Why SSD Endurance Is Dropping 67% as Capacities Grow – Is Your Drive Getting More Valuable?

Market context

After the 618 shopping festival, DDR5 memory and SSD prices rose sharply, prompting manufacturers to seek lower‑cost storage solutions. The industry is moving toward QLC NAND, which stores 4 bits per cell instead of the 3 bits of TLC, enabling higher density at reduced per‑gigabyte cost.

QLC vs. TLC technical differences

Each QLC cell holds 4 bits of data, allowing a chip of the same physical size to store more data than a TLC chip.

Higher bits‑per‑cell require tighter voltage control, resulting in slower write speeds, lower sustained performance, and reduced endurance.

Typical program/erase (P/E) cycles: TLC ≈ 1 500–3 000, QLC ≈ 300–1 000 (≈ 67 % lower endurance).

Device examples and specifications

Leaked information suggests the upcoming iPhone 18 Pro 1 TB and 2 TB models will use QLC NAND, while 256 GB and 512 GB variants remain TLC.

Samsung’s 990 SSD line mixes TLC (V8T) and QLC (B8Q) in the 1 TB model; the 2 TB model uses pure QLC (B8Q).

Samsung announced mass production of its 9th‑generation QLC V‑NAND and plans to extend QLC to consumer SSDs, smartphone UFS, and PCs.

The 990 QLC model offers sequential read/write comparable to the 990 EVO Plus but ships with a three‑year warranty and reduced warranty‑based capacity.

Intel P2 QLC showed a noticeable performance drop during prolonged sequential writes once the SLC cache was exhausted.

Solidigm P41 Plus employs a 300 GB mixed‑SLC cache, delivering up to 400 MB/s sustained write speed, which can exceed some TLC drives.

Performance characteristics

In everyday tasks such as messaging, video playback, and web browsing, most users notice little difference because modern controllers use smarter data‑placement algorithms, larger SLC caches, and aggressive caching strategies. The performance gap becomes evident during sustained writes (e.g., 4K video recording, large file transfers) when the cache is depleted, causing QLC write speeds to drop.

Industry adoption and outlook

QLC has been used in enterprise storage for years; its lower cost makes it attractive for consumer devices as storage prices remain high. Samsung’s 9th‑gen QLC V‑NAND rollout and the inclusion of QLC in flagship SSDs indicate a trend toward mainstream adoption. The author argues that QLC is not a flawed technology but a natural evolution toward higher density and lower cost, provided that controller, cache, and firmware optimizations keep the user experience close to TLC while offering more affordable pricing.

Data sources: X, Tom’s Hardware, TrendForce (集邦咨询), Samsung announcements.

Code example

来源丨
本文来自电手（ID:AoMeiDianShou），未经授权不得二次转载，如有需求请联系微信号：
18884046785
作者丨阿红
关注我们丨文末赠书