A hard drive is a key component of a computer that provides non-volatile data storage. It consists of one or more spinning magnetic disks called platters that can store data. The hard drive reads and writes data to these platters using a read/write head that moves quickly over the surface of the disk (https://www.crucial.com/articles/pc-builders/what-is-a-hard-drive). Hard drives allow computers to store large amounts of data, including the operating system, programs, and user files. Without a hard drive, a computer typically cannot boot or function properly once powered off, since the volatile system memory (RAM) is cleared on shutdown. The capacity of modern hard drives ranges from hundreds of gigabytes to tens of terabytes, allowing computers to permanently store many applications, media files, and documents.
Boot Options Without a Hard Drive
There are a few ways to boot a PC without an internal hard drive installed. The most common options are booting from external media like a USB drive or bootable CD, configuring network boot, or using a RAM disk.
To boot from external media, you first need to access the BIOS and configure it to boot from USB or CD first in the boot order priority. Most modern BIOS systems allow configuring a boot order to try external sources before the internal hard drive. Once this is set, you can insert a USB drive or CD with a bootable operating system installed and power on the computer to load the OS from the external media (Source).
Network booting works by configuring the BIOS to boot over the network instead of a local drive. This requires a network boot server like PXE to host the boot files. The client computer will load the OS over the network without needing any local storage (Source).
A RAM disk uses available system memory as a virtual boot drive. After configuring a section of RAM to act as a drive, boot files can be copied to it and the BIOS set to boot from the RAM disk instead of a physical hard drive.
Running Linux Without a Hard Drive
It is possible to run Linux without installing it to a hard drive by using a live Linux system on a CD or USB drive. Most major Linux distributions like Ubuntu, Linux Mint, and Fedora offer a “live” version that can boot directly from removable media without accessing the hard drive. This allows Linux to be run as a complete operating system for troubleshooting purposes or just to test out Linux without committing to an installation.
According to an AskUbuntu thread, Ubuntu’s live CD/DVD will work fine without a hard drive installed. The live system loads into RAM and runs directly from there rather than accessing the hard drive. However, any changes or files created during a live session will not be saved without additional configuration.
Some users in a Linux.org forum thread report successfully installing Linux distributions like Debian and Arch Linux to a live USB without a hard drive present. This requires manually configuring the Linux installer and kernel to treat the USB as its root filesystem. Performance is slower than running from a hard drive, but it shows Linux can function without local storage if configured properly.
Using Older Operating Systems
Older versions of Windows and Mac operating systems can run directly from floppy disks, CDs, or DVDs without requiring a hard drive installation. This was common before hard drives became standard. For example, Windows 95 and 98 can run from a bootable floppy disk containing the core operating system files. The computer would load Windows into RAM from the floppy disk or CD. However, performance is very limited without a hard drive since all applications and data must also be accessed from the slow removable media.
Likewise, classic versions of Mac OS prior to Mac OS X can be booted directly from floppy disks or CD-ROM discs, rather than being installed to a hard drive. This allows the retro Mac operating system experience without a hard drive. However, the system is read-only and limited until files can be copied or saved to a writable removable disc.
While booting from legacy media is possible with older systems, the capabilities are extremely constrained versus running from a hard drive. Storage space is very limited and performance is slow. This approach is mainly for nostalgia or troubleshooting purposes today.
Sources:
Working hard drive, but “Operating System Not Found”
Web-Based Computing
One way to use a PC without a hard drive is through web-based computing. This relies on internet connectivity and web apps rather than locally installed software. The prime example is Chromebooks, which run the Chrome OS operating system by Google. The Chrome OS is designed to work primarily with web apps like Google Docs, Gmail, YouTube, etc. Rather than storing apps and files locally, everything is stored in the cloud. This allows a Chromebook to function without needing a hard drive.
There are also options to access web apps from any computer using just a web browser. For example, Microsoft 365 provides web versions of Office apps like Word, Excel, PowerPoint, and more that can be used entirely in the browser. Google’s suite of web apps also works this way. So it’s possible to get by without a hard drive using just a web browser and internet connectivity.
The tradeoff is that web apps may have reduced functionality compared to full native apps, and they require persistent internet access. But for basic tasks like writing documents, email, spreadsheets, etc. web apps provide a feasible way forward without a hard drive.
RAM Disks
RAM disks utilize a portion of a computer’s RAM to emulate a physical hard drive for temporary data storage (Wikipedia). When enabled, RAM allocated to the virtual disk is no longer available to applications. The computer writes and reads data from the RAM disk as if it were a physical drive.
Since RAM disks utilize the much faster main memory, they can improve performance for disk-intensive operations like temporary file access, paging, caching, and more. However, the data is lost when the computer powers off. RAM disks are a type of volatile storage suitable for temporary usage. The space required must also be deducted from the total available RAM.
Common RAM disk software like SoftPerfect RAM Disk make it easy to create and manage virtual drives. Most operating systems support RAM disks, including Windows, Linux, and macOS. The maximum size is limited by the amount of spare RAM available.
External Storage Options
External storage drives provide a way to add storage space without having to install an internal hard drive. There are several types of external storage that can be used with a PC:
Flash drives – Also known as thumb drives or USB drives, flash drives plug into a USB port and provide portable storage. They come in capacities from 4GB to 1TB. Flash drives are small, convenient, and don’t require an external power source, but have slower transfer speeds than other options.[https://www.pcworld.com/article/406861/best-external-drives.html]
External hard disk drives (HDDs) – These drives use a spinning platter to store data, similar to an internal HDD. They connect via USB and require a separate power cable. External HDDs come in capacities from 500GB to 10TB+, offer faster speeds than flash drives, and provide a balance of affordability, capacity, and portability.[https://www.wired.com/story/best-portable-external-storage-drives/]
Network-attached storage (NAS) – NAS devices contain multiple internal drives and connect to the network, allowing all connected devices to access and share the storage. NAS units are more expensive but provide greater capacity, data redundancy, and centralized storage for multiple users and devices.
When choosing external storage, consider factors like portability needs, storage capacity, transfer speeds, and budget. With the right external drive, a PC can gain significant additional storage without an internal hard drive.
Cloud Storage
Cloud storage services allow users to store files and data on remote servers that can be accessed from any device via the internet. Popular consumer cloud storage services include Google Drive, Dropbox, OneDrive, Box, and iCloud. These services provide secure online file storage, backup, sharing, and file synchronization capabilities.
Cloud storage services are convenient for backing up important files and accessing them from any computer or mobile device. They provide protection against data loss by keeping copies of files on remote servers. Many services offer version history so users can restore previous versions of files if needed.
Cloud sync allows files to be updated and synchronized across multiple devices automatically. When a file is added or changed on one device, cloud sync will push that update to all other connected devices. This ensures the most up-to-date version of files are accessible on all synced devices.
Overall, cloud storage and sync services provide reliable offsite backup and easy accessibility for files on the go. They help safeguard against data loss while enabling seamless file sharing and access from anywhere.
Performance and Usage Considerations
Running a PC without a hard drive comes with some notable performance and usage limitations. Without a hard drive for storage, speed and capacity will be severely constrained.
Speed will be a major limitation. Since the PC will need to load the operating system and programs from external devices like USB drives or SD cards, speed will be limited to the transfer rate of those devices. This can mean apps, files and the OS will load much slower compared to having programs and data stored locally on a hard drive. According to Quora, running from external storage “[reduces] the overall system performance by 10-100x times depending on [the] type of drive.”
Capacity and storage will also be limited without an internal hard drive. For basic operations, only a few gigabytes may be necessary. However, for multimedia workflows, gaming, and running multiple programs, lack of local storage on a hard drive will quickly become a limitation. Any programs or files will need to fit on the external device being used for boot and storage. For most productive workflows, this capacity would be insufficient.
When a Hard Drive is Necessary
While it is technically possible to use a PC without a hard drive in certain circumstances, there are some cases where having a hard disk drive (HDD) is required for full functionality:
Installing an operating system – Most operating systems including Windows, Mac OS, and some Linux distributions need to be installed to a hard drive. While some operating systems like Ubuntu allow booting from external media, a HDD is required for installation and configuration.
Running demanding applications – Applications with large program files or that need to quickly access a lot of data will benefit greatly from having an internal hard drive for storage and the faster data transfer speeds.
Gaming – Most modern games have large storage requirements and need the faster data access of a HDD compared to external storage for optimal performance.
Offline access – A hard drive allows you to store files and programs locally so you can access them anytime without an internet connection. External and cloud storage require an internet connection.
Data security – Keeping sensitive files only on a local hard drive minimizes the risks associated with external drives and cloud storage which can be lost, stolen, or hacked.
Booting quickly – Using an HDD allows booting an operating system and loading programs much faster compared to booting from an external drive or cloud storage.
Cost savings – In the long run, an internal HDD provides more local storage for less money compared to external SSDs and cloud storage subscriptions.