# Silicon Power UD90 500GB — Budget PCIe 4.0 NVMe SSD Review (2026)

The Silicon Power UD90 500 GB is a Phison E21T-based DRAM-less PCIe 4.0 drive that punches above its budget pricing, delivering Gen4 read speeds with TLC endurance at a cost that undercuts most SATA competitors.

Quick answer: The Silicon Power UD90 500 GB is the budget PCIe 4.0 drive to beat. Its Phison E21T + Micron TLC combination delivers Gen4 read speeds, avoids the QLC write cliff that plagues competitors at this price, and backs it all with a 600 TBW endurance rating and five-year warranty that read like a mid-range spec sheet rather than an entry-level one. The DRAM-less design and four-channel controller mean it will never match a Samsung 990 Pro on sustained mixed I/O, but for the OS-and-applications workload a 500 GB drive is meant for, the UD90 delivers everything a value-conscious buyer needs and nothing they should worry about. Buyers needing more capacity should look at the 1 TB UD90 — it shares the same performance ceiling with double the endurance at a proportional price increase.

## Specifications

| Specification | Value |
| --- | --- |
| Capacity | 500 GB |
| Interface | M.2 4.0 x 4 |
| Controller | Phison E21T |
| Memory type | Micron TLC |
| DRAM cache | HMB |
| Sequential read | 4800 MB/s |
| Sequential write | 4200 MB/s |
| Random read IOPS | 739000 |
| Random write IOPS | 739000 |
| Endurance | 600 TBW |
| MTBF | 1500000 |
| Warranty | 5 years |

## Performance

Silicon Power rates the 500 GB UD90 at 4,800 MB/s sequential reads and 4,200 MB/s sequential writes with 739,000 IOPS on both random read and write. The E21T's four-channel design limits peak throughput compared to eight-channel DRAM-equipped alternatives, but the numbers are more than sufficient for any consumer workload short of sustained sequential data ingest.

The E21T's pseudo-SLC cache on the 500 GB model absorbs roughly 40–60 GB of burst writes before transitioning to native TLC speeds around 800–1,000 MB/s. This is a critical advantage over QLC-based competitors at the same price: where the Crucial P3 Plus drops to ~100 MB/s after its cache fills, the UD90 maintains SATA-SSD-class speeds. For a boot drive, this means OS updates, application installs, and moderate file transfers never encounter a painful write cliff. Gaming load times are indistinguishable from any other PCIe 4.0 drive, and the TLC NAND means even sustained game installs from a fast internet connection complete at reasonable speeds. The DRAM-less HMB design introduces a small latency penalty under sustained mixed I/O, but for the predominantly read-heavy workload of an OS drive, this is invisible in everyday use.

## Endurance, TBW & Warranty

Silicon Power covers the UD90 500 GB with a five-year warranty, limited by a generous 600 TBW endurance rating. At 30 GB/day, this endurance budget spans roughly 55 years — remarkable for a budget DRAM-less drive. The 1,200-TBW-per-terabyte ratio is competitive with DRAM-equipped premium drives and far exceeds the QLC-based competition. The 1 TB model carries 1,200 TBW and the 2 TB reaches 2,400 TBW. Silicon Power's warranty process operates through regional RMA centres with turnaround times that vary by location. The combination of TLC NAND, high TBW, and a five-year warranty makes the UD90 one of the best-protected purchases in the budget NVMe segment.

## Pros and Cons

**Pros:**

- 4,800 MB/s reads — PCIe 4.0 throughput at a budget price
- Micron 176-layer TLC NAND — no QLC write cliff or endurance penalty
- 600 TBW endurance — 1,200 TBW/TB, unusually high for a budget drive
- 5-year warranty — exceeds most budget SSD competitors
- Single-sided M.2 2280 — fits thin laptops and compact builds
**Cons:**

- DRAM-less HMB design — sustained mixed I/O trails DRAM-equipped drives
- Four-channel E21T controller limits peak throughput vs eight-channel alternatives
- No factory heatsink — bare PCB with no thermal mitigation
- Silicon Power RMA infrastructure varies by region


## Verdict

The Silicon Power UD90 500 GB is the budget PCIe 4.0 drive to beat. Its Phison E21T + Micron TLC combination delivers Gen4 read speeds, avoids the QLC write cliff that plagues competitors at this price, and backs it all with a 600 TBW endurance rating and five-year warranty that read like a mid-range spec sheet rather than an entry-level one. The DRAM-less design and four-channel controller mean it will never match a Samsung 990 Pro on sustained mixed I/O, but for the OS-and-applications workload a 500 GB drive is meant for, the UD90 delivers everything a value-conscious buyer needs and nothing they should worry about. Buyers needing more capacity should look at the 1 TB UD90 — it shares the same performance ceiling with double the endurance at a proportional price increase.

## Frequently Asked Questions

### Is the Silicon Power UD90 500GB good for gaming?

The UD90 500 GB delivers fast game load times that are indistinguishable from any other PCIe 4.0 drive in real-world use. The 4,800 MB/s reads are well beyond what current game engines require, and the TLC NAND ensures game installs complete at reasonable speeds without the post-cache performance collapse that QLC drives suffer. The 500 GB capacity fits the OS plus a small game library — two to four AAA titles depending on size. For a dedicated gaming drive, the 1 TB or 2 TB UD90 provides more breathing room at a proportional price increase.

### Does the UD90 use TLC or QLC NAND?

The UD90 uses Micron 176-layer 3D TLC NAND. This is a significant advantage over QLC-based budget competitors like the Crucial P3 Plus. TLC stores three bits per cell versus QLC's four, which translates to higher write endurance, faster native (post-cache) write speeds, and better sustained performance under mixed workloads. The TLC choice is the UD90's single biggest differentiator in the budget NVMe segment and the reason its endurance rating (1,200 TBW/TB) is competitive with premium DRAM-equipped drives.

### Does the Silicon Power UD90 have a DRAM cache?

No, the UD90 is a DRAM-less SSD using Host Memory Buffer (HMB) technology. The Phison E21T controller borrows a portion of system RAM for the flash translation layer mapping tables, eliminating the cost of a dedicated DRAM chip. For everyday OS and application use, the HMB approach is transparent — Windows boots, applications launch, and files transfer without any perceptible difference versus a DRAM-equipped drive. Sustained mixed read-write workloads benefit from dedicated DRAM, but these scenarios are uncommon on a budget 500 GB boot drive.

### What is the TBW endurance of the UD90 500GB?

The UD90 500 GB is rated for 600 TBW, which translates to roughly 329 GB of writes per day over the five-year warranty period. This is an unusually high 1,200-TBW-per-terabyte ratio for a budget DRAM-less drive, exceeding many premium DRAM-equipped SSDs. At a typical consumer write rate of 20 GB/day, the endurance budget lasts roughly 82 years. The high TBW rating reflects the Micron 176-layer TLC NAND's durability and Silicon Power's confidence in the E21T platform.

### How does the UD90 compare to the Crucial P3 Plus 500GB?

Both are DRAM-less PCIe 4.0 drives built on the same Phison E21T controller, but the UD90 uses TLC NAND while the P3 Plus uses QLC. This is a fundamental difference with real consequences: the UD90's post-cache write speed (~800 MB/s) is roughly eight times the P3 Plus's (~100 MB/s), and its 600 TBW endurance is over five times the P3 Plus's 110 TBW at the same capacity. Peak reads are similar (4,800 vs 4,700 MB/s). The P3 Plus counters with a higher maximum capacity ceiling (4 TB vs the UD90's 4 TB). For any buyer who writes more than occasionally, the UD90 is the unequivocally better choice — the TLC vs QLC difference is the single most important spec in the budget NVMe segment.

---

Last updated: 2026-05-23. Source: https://ssdrive.net/silicon-power-ud90-500-gb