# How much RAM does ScyllaDB use?

**URL:** <https://forum.scylladb.com/t/how-much-ram-does-scylladb-use/5265>\
**Category:** ScyllaDB\
**Tags:** configuration, memory\
**Created:** [February 3, 2026, 8:58am UTC](https://forum.scylladb.com/t/how-much-ram-does-scylladb-use/5265 "2026-02-03T08:58:56Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Guy](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.scylladb.com/guy/32/9_2.png) [@Guy](https://forum.scylladb.com/u/Guy)\
**Post date:** [February 3, 2026, 8:58am UTC](https://forum.scylladb.com/t/how-much-ram-does-scylladb-use/5265/1 "2026-02-03T08:58:56Z")

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> [@](#):
>
> **[Originally from the User Slack](https://scylladb-users.slack.com/)**
> 
> ![Vinoth_Rajendran](https://us1.discourse-cdn.com/flex016/uploads/scylladb/original/2X/0/0ffa6e6b52f0cd7b662d74acbfa516091b736f0f.png) @Vinoth\_RajendranVinoth\_Rajendran\*\*:\*\* Hi Team,  
> If we do not specify explicitly, how much percentage of RAM does Scylla DB service consume?
> 
> ![Felipe_Cardeneti_Mendes](https://us1.discourse-cdn.com/flex016/uploads/scylladb/original/1X/233a9d524fbc97e39f08633c16b3dd2575d1d1f4.jpeg) @Felipe\_Cardeneti\_Mendes\*\*:\*\* \> By default, the machine’s **entire memory** except a certain reservation left for the OS (defaulting to the maximum of 1.5G or 7% of total memory) is pre-allocated for the application in this manner. This default can be changed by **either** changing the amount reserved for the OS (not used by Seastar) with the `--reserve-memory` option, or by explicitly giving the amount of memory given to the Seastar application, with the `-m` option.