Silicon Power UD90 500GB — Budget PCIe 4.0 NVMe SSD Review
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.
The UD90 is built on the Phison PS5021-E21T, a four-channel DRAM-less PCIe 4.0 x4 controller manufactured on a 12 nm process — the same platform used by the Crucial P3 Plus and Kingston NV2. Silicon Power pairs it with Micron 176-layer 3D TLC NAND, a notable choice at this price tier where competing drives increasingly ship with QLC. The drive is DRAM-less, relying on Host Memory Buffer to borrow system RAM for the flash translation layer, and uses a single-sided M.2 2280 PCB with no factory heatsink.
The 500 GB variant is the entry point of the UD90 family, sitting below the 1 TB, 2 TB, and 4 TB capacities. Rated speeds are 4,800 MB/s read and 4,200 MB/s write — figures that approach the E21T's ceiling and place the UD90 near the top of the DRAM-less Gen4 class. Endurance is 600 TBW, a 1,200-TBW-per-terabyte ratio that is unusually generous for a budget DRAM-less drive and likely reflects Silicon Power's decision to use TLC NAND rather than cost-cutting with QLC. The 1 TB and 2 TB models scale endurance to 1,200 TBW and 2,400 TBW respectively, maintaining the same per-terabyte ratio.
In the budget PCIe 4.0 segment, the UD90 competes against the Crucial P3 Plus, Kingston NV2, and Team Group MP44L — all DRAM-less Gen4 designs targeting value-conscious buyers. The UD90's key advantage is the TLC NAND, which avoids the post-cache write cliff and endurance penalty of QLC-based competitors like the P3 Plus. For a budget OS drive, the UD90 delivers Gen4 responsiveness and TLC reliability at pricing that often undercuts DRAM-equipped PCIe 3.0 alternatives, making it one of the strongest value propositions in the entry-level NVMe market.
✅ Storage Comparisons:
🚀 Performance and benchmarks
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.
Silicon Power UD90 500 GB 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.
- PNY XLR8 CS3140 1 TB: 7,500 MB/s read, 5,650 MB/s write
- PNY XLR8 CS3140 2 TB: 7,500 MB/s read, 6,850 MB/s write
- Asgard AN4 512 GB: 7,500 MB/s read, 5,500 MB/s write
- Asgard AN4 1 TB: 7,500 MB/s read, 5,500 MB/s write
- Silicon Power UD90 500 GB (this drive): 4,800 MB/s read, 4,200 MB/s write
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 and 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.
📊 Specs
| Category | Value |
|---|---|
| Capacity [?] | 500 GB |
| Interface [?] | M.2 4.0 x 4 |
| Controller [?] | Phison E21T |
| Memory type [?] | Micron TLC |
| DRAM [?] | n/a |
| Read speed (MB/s) [?] | 4800 |
| Write speed (MB/s) [?] | 4200 |
| Read IOPS [?] | 739000 |
| Write IOPS [?] | 739000 |
| Endurance (TBW) [?] | 600 |
| MTBF (million hours) [?] | n/a |
| Warranty (years) [?] | 5 |
Conclusion
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.
+ 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
🛒 Buy this or similar SSD Storage:
✨ Video Review
Silicon Power UD90 - Much Faster Than What They Wrote!
