How to Cut Firefox’s SSD Write Volume by Adjusting Session Store Interval

According to external reports, Firefox may write a large amount of data to solid‑state drives (SSD), sometimes exceeding the manufacturer’s recommended daily write limits. ServeTheHome’s technical expert explained that, depending on the number of open tabs and windows, a default Firefox configuration can cause daily SSD writes of 10 to 30 GB. The main culprits are the recovery.js file, which stores thread information for crash recovery, and the cookie.* files that hold per‑site cookie data.

As users browse the web, Firefox periodically updates these files, generating continuous write operations. ServeTheHome’s Sergei Bobik noted that adjusting a single Firefox setting can limit the write activity of recovery.js.

Step‑by‑Step Fix

Enter about:config in the address bar and press Enter.

Search for the entry browser.sessionstore.interval and double‑click it to edit.

The default value for browser.sessionstore.interval is 15000 ms (15 seconds). To reduce write frequency, you can increase it to 300000 ms (5 minutes) or 1800000 ms (30 minutes).

Firefox is not the only browser with this issue; Google Chrome has been reported to write about 1 GB per hour, totaling roughly 24 GB per day.

Bobik warned SSD users that the nominal daily write endurance of many SSDs is around 20 GB, and browsers like Firefox (or Chrome) can consume more than half of that amount.