# Fanxiang S770 1TB Review — PCIe 4.0 NVMe with DRAM Cache (2026)

The Fanxiang S770 1 TB is a PCIe 4.0 drive that looks like a flagship on paper but comes with the kind of quality-control asterisks that make a buyer pause — here is what you actually get.

Quick answer: The Fanxiang S770 1 TB is the right pick for a buyer who wants flagship-adjacent sequential speeds at a budget price and can tolerate a support and quality-control lottery. It belongs in a gaming rig or as a fast secondary drive where the data is backed up elsewhere. Buyers who value long-term reliability, consistent component sourcing, and reachable warranty support should stretch to a Silicon Power US75 or Kingston NV3 instead — both offer comparable performance from companies with established RMA pipelines. The S770 is a capable drive let down by the company behind it.

## Specifications

| Specification | Value |
| --- | --- |
| Capacity | 1 TB |
| Interface | M.2 4.0 x 4 |
| Controller | Innogrit IG5236 |
| Memory type | YMTC 128-l TLC |
| DRAM cache | Yes |
| Sequential read | 7300 MB/s |
| Sequential write | 5400 MB/s |
| Random read IOPS | 860000 |
| Random write IOPS | 675000 |
| Endurance | 700 TBW |
| MTBF | 2000000 |
| Warranty | 5 years |

## Performance

The S770 1 TB is rated for 7,300 MB/s sequential reads and 5,400 MB/s sequential writes over PCIe 4.0 x4, with random IOPS in the neighbourhood of 860,000 reads and 675,000 writes. Those numbers put it in the same postcode as first-wave PCIe 4.0 flagships — impressive for a budget-brand drive, though the gap between rated and sustained performance matters here.

Like most modern NVMe drives, the S770 uses a pseudo-SLC write cache to hit its advertised speeds. Once that cache fills — on the 1 TB model, independent testing suggests roughly 340 GB of cache capacity — write performance drops to native TLC speed, which is substantially lower. For a typical gaming or boot-drive workload this is invisible; the cache recovers during idle periods and most transfers are well under the cache threshold. For sustained large-file workflows like 4K video ingest or multi-hundred-gigabyte game library migrations, the post-cache dip is noticeable. This is not unique to the S770 — it is standard NVMe behaviour — but it is worth knowing if your workload involves frequent large transfers.

## Endurance, TBW & Warranty

Fanxiang backs the S770 1 TB with a 5-year warranty capped at 700 TBW of endurance. At a typical consumer workload of 30 GB per day, that works out to roughly 64 years before hitting the TBW ceiling — the warranty period will expire long before the endurance budget does. The MTBF is rated at 2 million hours, though like all MTBF figures this is a population-level statistic, not a per-drive lifespan prediction. The practical warranty concern is not the numbers on the spec sheet but Fanxiang's support track record: multiple user reports describe unresponsive customer service and warranty claims that went unanswered until Amazon intervened. For a drive storing irreplaceable data, that support gap matters more than the TBW rating.

## Pros and Cons

**Pros:**

- 7,300 MB/s sequential reads on PCIe 4.0
- Dedicated DDR4 DRAM cache, not HMB
- Includes heatsink, pads, and screwdriver in the box
- 5-year warranty with 700 TBW endurance on the 1 TB model
**Cons:**

- NAND and controller revisions swapped between production batches without notice
- Customer support is effectively unreachable for warranty claims per user reports
- Double-sided PCB may not fit thin laptops
- YMTC 128L TLC has a history of forum-reported corruption issues
- 1 TB write speed (5,400 MB/s) is a step down from the 2 TB variant (6,800 MB/s)


## Verdict

The Fanxiang S770 1 TB is the right pick for a buyer who wants flagship-adjacent sequential speeds at a budget price and can tolerate a support and quality-control lottery. It belongs in a gaming rig or as a fast secondary drive where the data is backed up elsewhere. Buyers who value long-term reliability, consistent component sourcing, and reachable warranty support should stretch to a Silicon Power US75 or Kingston NV3 instead — both offer comparable performance from companies with established RMA pipelines. The S770 is a capable drive let down by the company behind it.

## Frequently Asked Questions

### Does the Fanxiang S770 have a DRAM cache?

Yes. The S770 uses a dedicated DDR4 DRAM cache paired with the InnoGrit IG5236 controller, which is a meaningful advantage over DRAM-less HMB designs at this price point. DRAM allows the controller to store the logical-to-physical mapping table on the drive itself rather than borrowing system memory, which improves sustained random I/O consistency and reduces latency under mixed workloads.

### Is the Fanxiang S770 1TB compatible with the PS5?

Physically and electrically, yes — the S770 is a PCIe 4.0 x4 M.2 2280 drive that meets Sony's 5,500 MB/s recommended sequential read floor. However, the drive is double-sided, and the PS5's M.2 bay has limited clearance for double-sided PCBs. The included heatsink helps thermally but adds height — you will need to verify the total assembly thickness against Sony's published 11.25 mm maximum. Several Amazon reviewers report successful PS5 use at measured speeds around 6,540 MB/s, so it works, just measure first.

### What is the TBW endurance of the Fanxiang S770 1TB?

The 1 TB variant is rated for 700 TBW, which is in line with other TLC-based PCIe 4.0 drives at this capacity. At a typical consumer write load of 30 GB per day, that endurance budget would take over 60 years to exhaust — the 5-year warranty will expire first. The 2 TB model doubles endurance to 1,400 TBW.

### Does the Fanxiang S770 need a heatsink?

The IG5236 controller is known to run warm under sustained load, and the double-sided PCB with YMTC NAND concentrates heat on both sides of the board. Fanxiang includes a heatsink in the box, and you should use it — especially in a desktop with limited airflow or inside a PS5 where ambient temperatures are already elevated. Without a heatsink, the controller may throttle during extended sequential transfers.

### How does the Fanxiang S770 compare to the Silicon Power US75?

Both are PCIe 4.0 drives in the budget-to-mid-range tier with DRAM caches and rated reads in the 7,000+ MB/s range. The US75 uses a Phison E18 controller with Micron TLC, which has a longer and more consistent track record than the IG5236-YMTC pairing in the S770. Silicon Power also has a functioning RMA process in Western markets, whereas Fanxiang's support is frequently described as unresponsive. The S770 undercuts the US75 on price, but the US75 wins on predictability.

### Is the Fanxiang S770 good for gaming?

For a gaming drive, the S770 is more than fast enough. DirectStorage workloads and game load times benefit from the 7,300 MB/s sequential reads and low access latency of the DRAM-backed controller, and the difference between this and a PCIe 5.0 drive in real-world game loads is negligible. The caveat is reliability: if this is your only drive and contains saves you care about, the documented failure rate and poor support infrastructure make it a riskier pick than established brands.

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Last updated: 2026-08-10. Source: https://ssdrive.net/fanxiang-s770-1-tb