Silicon Power UD90 500GB vs Western Digital WD_BLACK SN770 500GB
At least one of these has no price the site currently tracks, so what follows weighs specifications alone.
| Specification | Silicon PowerUD90 500GB | Western DigitalWD_BLACK SN770 500GB |
|---|---|---|
| Capacity (GB) | 500 | 500 |
| Sequential read (MB/s) | 5000 | 5000 |
| Sequential write (MB/s) | 2700 | 4000better |
| Current best price | 133,11 €at Amazon.es · captured 2026-09-09 | — |
| Price per TB | 266,22 € | — |
| DRAM cache | No | No |
| NAND type | tlc | tlc |
| Controller | Phison E21 | — |
How these two compare
Sequential throughput
Silicon Power UD90 500GB states 5000 MB/s read and 2700 MB/s write; Western Digital WD_BLACK SN770 500GB states 5000 MB/s read and 4000 MB/s write, both over PCIe. Sequential numbers like these describe large sustained transfers; the responsiveness you notice day to day tracks random access more closely than the peak figures do.
DRAM cache
On the cache question: Silicon Power UD90 500GB is DRAM-less, and Western Digital WD_BLACK SN770 500GB is DRAM-less. The DRAM keeps the flash-translation table close, sparing a lookup on nearly every access; a drive without it leans on host memory or its own flash, which usually shows as slower sustained random writes rather than in the headline sequential numbers.
NAND, controller and warranty
On the flash itself: Silicon Power UD90 500GB uses TLC, and Western Digital WD_BLACK SN770 500GB uses TLC. NAND tiers count bits per cell — more bits pack more capacity into the same silicon but shorten write endurance and slow sustained writes, which is why QLC sits below TLC on lasting performance even when the sequential numbers match. Controller: Silicon Power UD90 500GB uses the Phison E21 and Western Digital WD_BLACK SN770 500GB's controller is not stated. The controller runs wear-levelling, error correction and the mapping table, so it shapes sustained and random behaviour as much as the flash does — though the model name alone predicts little without testing. Silicon Power UD90 500GB carries a 5-year warranty and Western Digital WD_BLACK SN770 500GB does not state one — the length the maker will stand behind the drive, and usually a proxy for the endurance it is rated to.
Which to buy
The site holds no current price for at least one of these, so it cannot call the buy on cost. Judge them on the specifications above — at the same capacity and interface, two drives usually part on things like the DRAM cache, the NAND tier, endurance and warranty, so weigh whichever of those the sections above report.
Common questions about this pair
- Which is faster, Silicon Power UD90 500GB or Western Digital WD_BLACK SN770 500GB?
- Silicon Power UD90 500GB states 5000 MB/s read and 2700 MB/s write; Western Digital WD_BLACK SN770 500GB states 5000 MB/s read and 4000 MB/s write, both over PCIe. Sequential numbers like these describe large sustained transfers; the responsiveness you notice day to day tracks random access more closely than the peak figures do.
- Should you buy Silicon Power UD90 500GB or Western Digital WD_BLACK SN770 500GB?
- The site holds no current price for at least one of these, so it cannot call the buy on cost. Judge them on the specifications above — at the same capacity and interface, two drives usually part on things like the DRAM cache, the NAND tier, endurance and warranty, so weigh whichever of those the sections above report.