M.2 is the interface with which SSDs are connected to the motherboard and was first introduced in 2012 for SATA M.2 or mSATA. The M.2 interface connected data through either SATA, USB, and now PCIe lanes as opposed to the more common SATA connection to connect your HDDs and SSDs to the motherboard.
Because M.2 is able to connect your SSDs through the PCIe lanes it can take advantage of extremely high speeds as shown in our table above. With the addition of PCIe being a very important technology not just in data storage, newer generations are being developed to accelerate the throughput of this technology.
Modern motherboards have an M.2 slot built in. However, if your motherboard does not have M.2 or you want extra NVMe data storage you can purchase a PCIe to M.2 expansion card to add additional M.2 slots to your PC.
ATX motherboards have ample M.2 slots, but if you have a small form factor mATX motherboard (usually only sporting 1 M.2 slot), adding additional M.2 slots via a PCIe to M.2 expansion card is a great choice for adding high-speed data storage.
PCIe Generation
All PCIe Generations slots and M.2 slots are backward compatible, so there is no need to worry about purchasing the wrong expansion card or NVMe SSD. However, you might want to save a buck or two by buying the correct generation expansion card and NVMe SSD according to your motherboard and PCIe slot you plan to slot it in. Below are the speeds of potential M.2 SSDs depending on generation.
- PCIe Gen 3 M.2 SSDs deliver read speeds of about 3500 MB/s.
- PCIe Gen 4 M.2 SSDs deliver read speeds of about 7200 MB/s.
- PCIe Gen 5 M.2 SSDs (being tested right now) deliver read speeds of over 10000 MB/s!
PCIe Size and Lanes
PCIe size is an important factor because it determines whether or not you will actually have space for an expansion card. While there are a variety of sizes and combinations available, most users will only meet four basic sizes.
The number of direct connections available by a PCIe slot or card is represented by the size. M.2 NVMe SSDs require 4 PCIe lanes to operate.
- PCIe x1: a single PCIe lane does not support the M.2 interface]
- PCIe x4: M.2 NVMe SSDs occupy a single x4 slot]
- PCIe x8: expansion cards with 2 M.2 SSDs will need to use this slot]
- PCIe x16: your motherboard often has a primary x16 slot for GPUs and additional x16 slots. 16 PCIe lanes can support an expansion card with 4 additional M.2 NVMe SSDs. Be sure to have enough clearance and ample airflow for your hardworking GPU.
Lower PCIe lane cards can fit in higher slots; a PCIe x4 card and a PCIe x8 card can fit in a PCIe x16 slot, so there is no need to buy a PCIe x16 slot M.2 to PCIe expansion card if you don’t need all 4 M.2 slots.
Here are some great choices:
1. ASUS HYPER M.2 X16 GEN 4 Card M.2 to PCIe 4.0 Expansion Card – [PCIe 4.0 x16 to 4x M.2 Slots]
2. ASUS HYPER M.2 X16 Card V2 M.2 to PCIe 3.0 Expansion Card – [PCIe 3.0 x16 to 4x M.2 Slots]
3. SIIG SC-M20014-S1 M.2 NGFF SSD PCIe 3.0 Expansion Card Adapter – [PCIe 3.0 x4 to 1x M.2 Slots]
HDD vs. SSD vs. NVMe SSD
HDDs are the oldest form of data storage of the bunch and have the slowest read speeds at 150MB/s. SATA SSDs are a step up with speeds at about 500 MB/s. NVMe SSDs currently have speeds upwards of 3500 MB/s with more technology on the horizon.
Here’s a more comprehensive table of the comparisons
Hard Drive HDD | SATA SSD | NVMe SSD | |
---|---|---|---|
Interface | SATA III | SATA III | PCIe Gen 3, 4, & 5 (soon), NVMe |
Read Speed | up to 150 MB/s | up to 600 MB/s | PCIe Gen 3: 3500 MB/s
PCIe Gen 4: 6000 MB/s PCIe Gen 5: 10000 MB/s (projected) |
Mainstream Capacities | up to 18TBs | up to 8TB | up to 4TB |
Hot Swap Capable | Yes | Yes | Not M.2, Yes U.2 |
Form Factor | 3.5” Drive | 2.5” Drive or M.2 Slot | M.2 Slot or U.2 (enterprise) |