DRAM cache
A small DDR memory chip on an SSD that stores the flash translation layer (FTL) map. Drives with DRAM have predictable random-access performance; DRAM-less drives degrade under heavy use.
An SSD's flash translation layer maps logical block addresses to physical NAND locations. With every write the map updates. Storing this map in fast DRAM keeps random I/O predictable.
DRAM-less drives
Budget SSDs omit DRAM and instead use Host Memory Buffer (HMB) — a slice of system RAM allocated by the NVMe driver. Performance is fine for light use but degrades as the drive fills past 70%, especially on random 4K workloads.
How to spot a DRAM-less drive
- Marketing rarely mentions it.
- Tear-down photos and review databases (techpowerup, tomshardware) list the controller and cache config.
- Price: drives well under $50/TB are usually DRAM-less.
In comparisons
For a OS / game drive, DRAM-less is fine. For a daily-driver SSD that will fill to 80%+, DRAM-equipped drives stay snappy years into use. The TLC + DRAM combination is the modern enthusiast baseline.
How to use DRAM cache in a real comparison
A small DDR memory chip on an SSD that stores the flash translation layer (FTL) map. Drives with DRAM have predictable random-access performance; DRAM-less drives degrade under heavy use. In practice, this is most useful as one part of a decision rather than a standalone quality badge. Compare it alongside the workload, room, ecosystem, budget, and ownership constraints that apply to you; the strongest published figure is not automatically the best outcome for every buyer.
What to check next
Open a product page and check the stated value, configuration, price, and related trade-offs before treating this term as decisive. It is especially relevant in .
Avoid the one-number trap
Manufacturers can describe the same capability under different conditions. Compare like-for-like variants, check the unit and test condition where available, and use a head-to-head page to see whether a measurable difference is material for your own use.
vsMars presents structured catalog values to make trade-offs legible. The linked product and spec pages are the right place to inspect the underlying values before buying.