In the olden days, everyone taking their hardware seriously also had scratch disks. But they're currently considered to be from a bygone era.
Some people still use them, though. But should you?
What's a scratch disk?
Patrick Campanale / How-To Geek
A scratch disk is a specialized portion of hard drive space, or a separate hard drive, that serves as a temporary storage facility for computer programs, most notably resource-intensive creative software. When you run apps for video editing, 3D modeling, or high-resolution graphic design, the computer's RAM is the first line of defense for storing immediate data.
However, RAM is a finite resource. When a project becomes too complex or the file sizes exceed the available physical memory, the software requires an alternative location to offload data that is currently in use but cannot fit in the RAM.
This overflow area is the scratch disk. It essentially functions as virtual memory, allowing the application to continue operating without crashing, even when the system's primary memory is completely saturated with data.
In technical terms, this process involves the creation of temporary cache files, history states, and undo data. For example, every time a digital artist applies a filter in Photoshop or a video editor renders a preview in Premiere Pro, the software generates temporary files that allow the user to revert changes or scrub through a timeline. If the designated scratch disk is the same drive running the operating system, the computer must simultaneously read system files, launch applications, and write these heavy temporary files.
This leads to a competition for the drive's bandwidth. A dedicated scratch disk solves this by being a physically separate drive—distinct from the partition storing the operating system or the permanent project files—solely assigned to handle this high-volume, high-frequency temporary read-and-write traffic. It's kind of like a "working" drive, designed to be filled with temporary data during a session and often wiped clean once the application is closed.
Why are they a good option?
Patrick Campanale / How-To Geek
By physically separating temporary cache operations from the operating system and project files, users eliminate a significant data bottleneck known as drive contention. In a single-drive setup, the storage controller is constantly besieged by requests to read operating system logs, load application binaries, and simultaneously write massive temporary cache files. This multitasking forces the drive to split its bandwidth, often resulting in system lags, stuttering video playback, or the dreaded "spinning wheel" during complex rendering tasks. A dedicated scratch disk isolates the chaotic, heavy-write workload of temporary files, leaving the main system drive free to run the OS and applications smoothly while a secondary drive handles the project assets.
Beyond immediate speed improvements, utilizing a dedicated scratch disk significantly extends the lifespan of a primary solid-state drive (SSD). Modern SSDs have a finite lifespan measured in Terabytes Written (TBW). Creative workflows are notoriously destructive in this regard; a video editor might generate hundreds of gigabytes of render files in a single day, only to delete them hours later.
If this constant cycle of writing and deleting occurs on the main OS drive, it rapidly consumes the drive's endurance rating, potentially leading to premature hardware failure. By offloading this "junk" traffic to a dedicated scratch disk, you protect your more critical, often more expensive, primary NVMe drives that house the operating system and essential apps.
Should I buy one in 2026?
Patrick Campanale / How-To Geek
The necessity of a dedicated scratch disk in 2026 is a nuanced subject that largely depends on the specific intensity of a user's workflow and the architecture of modern storage. With the prevalence of PCIe Gen 5 and Gen 6 NVMe SSDs, transfer speeds have reached heights that were unimaginable a decade prior. These modern drives offer bandwidth so massive that the traditional bottlenecks of reading and writing simultaneously are significantly mitigated for the average user.
For general computing, gaming, or even light photo editing, the sheer speed of a single modern high-end drive renders the concept of a dedicated scratch disk largely obsolete. If a system is equipped with substantial amounts of high-speed DDR5 or DDR6 RAM, the software rarely needs to page out to the disk, further reducing the need for separate temporary storage.
However, for professional creatives pushing the boundaries of technology, the case for a dedicated scratch disk remains compelling. As storage speeds have increased, so too have the demands of file formats. In 2026, professionals are routinely handling 8K and 12K RAW video footage, engaging in complex photogrammetry, and running local AI models that require massive paging files. These tasks generate temporary data that can easily overwhelm even substantial RAM configurations.
In these high-pressure scenarios, physics still applies; splitting the I/O load across multiple physical channels provides a tangible stability benefit. Furthermore, the economic argument remains valid. High-performance, high-capacity OS drives are expensive. Utilizing a cheaper, high-endurance dedicated drive for the sole purpose of absorbing the wear and tear of temporary cache files is a prudent financial decision for anyone generating terabytes of disposable data monthly.
Casual users can skip it, but professional workstation builders in 2026 should still consider a dedicated scratch disk a standard component of a balanced system. You might just need it.
