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A RAM disk reserves part of a computer’s memory and presents it as a storage volume. Applications can save files there using ordinary filesystem operations. It can be useful for temporary data, but it reduces the RAM available to everything else and normally loses its contents when power is removed.
RAM disk, cache and SSD are different
A software RAM disk uses system DRAM. An SSD stores data in non-volatile NAND flash. An operating system’s file cache uses available memory automatically and can often provide much of the benefit of repeated reads without requiring a separate RAM-disk volume.
The words “RAM disk” and “RAM drive” are sometimes used interchangeably. Historical hardware devices that use RAM as storage are a separate implementation; do not infer a required PCIe device from the name alone.
Tasks that may benefit
- Scratch files that can be regenerated after a crash.
- Short-lived build or processing work that is demonstrably limited by storage access.
- Controlled testing where you want to reduce one storage bottleneck.
The benefit depends on the application. Measure the actual task, including any initial file copy and later save, rather than relying only on a synthetic transfer-speed figure.
Why a gaming gain is not guaranteed
Loading a game involves reading, decompressing and processing data. Faster reads do not eliminate the other work. A game must also fit the RAM-disk allocation while leaving enough memory for the operating system and the game itself. There is no fixed RAM-disk speed multiplier or frame-rate gain.
For many PCs, keeping games on an SSD and leaving RAM available for the game and file cache is the simpler approach. A RAM disk can make performance worse if memory pressure causes paging elsewhere.
Work out the memory budget
Measure ordinary memory use, leave headroom for the application and allocate only the spare capacity you can afford. An illustrative 4 GB RAM disk on a 16 GB system leaves about 12 GB before other uses and implementation overhead; it does not create additional memory.
Before purchasing more RAM for this purpose, use our memory compatibility guide and check the system’s actual supported capacity. Old claims that every consumer board stops at 64 GB are not a current compatibility rule.
Persistence does not remove the risk
Some software loads an image at startup and saves it at shutdown or on a schedule. Those copies take time and require normal storage. A sudden power loss or crash can occur before the latest changes are saved. Never keep the only copy of important documents on a RAM disk.
Automatic restart settings do not protect volatile data; our power-outage restart guide explains the separate firmware behavior. For a RAM-disk experiment, use disposable files, verify the program’s startup and save settings, and restore the original memory allocation if the measured workload does not improve.