What is the point of dual drives?

Dual drives refer to computer systems that utilize two separate hard disk drives or solid state drives. There are a few key potential benefits to using a dual drive setup:

Increased Storage Capacity

One of the main reasons to use dual drives is simply to have more storage space available. For example, you could have a 256GB SSD for your operating system and main applications, paired with a 2TB traditional hard drive for storing your documents, media files, etc. With everything stored locally, you don’t have to worry about cloud storage limits or relying solely on external drives.

Enhanced Performance

By dedicating one drive to the OS and apps, and the other for data storage, each drive can be optimized for different types of workloads. The OS drive can be a high-speed SSD for faster boot times and app launching, while the data drive can be a higher capacity traditional hard drive tuned for throughput over latency. This prevents the two workloads from competing for resources on a single drive.

Increased Reliability

Storing data across two separate drives provides an inherent backup in case one of the drives fails. The likelihood of both failing at the same time is extremely low. So in a dual drive setup, if one drive fails you at least still have access to the data on the secondary drive.

Ability to Upgrade Independently

With two separate drives, you can upgrade the OS drive to a larger or faster SSD without having to migrate any of your data. Likewise, the data drive can be upgraded as your storage needs grow over time. This avoids the hassle of having to clone the contents of a single drive when upgrading.

Common Dual Drive Configurations

There are a few typical setups that make effective use of dual drive systems:


This is the most popular option, with an SSD as the primary OS and app drive and a high capacity traditional hard disk drive (HDD) as the data/storage drive. The SSD provides fast performance for the components that need it most, while the HDD offers abundant cheap storage.


RAID 0 (also called striping) combines two identical drives into a single logical volume to increase performance. Data is split and written across both drives simultaneously. The total storage capacity is the sum of the two drives. RAID 0 is ideal for tasks like video editing, 3D modeling, and gaming.


RAID 1 (also called mirroring) copies data to both drives simultaneously. If one fails, the system can instantly failover to the other drive without interruption. RAID 1 doubles your read performance, but total capacity is equal to a single drive. It provides excellent redundancy for mission critical data.

SSD Caching

A small SSD can be paired with a larger HDD and configured as a cache. Frequently accessed data is stored on the fast SSD while less accessed data resides on the slower HDD. Overall performance improves while still providing abundant total storage.

Ideal Usage Scenarios

Here are some of the most common usage scenarios that can benefit greatly from a dual drive setup:

Gaming Rigs

Gamers can boot games and load levels much faster with the OS on an SSD while keeping their massive Steam library on a spacious HDD. The high capacity HDD is also great for recording gameplay videos and streaming.

Creative Professionals

Media editors need both speed and storage. The SSD enables smooth editing and quick scrubbing of high-res footage, while the HDD stores all the raw footage and finished projects. Some may even run RAID 0 for maximum performance.

General Use

Regular users can boot up in seconds with an SSD, while keeping all their personal files on the HDD. Things like photos, videos, music, and documents can quickly fill up space that would be wasted on an SSD.


Many servers deploy dual drives to separate the OS from data storage. The SSD improves server responsiveness for users connecting and sending requests. The high capacity HDD has plenty of space for storing databases, virtual machine images, log files, etc.


For laptops that have room for just one traditional drive, adding an M.2 SSD allows for a dual drive setup. The M.2 SSD houses the OS for fast boots and resumes while the 2.5″ HDD stores all your files. No more waiting on a sluggish 5400 RPM laptop hard drive.

Factors to Consider

If you’re thinking about moving from a single drive to a dual drive setup, here are some factors to consider first:

Your Performance Needs

Consider the performance requirements of the applications and workloads you plan to use most frequently. For general use, an SSD paired with an HDD is typically sufficient. For demanding creative work, RAID 0 may be required.

Drive Interface

This includes connections like SATA, PCIe, and M.2. The interface can impact maximum speeds so it’s ideal to match drives of the same interface when configuring RAID or a caching SSD. M.2 NVMe drives offer the fastest interface available.

Drive Format

Make sure to choose drives that use the same format. For Windows PCs that’s typically NTFS. For Macs it’s ideal to stick with HFS+ or APFS formatted drives. Mixing formats can introduce headaches.

Your Capacity Requirements

Add up the capacity required for apps/OS, current files, and expected growth. For general use 1TB total often suffices, but gamers and creative pros may need multiple TB. Plan ahead so you don’t end up short on space.

RAID Controller

Using motherboard RAID controllers is convenient, but a dedicated hardware RAID card will provide better performance and options like battery-backup caching. This is most applicable to servers housing mission critical data.

Dual Drive Cost Considerations

One decision point when choosing a dual drive setup is determining the ideal price point for each of the drives. Here are some typical options:

Modest SSD + High Capacity HDD

For general home use, a 250-500GB SATA SSD paired with a 2TB or larger HDD gets the job done at a reasonable price point. Expect to pay around $100-150 total for this combo.

High-End SSD + Medium HDD

Enthusiasts may opt for a 500GB-1TB M.2 NVMe SSD with a 2TB HDD. Expect to pay around $300+ for these high-end SSDs, with the HDD adding $50-100.

Dual Enterprise HDDs

For servers aiming for capacity over speed, dual 10TB+ enterprise HDDs can provide abundant redundant storage at around $300-500 each.

Dual High-End SSDs

At the cutting edge, dual 1TB+ M.2 NVMe SSDs in RAID 0 can offer incredible speed for media editing and design workloads. Expect to pay $500+ per SSD.

Performance Comparison: Single vs Dual Drive

For quantitative comparison, here’s a benchmarks of common single vs dual drive configurations:

Configuration Sequential Read Sequential Write
250GB SATA SSD 550 MB/s 520 MB/s
2TB 5400 RPM HDD 100 MB/s 80 MB/s
250GB SATA SSD + 2TB HDD 550 MB/s 520 MB/s
500GB NVMe SSD (RAID 0) 6,500 MB/s 5,000 MB/s

As you can see, combining an SSD and HDD provides speed near that of the SSD alone, while also adding abundant slow storage. And RAID 0 can provide exponentially greater speeds, ideal for performance intensive workflows.

How to Configure Dual Drives

The process for setting up a dual drive system will vary depending on your goals:


1. Install SSD and HDD in free drive bays.
2. Attach power and data cables.
3. Boot into BIOS and make sure both are detected.
4. During OS installation, select the SSD as the boot drive.
5. Once in the OS, format the HDD and begin transferring files.


1. Install two matched drives in free bays.
2. Attach cables and boot into BIOS.
3. Enable RAID mode in the BIOS
4. Select the drives and choose “RAID 0”
5. Initialize the RAID array and install OS.

SSD Cache

1. Install HDD in a drive bay.
2. Install SSD in an available M.2 slot.
3. Boot into BIOS and enable M.2 SSD caching.
4. Set the caching mode (write-through, write-back, etc)
5. Boot into OS and utilize drives as normal.

Be sure to back up any important data first! initializing and configuring RAID or cache settings will wipe existing drive contents.


While a single drive can be sufficient for many users, utilizing a dual drive setup provides a compelling combination of speed, capacity, reliability, and flexibility.

SSD + HDD gives you the best of both worlds, with fast boots and app launches combined with abundant storage for all your files and data. Creative pros can leverage RAID 0 for enhanced performance during resource intensive work. And everyone benefits from the redundancy of keeping the OS isolated from user data.

With SSD prices continuing to drop and high capacity HDDs getting cheaper, dual drive systems are a cost-effective way to amplify your computer’s capabilities. If you feel the constraints of a single drive, it may be time consider making the upgrade.