varies significantly among different smartphone models. Entry-level phones may have as little as 8GB or 16GB of storage. Mid-range devices generally offer 64GB or 128GB. Flagship phones aimed at power users often push up to 256GB or even 512GB.
More internal storage allows you to install more apps, download more files and media, and capture more photos/videos without needing to juggle or delete content. However, most manufacturers offer multiple storage tier options at different price points. A budget buyer who stores minimal data on their phone could get by with a 16GB or 32GB SSD model, while a photography buff would likely want a 256GB or 512GB version.
Using microSD cards for expandable storage
Some smartphones support expandable storage through microSD cards. This allows you to effectively increase the storage capacity by inserting a removable memory card. Cards up to 1TB are available, enabling huge storage expansion potential. There are a few benefits to microSD card slots:
- Cheap capacity upgrades – You can add 128GB+ of extra space for less than $20-30 with an SD card.
- Flexibility – Easily insert or swap cards to change storage allotments.
- Media portability – Remove the card to transfer photos/videos between devices.
However, microSD storage comes with some downsides as well:
- Slower speeds than internal SSDs, which can impact performance.
- Less durable and more prone to corruption than SSDs.
- Not all apps or files can be stored on removable storage.
Due to these limitations, smartphone brands have been moving away from microSD slots in recent years. But you can still find them in many mid-range Android devices from companies like Samsung, Motorola, and Google.
How smartphone SSD storage affects performance
The SSD technology and capacity in a smartphone has a significant influence on several aspects of real-world performance and usability:
- Faster boot times – Phones with UFS or NVMe SSDs can boot up in as little as 20-30 seconds, versus 60+ seconds for eMMC drives.
- Snappier app loading – Apps and games load faster on high-speed UFS/NVMe SSDs compared to slower eMMC options.
- Quick camera captures – Fast SSDs allow phones to quickly save high-resolution photos and process HDR, Portrait, and Night modes.
- Responsiveness – Top-tier SSD solutions deliver a very responsive experience when multitasking and navigating menus.
- Future-proofing – More storage headroom from a 256GB/512GB SSD allows you to keep the phone longer before filling it up.
In most cases, you don’t need to dive into the technical SSD specs for a phone. Just know that higher-end phones tend to use UFS or NVMe drives, while cheaper phones have eMMC storage. Overall system speed and smoothness will come down to the combination of SSD type, capacity, and the phone’s processor performance.
SSD reliability vs. HDD failures
With no moving parts, SSDs are far more reliable and resistant to failure than mechanical HDDs. However, SSDs still have a finite lifespan and their storage cells will slowly wear out over time after excessive writing. Thankfully, modern SSDs last many years even with heavy usage, and smartphones don’t write as much data as PCs.
Assuming normal usage patterns, you can expect an SSD-equipped phone to last 3-5 years with negligible degradation or slowdown. Dropping or damaging a phone can potentially cause SSD failure, but that holds true for any component. Overall, SSD reliability should not be a concern under normal conditions compared to the high failure rate seen in PC/laptop HDDs after just a few years of use.
SSD controllers and firmware
Every SSD has a built-in controller that handles operations like reading/writing data, wear leveling, garbage collection, and more. The controller is like the SSD’s brain. Many companies develop their own proprietary SSD controllers to pair with their NAND flash memory chips. For example, Samsung phones use Samsung SSD controllers.
The SSD controller firmware is the coding that gives instructions to the controller. Manufacturers periodically release firmware updates that squash bugs, improve performance, and add features. Phones can install SSD controller firmware updates just like any other software update. Keeping the SSD firmware updated is important for getting the latest optimizations and fixes.
Encryption and data security
Data stored on smartphone SSDs is automatically encrypted by default using algorithms like AES, PKCS, and FDE. This guards your personal data if someone tries to physically access the SSD by transferring it to another device. Full-disk encryption has become standard on phones from all major brands, so you can rest assured your info is protected if your phone ends up in the wrong hands. Beyond encryption, SSDs are more resilient to data recovery compared to HDDs if you were to reformat the drive.
Smartphones universally rely on NAND-based flash SSDs rather than mechanical hard drives for internal storage. Top-tier phones use UFS or NVMe SSDs focused on speed, while cheaper phones stick with eMMC drives that prioritize cost-effectiveness. There is also variability in SSD storage capacity from 16GB on the low end up to 512GB on premium phones. MicroSD card slots provide removable expandable storage, but with drawbacks around speed and reliability. Regardless of the specific SSD hardware and capacity, smartphones offer major usability, responsiveness, and reliability advantages by using solid state flash storage rather than old-fashioned hard disk drives.