SLC vs MLC vs TLC — What NAND Cell Type Means for Your Product
SLC, MLC and TLC describe how many bits a NAND cell stores: one, two or three. Fewer bits per cell means higher endurance, faster writes and higher cost; more bits means greater density and lower cost with reduced write endurance. In practice the cell type is only part of the picture — the controller, the over-provisioning and the grade of the die affect field behaviour as much as the cell architecture does. That is why a card labelled with a cell type and nothing else still tells you less than a stated grade and source.
The three cell types
| Type | Bits per cell | Write endurance | Cost | Typical use |
|---|---|---|---|---|
| SLC | 1 | Highest | Highest | Industrial, automotive, high-write workloads |
| MLC | 2 | Moderate | Moderate | Industrial and higher-end consumer |
| TLC | 3 | Lower | Lowest | Consumer cards, cost-sensitive volume |
Why the label is not the whole answer
- The controller manages wear levelling and bad-block handling — the same cell type behaves differently under different controllers
- Over-provisioning (spare capacity held in reserve) extends usable endurance
- Die grade matters independently: a sorted, tested die is not the same as an ungraded one of the same cell type
- Sustained write behaviour depends on the cache strategy, not just the cells
What to specify instead of guessing
Specify the workload, not the acronym: how much is written per day, whether it is continuous or intermittent, the temperature range and the expected service life. A supplier can then propose a cell type and controller combination that fits, and be accountable for it. Asking for "SLC" without a workload either over-specifies or under-specifies.
Not sure which applies to your product?
Send your workload — what writes, how often, at what temperature — and we will propose a configuration with the reasoning. We reply to business enquiries within 1 business day.
Request a quoteFrequently asked questions
Do I need SLC for a dashcam?
Not necessarily. Dashcams write continuously, so endurance matters — but a well-managed TLC part with adequate over-provisioning can be a better value choice than SLC. Specify the duty cycle and let the configuration follow.
Why is SLC so much more expensive?
It stores one bit per cell, so it needs roughly three times the silicon for the same capacity compared with TLC, and it is produced in much lower volume.
Can you tell me the cell type on my order?
Yes — it is part of the configuration we confirm in writing before quoting. Tell us your workload and we will propose the cell type and controller combination for it.