Samsung 990 EVO 2TB vs Silicon Power UD90 2TB
On the measures that settle this, Silicon Power UD90 2TB never comes out behind, and on at least one it comes out ahead.
| Specification | Samsung990 EVO 2TB | Silicon PowerUD90 2TB |
|---|---|---|
| Capacity (GB) | 2000 | 2000 |
| Sequential read (MB/s) | 5000 | 5000 |
| Sequential write (MB/s) | 4200 | 4800better |
| Current best price | £296.65at Amazon.co.uk · captured 2026-09-13 | £219.99betterat Amazon.co.uk · captured 2026-09-13 |
| Price per TB | £148.33 | £110.00better |
| Endurance (TBW) | 1200 | 1200 |
| Warranty (years) | 5 | 5 |
| DRAM cache | No | No |
| NAND type | tlc | tlc |
| Controller | Samsung Piccolo controller | Phison E21 |
How these two compare
Sequential throughput
Samsung 990 EVO 2TB is rated 5000 MB/s read and 4200 MB/s write; Silicon Power UD90 2TB, 5000 MB/s read and 4800 MB/s write. These are peak sequential rates over PCIe — the speed you would see copying one large file. For boot, app launches and everyday feel, random access matters more than this headline figure.
Price
Samsung 990 EVO 2TB lists at £296.65, or £148.33 per TB; Silicon Power UD90 2TB at £219.99, or £110.00 per TB.
Endurance
The makers warrant 1200 TBW on Samsung 990 EVO 2TB and 1200 TBW on Silicon Power UD90 2TB — how much writing each is rated to take before the endurance clause lapses. Most desktop workloads never come close, so read the two against each other rather than as a limit you are likely to reach.
DRAM cache
Samsung 990 EVO 2TB is DRAM-less; Silicon Power UD90 2TB is DRAM-less. A DRAM cache holds the drive's mapping table — the index of where each block physically sits — so the controller places and finds data without an extra flash lookup. A DRAM-less drive borrows a little system memory (HMB) or a slice of its own flash instead, and is likelier to slow once a long run of random writes outlasts its fast cache.
NAND, controller and warranty
NAND: Samsung 990 EVO 2TB uses TLC and Silicon Power UD90 2TB uses TLC. The tier is bits per cell — SLC, MLC, TLC and QLC from one to four — trading density against endurance and sustained-write speed: QLC is cheapest per gigabyte, TLC the mainstream balance, and the denser the cell the sooner sustained writes taper. On the controller: Samsung 990 EVO 2TB uses the Samsung Piccolo controller, and Silicon Power UD90 2TB uses the Phison E21. It is the chip handling error correction, wear-levelling and where each write lands — much of how a drive holds up under load — even if the part number on its own tells you little. On the cover: Samsung 990 EVO 2TB carries a 5-year warranty, Silicon Power UD90 2TB carries a 5-year warranty. The length is the maker's own vote of confidence, and on an SSD it tends to track the endurance rating — a longer warranty usually meaning more rated writes.
Which to buy
Silicon Power UD90 2TB. It gives up nothing to the other on the measures the site tracks and leads on at least one, so there is no trade to weigh — the sections above show where the margin is.
Common questions about this pair
- Which is faster, Samsung 990 EVO 2TB or Silicon Power UD90 2TB?
- Samsung 990 EVO 2TB is rated 5000 MB/s read and 4200 MB/s write; Silicon Power UD90 2TB, 5000 MB/s read and 4800 MB/s write. These are peak sequential rates over PCIe — the speed you would see copying one large file. For boot, app launches and everyday feel, random access matters more than this headline figure.
- Which costs less per terabyte, Samsung 990 EVO 2TB or Silicon Power UD90 2TB?
- Samsung 990 EVO 2TB lists at £296.65, or £148.33 per TB; Silicon Power UD90 2TB at £219.99, or £110.00 per TB.
- Should you buy Samsung 990 EVO 2TB or Silicon Power UD90 2TB?
- Silicon Power UD90 2TB. It gives up nothing to the other on the measures the site tracks and leads on at least one, so there is no trade to weigh — the sections above show where the margin is.