How Many Hard Drives Can a PC Have?

The number of hard drives a PC can have depends upon two factors. Firstly, it depends upon the type of hard drive you wish to install i.e Hard Disk Drive, or SSD. Secondly, it depends upon how much expansion capability your motherboard has i.e ports and slots.

As such, there is no maximum number of hard drives a PC can have. It all depends upon slot availability.

Hard disk drives require SATA slots and SSDs require SATA or M.2 slot depending upon what type of SSD you have.

A typical motherboard has about 4-8 SATA ports and 1-2 M.2 slots. Meaning you can have about 4-8 SATA hard drives and 1-2 SSDs conforming to the M.2 form factor. So this gives a combined total of about 5-10 hard drives.

But in addition to that, you can also increase the number of SATA or M.2 slots using PCIe slot expansion cards. These are specialized cards that plug into the PCIe slots on your motherboard. Therefore, depending upon how many PCIe slots a motherboard has, a PC can have far more than 6-8 hard drives if using the port expansion cards.

In the following text I will talk in detail about how many hard drives can a PC have and also how to add more.

SATA and PCIe Hard Drives

Before we delve into the question of how many hard drives can a PC have, let us first discuss in brief the type of hard drives you can install on your PC. 

There are basically two interfaces that you can use to add hard drives:

  • SATA: The slower interface
  • PCIe: Much Faster interface

SATA Drives and Ports

SATA hard drives connect to the SATA ports on your motherboard:

Which is Faster SATA or PCIe
SATA Ports

There are three types of SATA hard drives:

  1. Hard Disk drives
  2. 2.5″ SATA SSD drives
  3. M.2 SATA SSD

The Hard Disk drives are your typical large 3.5″ and 2.5″ drives with magnetic plates for storage. These can reach a maximum transfer speeds of about 200 MB/s at best.

Can You Use a Laptop Hard Drive in a Desktop hard disk
A 3.5″ SATA Hard Disk Drive. AKA Desktop HDD.

The 2.5″ SATA SSD drives are solid state drives that connect to the SATA port on your motherboard. These can reach sustained speeds of about 550 MB/s max.

SATA SSD Connectors power data
2.5″ SATA SSD – SATA Drives require SATA DATA and SATA Power Cable

Each SATA hard drive connects to an individual SATA port on your motherboard. Meaning you cannot connect two SATA drives to a single SATA port on your motherboard.

The third type of SATA hard drive is the M.2 SATA SSD. These SSDs have the M.2 form factor but utilize the SATA interface. They also reach a maximum of 550 MB/s transfer speeds.

M.2 SATA SSDs plug into an M.2 slot. 

Samsung Evo 860 SATA SSD m.2
Samsung Evo 860 SATA SSD with M.2 form factor

PCIe Based Hard Drives

The second interface used for connecting hard drives is the much faster PCIe interface.

There is only one type of commercial hard drive that uses the PCIe interface, the PCIe NVMe SSDs.

PCIe NVMe SSDs use the M.2 form factor. However, compared to the M.2 SATA SSDs, they are multiple folds faster. A Gen 3 NVMe SSD can reach speeds of 3500 MB/s second. A Gen 4 NVMe SSD can reach speeds of about 6500-7000 MB/s!

samsung 980 pro
Samsung 980 Pro. M.2 PCIe 4.0 NVMe SSD

These drives CANNOT be inserted directly into the PCIe slots. They require M.2 slots that conform to the right PCIe version i.e version 3.0 for Gen 3 SSDs and version 4.0 for Gen 4 SSDs.

Read in Detail: What is Difference Between SATA and SSD and HDD and NVMe?

The important point to note from this section is that when answering the question “how many hard drives can a PC have?” you HAVE to take into consideration what type of hard drives you wish to add. 

So How Many Hard Drives Can a PC Have?

Again that depends upon whether the hard drive in question is Hard Disk Drives, 2.5″ SSDs or M.2 SSD.

Typically, the exact answer to the question depends upon what motherboard you have.

A budget motherboard with an mATX form factor has about 4 x SATA ports and 1 x M.2 slot (i.e ASUS H610M S2 DDR4). Hence this PC can have 5 x hard drives, i.e. 4 x SATA HDD/SSD and 1 x M.2 SSD.

A mid range motherboard with mATX or ATX form factor has about 6 x SATA Ports and 2 x M.2 slots (i.e ASUS TUF Gaming B550-PLUS). Hence this PC can have 8 x hard drives. 

A high end motherboard with ATX form factor has about 8 x SATA ports and 2-4 M.2 slots (i.e ASUS TUF Gaming X570-Plus). Hence, this PC can have upto 12 x hard drives.

The best way to determine how many hard drives your PC can have is through its specsheet.

Take for instance, the storage specsheet for the ASUS TuF Gaming X570-Plus below:

How Many Hard Drives Can a PC Have
ASUS Tuf Gaming X570 Gaming Plus Storage Specs

Reading through this specsheet, you can see that this motherboard offer 8 x SATA Ports and two M.2 slots – one powered from the CPU and the other coming from the AMD X570 Chipset. 

Note the caveat that the first M.2 slot will only support Gen 4 NVMe SSDs IF the CPU you have is from the Ryzen 5000 or the 3000 non-G series, otherwise it will conform to the PCIe 3.0 version and will support gen 3 NVMe SSDs. 

In addition to that both the M.2 slots support both SATA and NVMe M.2 SSDs.

As such, we can conclude that the motherboard above can support

  • 8 x SATA hard drives connecting to the SATA ports
  • 2 x M.2 hard drives

You can also figure out the number of hard drives your PC can have by manually counting the number of SATA ports and the M.2 slots on your motherboard yourself.

However, do note that sometimes a SATA port shares bandwidth with an M.2 slot. Hence populating one disables the other. This can only be figured out through the specsheet.

It should be noted that optical drives, such as DVD drives, also use the SATA interface and connect to the SATA port. Hence, adding an optical drive to your PC will reduce the number of SATA hard drive you can have by one.

You Can Increase the Number of SATA and M.2 Slots for Adding More Hard Drives 

If you have run out of SATA ports for your hard disk drives or M.2 slots for your SSDs, then fortunately, you can add more using the PCIe expansion slots.

What are PCIe Slots?

PCIe slots are the long rail-like slots that all commercial motherboards have. These are used to add more capability to your PC. For instance, you can add an advanced graphics card, a specialized sound card, WiFi card etc.

does it matter which pcie slot I use w
PCIe Slots for adding expansion cards. Note that the bottom x16 slot actually only has 4 lanes. You can figure this out by reading the specsheet of the motherboard.

In order to add more hard drives to your PC, you can use these PCIe slots to install port expansion cards. 

There are different sizes of the PCIe slots differentiated by the number of PCIe lanes they have. The higher the number of PCIe lanes, the larger the expansion card a slot can be occupied with.

So basically, while a small x1 slot with one lane can be used to add an expansion card with 2-4 additional SATA ports. An x4 slot can be used to add 10 or more SATA ports to your PC.

SATA and M.2 Expansion Cards

The following is a typical SATA port expansion card. This is a cheap and an effective method to increase the number of SATA ports you have.

As you can see, it has an x1 connector and thus fits into an x1 slot. It provides an additional 4 x SATA ports to your PC which you can then use to add four additional SATA hard drives.

PCIe SATA expansion card x1
PCIe SATA expansion card. Plugs into an  x1 PCIe slot and provides four SATA slots.

Read in detail: How to add more SATA Ports to motherboard? 

Similarly, you have M.2 slot expansion card. Note that while a SATA M.2 SSD can work using a single PCIe lane, an NVMe SSDs requires four PCIe lanes.

Hence an extra M.2 slot expansion card for NVMe SSDs requires a expansion card with an x4 connector and requires at least an x4 PCIe slot. 

Expansion Card for one M.2 NVMe Slot. Source: Rivo

Also Read in Detail: How to Add More M.2 SSD Slots? 

Final Words

All in all, the answer to the question how many hard drives can a PC have depends upon what motherboard you have. To be precise, it is determined by the number of SATA and the M.2 slots you have on your motherboard.

Typically you can have about 4-8 SATA ports and about 2 x M.2 slots on an average motherboard. A budget motherboard, has 4 SATA ports and 1 x M.2 slot whereas high end motherboard can feature 8 SATA ports and 2-4 M.2 slots. 

Each SATA HDD and SSD and NVMe SSD requires an individual slot. In other words, one SATA or M.2 slot on a motherboard cannot be used to add two drives.

You can add more SATA and M.2 slots to your motherboard using the PCIe slots for adding slot expansion cards.

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Author:

Atif Qazi
Atif Qazi is the founder of PCGuide101. He is a digital nomad who loves everything PC. He is a PC builder, tech enthusiast, engineer, and a lover of single player lore-rich RPG games.

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