I know what you’re thinking—flash drives don’t have batteries! While that may be true, you may have come across a flash drive that either loses data or performs poorly compared to others—like the one you fished out of your junk drawer after a year.
Flash drives don’t contain batteries but are still electronic devices. Essential Garbage Collection (GC) processes happen in the background while the device is plugged in. Most flash drives are only plugged in momentarily to transfer data, leading to data loss and performance degradation.
While it isn’t the same as charging a battery, you have to leave the device plugged into your computer for a spell so it can accomplish these background tasks. Read on for more information about these processes and why you should charge flash drives periodically.
Why You Need To Charge Your Flash Drive
Solid state memory may seem nigh-indestructible, especially compared to the almost pitifully fragile hard disk type drives (HDDs). They are, however, vulnerable in their own way.
Here are some issues you may experience if you do not “charge” your flash drives:
- Data corruption. Many people don’t eject flash drives safely, leading to the entire drive getting corrupted.
- Slow performance. A flash drive that has not completed Garbage Collection processes will transfer data slowly
- Drive failure. With enough misuse, the flash drive can fail. A failed drive may seem to hold data but become instantly corrupted or performs erratically even if you eject it correctly.
- Poor data retention. A misused flash drive will lose charge faster than expected, resulting in data loss or corrupted files, especially if exposed to heat.
A flash drive can withstand a certain level of misuse – users may plug it in and pull it out without ejecting correctly many times before experiencing any issues. The reason for this is that the damage is cumulative. That’s why your old reliable thumbstick that has been attached to your keys for the last few years might be nothing more than a keyring at this stage.
Why Ejecting Flash Drives Correctly Is Important
I have alluded to Garbage Collection already. To understand why flash drives need to be “charged”, you need to know what they do in the background. You may have noticed that even when the drive is idle, the lights (if installed) flash as if it’s still transferring data.
It’s important to eject flash drives correctly because pulling them out without warning may lead to data corruption. The motion interrupts the Garbage Collection and Wear Leveling processes which could damage cells on your flash drive, making it slow and unreliable. You may also lose data.
It only takes a few seconds to eject a flash drive properly. Getting into the habit of doing this before you remove the USB stick might save you from losing critical data one day. Like any electronic device, flash drives usually work until they don’t anymore.
What Is the Garbage Collection (GC) Process?
Flash drives are designed to facilitate quick data transfer. However, they are prone to accumulating trash data, similar to how HDDs can become fragmented.
Garbage Collection on flash drives is a background process that arranges data so that it can be read and re-written more efficiently. This also usually includes a process called wear leveling, which is intended to prolong the service life of the drive.
Memory blocks have to be written and erased piecemeal, and it can take some time for Garbage Collection to take place, especially with a drive that is frequently rewritten. Pulling a drive out and interrupting this process can leave you with bad sectors. To learn more about this, check out this article.
What Is Wear Leveling?
Solid-state memory might not have the mechanical wear limitations of their hard disk-type counterparts. However, the segments on which data is stored have a limit on the number of times you can rewrite data on them.
Wear leveling is a background process that tries to balance the number of times each memory block on your flash drive is used. If this background process does not take place, your drive will probably rewrite the same blocks all the time and begin to degrade.
You can think of wear leveling as analogous in a way to rotating pairs of shoes. If you wear the same pair every day, they will break while leaving your other pair shiny and new. If shoes were more like flash memory, the broken pair would prevent you from wearing the new ones in some cases. For more on this, check out my article; Do USB Flash Drives Have Wear Leveling?
SSDs Also Require Garbage Collection
Like flash drives, SSDs are based on NAND flash memory and primarily have the same vulnerabilities. The main difference is you’re more likely to leave an SSD plugged in—either directly to your SATA controller or, in the case of an M.2, to a dedicated PCIe slot.
If you are using an external SSD, garbage collection and wear leveling also occur in the background on these devices. Due to the larger capacity, it’s usually much less noticeable when blocks begin to fail. Still, you can end up with an SSD that is prone to data loss and corruption if you do not allow these processes to take place.
Most of the time, SSDs will not fail outright like some USB flash drives—they will begin accumulating bad sectors, which are unusable memory blocks that have been damaged or worn out.
NAND Flash Data Retention
Garbage collection and wear leveling are not the only enemies of flash memory. The truth is, these devices do, in fact, lose charge over time. Manufacturers may indicate a value of some sort here, usually around 10 years.
Flash data retention can degrade depending on how the device is used and is also influenced by storage temperature and pressure. A device that is allowed to complete all its garbage collection and wear leveling processes will almost always last longer than one that is only plugged in long enough to transfer data.
Memory sticks should always be stored at a stable temperature. At high temperatures, the electrical charge degrades much faster. This may explain why the flash drive you left on your car’s dashboard for a few days doesn’t seem to work as well as it used to.
Some Flash Memory Types Are More Reliable Than Others
They might all look similar, but there are different types of flash memory. And they all have their pros and cons, as follows:
- Single Level Cell (SLC) NAND. This is considered industrial-grade flash memory, containing 1 bit per cell. It is more expensive than other flash memory types and has lower capacities but has high endurance at around 100,000 P/E cycles.
- Multi-Level Cell (MLC) NAND. Adequate for most uses, you will get an endurance of 10,000 P/E cycles and faster read/write speeds. MLC NAND stores 2 bits per cell.
- Triple-Level Cell (TLC) NAND. Storing 3 bits per cell, TLC NAND offers massive capacities but lacks endurance with only 3,000 P/E cycles. It is also the cheapest NAND memory type.
Depending on your use case, you’ll want to make sure you’re using the right NAND type for your needs. SLC is recommended for critical data and files you cannot afford to lose, with MLC being a good middle-ground between SLC and the low-endurance TLC NAND.
Like with any information technology, there is always room for improvement. Newer standards like Samsung’s V-NAND (sometimes referred to as 3D-NAND) will not be covered here since this type of memory structure is relatively uncommon at the time of writing.
How To Charge Your Flash Drive
This question might seem like asking how long is a piece of string. This is because there are no hard-and-fast rules or manufacturer recommendations telling you how or why you are charging your flash drive.
Flash drives should be plugged into a computer for an hour or more to allow the controller to carry out garbage collection and wear leveling. You don’t need to do this every time you use the flash drive, but you should always eject the media correctly.
If you are storing flash drives (especially if you aren’t sure of their condition), you should periodically plug them into a computer every 6 months or so. This will help you verify the integrity of the stored data and prevent any data retention issues.
It might seem ridiculous to charge something that doesn’t even contain a battery. Nonetheless, there are a few good reasons to leave your flash drive plugged in a while longer than you usually would rather than unceremoniously ripping it out.
Allowing your drive to carry out necessary garbage collection and wear leveling processes will ensure it lasts longer, especially if you are careful to store it away from any heat sources.
Always remember to eject the flash drive properly to avoid interrupting these processes—you’re not just risking your data, but also destroying your flash drive.