Serial port requiring programs to refer to them by hardware address. Unix-like operating systems usually label the serial port devices /dev/tty*. "TTY" is a common trademark-free abbreviation for "teletype", a device commonly attached to early computers' serial ports, and * represents a string identifying the specific port; the syntax of that string depends on the operating system and the device. On Linux, 8250/16550 UART hardware serial ports are named /dev/ttyS*, USB adapters appear as /dev/ttyUSB* and various types of virtual serial ports do not necessarily have names starting with tty. The DOS and Windows environments refer to serial ports as COM ports:
Embarrassingly parallel are thus well suited to large, Internet-based distributed platforms such as BOINC, and do not suffer from parallel slowdown. The opposite of embarrassingly parallel problems are inherently serial problems, which cannot be parallelized at all. A common example of an embarrassingly parallel problem is 3D video rendering handled by a graphics processing unit, where each frame (forward method) or pixel (ray tracing method) can be handled with no interdependency. Password cracking is another embarrassingly parallel task that is easily distributed on central processing units, CPU cores, or clusters. "Embarrassingly" is used here in the same sense as in the phrase