Autonomía digital y tecnológica

Código e ideas para una internet distribuida

Linkoteca. disco duro

MBR does have its limitations. For starters, MBR only works with disks up to 2 TB in size. MBR also only supports up to four primary partitions—if you want more, you have to make one of your primary partitions an “extended partition” and create logical partitions inside it. This is a silly little hack and shouldn’t be necessary.

GPT stands for GUID Partition Table. It’s a new standard that’s gradually replacing MBR. It’s associated with UEFI, which replaces the clunky old BIOS with something more modern. GPT, in turn, replaces the clunky old MBR partitioning system with something more modern. It’s called GUID Partition Table because every partition on your drive has a “globally unique identifier,” or GUID—a random string so long that every GPT partition on earth likely has its own unique identifier.

GPT doesn’t suffer from MBR’s limits. GPT-based drives can be much larger, with size limits dependent on the operating system and its file systems. GPT also allows for a nearly unlimited number of partitions.

On an MBR disk, the partitioning and boot data is stored in one place. If this data is overwritten or corrupted, you’re in trouble. In contrast, GPT stores multiple copies of this data across the disk, so it’s much more robust and can recover if the data is corrupted.

GPT also stores cyclic redundancy check (CRC) values to check that its data is intact. If the data is corrupted, GPT can notice the problem and attempt to recover the damaged data from another location on the disk. MBR had no way of knowing if its data was corrupted—you’d only see there was a problem when the boot process failed or your drive’s partitions vanished.

An SSD does functionally everything a hard drive does, but data is instead stored on interconnected flash-memory chips that retain the data even when there’s no power present. These flash chips are of a different type than the kind used in USB thumb drives, and are typically faster and more reliable.

The PC hard drive form factor standardized at 5.25 inches in the early 1980s, with the now-familiar 3.5-inch desktop-class and 2.5-inch notebook-class drives coming soon thereafter. The internal cable interface has changed from serial to IDE (now frequently called Parallel ATA, or PATA) to SCSI to Serial ATA (SATA)

An SSD-equipped PC will boot in less than a minute, and often in just seconds. A hard drive requires time to speed up to operating specs, and it will continue to be slower than an SSD during normal use.

Because of their rotary recording surfaces, hard drives work best with larger files that are laid down in contiguous blocks. That way, the drive head can start and end its read in one continuous motion. When hard drives start to fill up, bits of large files end up scattered around the disk platter, causing the drive to suffer from what’s called fragmentation. While read/write algorithms have improved to the point that the effect is minimized, hard drives can still become fragmented to the point of affecting performance. SSDs can’t, however, because the lack of a physical read head means data can be stored anywhere without penalty. Thus, SSDs are inherently faster.

An SSD has no moving parts, so it is more likely to keep your data safe in the event you drop your laptop bag or your system gets shaken while it’s operating.

SSDs make no noise at all; they’re non-mechanical.

An SSD doesn’t have to expend electricity spinning up a platter from a standstill. Consequently, none of the energy consumed by the SSD is wasted as friction or noise, rendering them more efficient.

While it is true that SSDs wear out over time (each cell in a flash-memory bank can be written to and erased a limited number of times), thanks to TRIM command technology that dynamically optimizes these read/write cycles, you’re more likely to discard the system for obsolescence (after six years or so) before you start running into read/write errors with an SSD.