Description: This article contains some of the most frequently asked questions about Solid State Drives and Hard Disk Drives from Fall 2019.

Q: What does SSD stand for?
A: SSD stands for Solid State Drive.

Q: What does HDD stand for?
A: HDD stands for Hard Disk Drive.

Q: What is the difference between an SSD and an HDD?
A: Solid State drives use flash storage like a USB flash drive. They have no moving parts and operate much quicker than regular hard drives. HDDs use a circular disc that spins any time you save or open a program and a read write head.

Q: Why doesn’t everyone use an SSD?
A: SSDs are typically more expensive than HDDs for the same storage space.

Q: What is an M.2 SSD?
A: M.2 is a newer form factor that allows the SSD to plug in to the motherboard directly without any cables. There are currently two types: NVME M.2 and SATA M.2 drives.

Q: Do M.2 drives have different sizes?
A: M.2 drives do have different form factors. Just like hard drives come in 2.5 inch or 3.5 inch sizes, M.2 drives have a number in the name that will designate the size of the card, usually 2240, 2260, and 2280. The larger the number means the drive is longer. Many motherboards support multiple sizes.

Q: What is the difference between NVME M.2 and SATA M.2?
A: NVME drives utilize the PCIe bus of a computer and provide faster data transfer speeds than standard SATA connections. SATA III speeds have a max around 600 MB/s and NVME speeds can reach upwards of 3,500 MB/s.

Q: Do hard drives have different speeds as well?
A: Yes, Hard Disk Drives use RPMs, or Revolutions per Minute, to determine the speed of the drive. The most common speeds for hard drives are 5400 RPM and 7200 RPM. 7200RPM drives will typically max at 110-120MB/s speeds under good conditions but will usually operate slower than that.

Q: What is Ultra M.2?
A: Ultra M.2, Hyper M.2, Turbo M.2 are all various terms used by manufacturers to represent faster M.2 slots. Normally it just means they are not using the standard M.2 PCIe x2 speeds. They still support the same M.2 drives as the regular slots.

Q: Why are there different keys for M.2 drives?
A: M.2 drives can be configured as either B, M, or B and M keys. Like how RAM has different types of slots, M.2 slots need to be compatible with the key of the M.2 drive. This is to prevent the incorrect modules from being plugged in to the computer.

Q: Why do computers include both an SSD and HDD?
A: Computers that offer both an SSD and an HDD provide the best of both worlds in terms of speed and storage space. The SSD is typically used as the boot drive to allow faster boots and startup time for applications, while the HDD can be used to store documents and other data because it is larger than the SSD.

Q: Why is my new hard drive not detected?
A: New drives need to be formatted to show up in the operating system. You can format a drive in Windows using Disk Management, or Disk Utility if using a Mac. HDDs and SSDs that plug into SATA ports may not be detected if a SATA M.2 drive is installed. Depending on the manufacturer of the motherboard one or more SATA ports may be disabled.

Q: What is GPT?
A: GPT stands for GUID Partition Table, which is a newer standard for organizing information on drives. This is typically used in conjunction with UEFI which is a newer BIOS format. More information can be found at our support article https://www.microcenter.com/tech_center/article/4266/what-is-gpt.

Q: What is MBR?
A: MBR stands for Master Boot Record, which is the older standard for organizing information on drives. Due to the age of this standard it limits drives to only about 2TB of storage space. More information can be found at our support article https://www.microcenter.com/tech_center/article/4267/what-is-mbr.

Q: Which option should I use when initializing and formatting a new drive?
A: GPT is the recommended option because it works on hard drives that are larger than 2TB.

Q: Why doesn’t the drive show the full space I purchased?
A: This is caused by manufacturers and Windows using different ways to calculate the space on the drive. More information can be found at our support article https://www.microcenter.com/tech_center/article/7998/why-windows-reports-a-smaller-drive-size-than-expected.