Operating Systems

There are several operating systems for both servers and desktops. In some cases the difference between a server system and its desktop counterpart (if any) is small; in other cases very larger. Thus it is difficult to be concise. Very broadly, the differences are:

1. Server OSes usually remove features that aren't needed on a system that isn't use interactively, consume extra resources, or impair system reliability. For example:
   • Windows Server 2003 and 2008 disable hardware graphics acceleration.
   • Most Linux server-oriented distributions lack any graphical interface at all, and use only a command line.
2. Server OSes in turn bundle applications that aren't useful to the majority of desktop users, such as web, email, and domain name servers.
3. Server OSes often support more powerful hardware than desktop systems, especially in the case of Windows. Windows XP / Vista limit the number of physical processors and amount of RAM that is usable. Server editions increase these limits, with the most expensive versions supporting the most processors and the most RAM.
4. Server OSes are usually optimized differently, such as for allowing more applications to run simultaneously or allocating more resources to background processes than user processes.

• Cheap labour force
• Somewhat lower rules on waste management
• Lower workers rules, e.g they may not have to have as many breaks compared to if they were operating in MEDC's

• If they're found out by the press/society, it could ruin their social integrity and name of their company
• Could possibly have to ship their produce further to get them to LEDC's

Windows XP uses much few resources than Windows 7.

Windows 7 System Requirements:

• 1 gigahertz (GHz) or faster 32-bit (x86) or 64-bit (x64) processor

• 1 gigabyte (GB) RAM (32-bit) or 2 GB RAM (64-bit)

• 16 GB available hard disk space (32-bit) or 20 GB (64-bit)

• DirectX 9 graphics device with WDDM 1.0 or higher driver

Windows XP System Requirements:

• Pentium 233-megahertz (MHz) processor or faster (300 MHz is recommended)
• At least 64 megabytes (MB) of RAM (128 MB is recommended)
• At least 1.5 gigabytes (GB) of available space on the hard disk
• Video adapter and monitor with Super VGA (800 x 600)or higher resolution

The unique requirements of real-time operating systems can be characterized by five general areas and are discussed below:

Determinism: Determinism is concerned with the time it takes, delay time, for an operating system to acknowledge an interrupt. An operating system is deterministic to the extent in that the performance of operations are at fixed, predetermined times or within predetermined time intervals.

Responsiveness: Responsiveness is concerned with the time an operating system services an interrupt once an acknowledgement is received. There are three aspects of responsiveness which include the following:

1) The time required to initially handle the interrupt and being execution of the interrupt service routine (ISR).

2) The time required to perform the ISR which is generally dependent on the hardware platform.

3) Since an interrupt can be affected by the arrival of another interrupt the nesting effect is of interest.

User control: In real-time operating systems, the users have find-grained control over scheduling task priority. The user must have a complete understanding between hard and soft tasks and to specify relative priorities within each class. Several characteristics may be available for the user to specify in these systems, such as, the use of paging or process swapping, what processes must always be resident in main memory, what disk transfer algorithms are to be used, the various processes' priority bands, etc.

Reliability: In comparison to non-real-time operating systems, reliability of real-time operating systems is far more important since the system is responding to and controlling events in real time. Performance degradation or loss thereof may have catastrophic consequences, ranging from financial loss to major equipment damage and even loss of life. Non-real-time systems include, but not limited to, transient failure and processor failure in a multiprocessor system.

Fail-soft operation: The characterization of Fail-soft operation refers to the ability of a system to fail in such a way as to preserve as much capability and data as possible. In a real-time system, the system attempts to correct the problem or minimize its effects while continuing to run. Stability is an important aspect of fail-soft operation, and an example of stability is provided for clarity purposes. In cases where it is impossible to meet all task deadlines, the real-time system remains stable while meeting the most critical, highest-priority tasks even if some of the less critical task deadlines are not met. The following features are usually included in real-time operation systems: fast process or thread switch, small size, ability to respond to external interrupts quickly, multitasking with interprocess communication tools such as semaphores, signals, and events, use of special sequential files that can accumulate date at a safe rate, preemptive scheduling based on priority, minimization of intervals during which interrupts are disabled, primitives to delay tasks for a fixed amount of time and to pause/resume tasks, special alarms and time-outs, etc.