Fanxiang S660 1TB Review — Budget PCIe 4.0 with QLC Trade-Offs (2026)
Quick answer
The Fanxiang S660 1 TB is a defensible choice for a budget game library drive or a secondary storage device where every file on it has a backup elsewhere.
Read: 5000 MB/s Write: 4500 MB/s Endurance: 800 TBW Warranty: 5 years Interface: M.2 4.0 x 4
The Fanxiang S660 1 TB is the capacity where this budget QLC drive starts to make practical sense — enough space for a real game library, enough NAND parallelism to hit its rated speeds, and a price that undercuts nearly everything with a PCIe 4.0 label.
Controller & Memory
The S660 pairs a Phison PS5021-E21T — the same 4-channel DRAM-less controller found in the Crucial P3 Plus — with Micron 176-layer QLC NAND. There is no onboard DRAM; the drive borrows 64 MB of system memory via HMB for its mapping tables. The PCB is single-sided M.2 2280, which is one of the S660's best practical features: it fits in thin laptops, the PS5 expansion bay, and compact Mini-ITX builds where double-sided drives cause clearance headaches.
This 1 TB variant sits in the middle of the S660 stack, which runs from 512 GB up to 4 TB. At 1 TB you get enough NAND dies to saturate the rated 5,000 MB/s reads and 4,500 MB/s writes, which the 512 GB model may not fully achieve due to reduced parallelism. The larger capacities offer higher endurance ratings and larger SLC cache buffers, but the core performance profile is consistent across the family.
In the budget PCIe 4.0 segment, the S660 1 TB goes head-to-head with the Crucial P3 Plus, Silicon Power UD90, and Team Group MP44Q — all DRAM-less QLC drives built on the same E21T or similar controllers. The S660's differentiator is price, but the Crucial and Team Group options offer more predictable after-sale support and consistent component sourcing.
Storage Comparisons:
S660 Performance & Benchmarks
Rated at 5,000 MB/s sequential reads and 4,500 MB/s sequential writes, the S660 1 TB delivers respectable PCIe 4.0 throughput for light-to-moderate workloads. Random IOPS land around 600,000 reads and 500,000 writes — sufficient for boot, gaming, and general productivity, though the HMB-only design means sustained mixed-I/O consistency falls short of DRAM-backed alternatives.
Fanxiang S660 1 TB vs M.2 4.0 x 4 peers
Switch between sequential throughput and random IOPS to see how this drive stacks up against other M.2 4.0 x 4 SSDs in our database. The highlighted bar is the drive on this page — click any other bar to open that drive.
- Patriot Viper PV593 1 TB: 14,500 MB/s read, 14,000 MB/s write
- Patriot Viper PV593 2 TB: 14,500 MB/s read, 14,000 MB/s write
- Patriot Viper PV593 4 TB: 14,500 MB/s read, 14,000 MB/s write
- Patriot Viper PV573 2 TB: 14,000 MB/s read, 12,000 MB/s write
- Fanxiang S660 1 TB (this drive): 5,000 MB/s read, 4,500 MB/s write
The S660's performance story is defined by what happens after the SLC cache fills. The pseudo-SLC write buffer handles burst writes at full speed, but once exhausted — which happens sooner on a QLC drive than a TLC equivalent — write speeds collapse to roughly 1,400 MB/s during the cache folding phase and eventually settle around 530 MB/s at native QLC speed. For gaming and everyday use this is a non-issue; game installs are mostly reads, and background writes are small and intermittent. For anyone regularly transferring 100 GB+ of video or raw photos, the write cliff will be frustratingly apparent.
Fanxiang S660 vs Competitors
See how the S660 stacks up against other M.2 4.0 x 4 drives in our database:
Compare with rival drives:
Endurance, TBW & Warranty
Fanxiang claims a 5-year warranty, though the S660 is conspicuously absent from the company's own website. The 1 TB endurance is not officially published, but scaling from the 4 TB model's confirmed 2,800 TBW yields an estimated 800 TBW at this capacity. At a typical 30 GB per day, that is over 70 years of writes. The numbers look fine on paper. The real-world concern is Fanxiang's support track record: user reviews report drives failing within weeks and RMA requests going unanswered. A warranty you cannot claim is not a warranty.
Fanxiang S660 1 TB Specifications
| Category | Value |
|---|---|
| Capacity [?] | 1 TB |
| Interface [?] | M.2 4.0 x 4 |
| Controller [?] | Phison PS5021-E21T 4 Channel |
| Memory type [?] | Micron 176-L QLC |
| DRAM [?] | No |
| Read speed (MB/s) [?] | 5000 |
| Write speed (MB/s) [?] | 4500 |
| Read IOPS [?] | 600000 |
| Write IOPS [?] | 500000 |
| Endurance (TBW) [?] | 800 |
| MTBF (million hours) [?] | 1500000 |
| Warranty (years) [?] | 5 |
Verdict: Is the S660 Worth It in 2026?
The Fanxiang S660 1 TB is a defensible choice for a budget game library drive or a secondary storage device where every file on it has a backup elsewhere. Its single-sided PCB, included heatsink, and rock-bottom price make it appealing for PS5 expansion on a tight budget — though it falls short of Sony's 5,500 MB/s recommended read speed. Buyers who need a primary boot drive or who value having a company that answers support tickets should spend the small premium for a Crucial P3 Plus or Team Group MP44Q instead.
+ Pros
- 5,000 MB/s reads and 4,500 MB/s writes on PCIe 4.0
- Single-sided PCB fits thin laptops and the PS5 M.2 bay
- Includes heatsink, pads, screwdriver, and M.2 screw
- 5-year warranty period with ~800 TBW estimated endurance
- Aggressively priced against name-brand QLC alternatives
- Cons
- QLC NAND with severe post-cache write drop to SATA-class speeds
- DRAM-less HMB design struggles with sustained mixed workloads
- Marketed as TLC on some listings but confirmed as QLC via Flash ID
- Warranty support is effectively unreachable per widespread user reports
- Below Sony's 5,500 MB/s PS5 recommended read speed floor
Buy this or similar SSD Storage:
Video Review
fanxiang S660 1TB SSD Review – Best Budget PS5 SSD?
