Inside the plastic casing is a small printed circuit board, which has some power circuitry and a small number of surface-mounted integrated circuits (ICs).[citation needed] Typically, one of these ICs provides an interface between the USB connector and the onboard memory, while the other is the flash memory. Drives typically use the USB mass storage device class to communicate with the host.[28]
Unlike solid-state memory, hard drives are susceptible to damage by shock (e.g., a short fall) and vibration, have limitations on use at high altitude, and although they are shielded by their casings, they are vulnerable when exposed to strong magnetic fields. In terms of overall mass, hard drives are usually larger and heavier than flash drives; however, hard disks sometimes weigh less per unit of storage. Like flash drives, hard disks also suffer from file fragmentation, which can reduce access speed.
Capacity - More so than any other feature, capacity will drive the price of a flash drive up the most. So before you make a purchase, consider how much you’re willing to spend on a flash drive and weigh that against how much capacity you’ll likely need. A flash drive with 16GB can cost you as little as $10, while a 128GB one will run up to $60 or more.
“The solid state flash drive can theoretically achieve incredibly high transfer speeds, blurring the line between an external solid state drive and a flash drive,” our tester raved. He did note he was “unable to reach higher than half the listed read and write speeds.” However, he explained, “The Extreme Pro is still very fast compared to other USB 3.0 flash drives.” In the end, our tester recommended this flash drive “with the caveat that there's a good chance you won't see those 300+ MB/s transfer speeds.” He also added that for just a little more, you could invest in an external hard drive—if the ultra-compact form factor isn’t important in your buying decision.
Usually, such drives will be custom-stamped with a company's logo, as a form of advertising. The drive may be blank, or preloaded with graphics, documentation, web links, Flash animation or other multimedia, and free or demonstration software. Some preloaded drives are read-only, while others are configured with both read-only and user-writable segments. Such dual-partition drives are more expensive.[61]
A minority of flash drives support biometric fingerprinting to confirm the user's identity. As of mid-2005,[needs update] this was an expensive alternative to standard password protection offered on many new USB flash storage devices. Most fingerprint scanning drives rely upon the host operating system to validate the fingerprint via a software driver, often restricting the drive to Microsoft Windows computers. However, there are USB drives with fingerprint scanners which use controllers that allow access to protected data without any authentication.[70]
Particularly with the advent of USB, external hard disks have become widely available and inexpensive. External hard disk drives currently cost less per gigabyte than flash drives and are available in larger capacities. Some hard drives support alternative and faster interfaces than USB 2.0 (e.g., Thunderbolt, FireWire and eSATA). For consecutive sector writes and reads (for example, from an unfragmented file), most hard drives can provide a much higher sustained data rate than current NAND flash memory, though mechanical latencies seriously impact hard drive performance.
Macbooks require a USB Type-C device, which is where this swivel dual flash drive from Silicon Power comes in handy. It features a dual interface with USB Type-C and USB Type-A 3.0 ports on opposite ends of a compact device. The 360-degree swivel cap protects whichever connector is not in use and attaches easily to keychains. The C80 doesn’t require any special drivers or software to work; just plug it into the port and it is ready to go. But it has an optional file management app, which is a free and simple automatic file categorization that puts your work in the appropriate folders. Expect fast read and write speeds and 64 GB of storage to hold all your photos and files.