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Edits made to hardware folder (#19536)

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* fix: update general hardware info

* fix: remove typos and update hard-drives

* fix: remove redundant sentence in GPU
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Sayyed Raza
2018-10-22 18:39:10 -04:00
committed by Tracey Bushman
parent 02206a2123
commit 894e67cfd6
3 changed files with 4 additions and 5 deletions
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guide/english/computer-hardware/gpu/index.md
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@ -13,7 +13,6 @@ The GPU was originally used mainly for 3D game rendering to improve your resolut
There are two major brands producing GPUs: NVidia and AMD. They are often referred as the "green team" and "red team" which indicate the major color of their logo.
Notable makers of GPU's include: Nvidia and AMD/ATI.
## Origin of GPU

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guide/english/computer-hardware/hard-drives/index.md
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@ -10,13 +10,13 @@ Traditional hard disks use magnetic needles and rotating magnetized platters to
Hard drives come in various storage capacities, with some even storing 10TB (10 trillion bytes). Typical computers come with 256GB (256 million bytes) to 1TB of storage space. Laptops usually use Solid State Drives (SSDs) because they are faster, lighter, and contain no moving parts, making them less likely to fail due to impact. For the same amount of storage, SSDs are generally more expensive than hard drives. Recently, some SSDs have been released that interface with the motherboard through the PCIe (PCI Express) bus slot using a system called NVMe. These SSDs have proven to be even faster at read/write times than traditional SATA SSDs.
Magnetic heads are responsible for reading and writing data, which is physically stored on a set of magnetically coated discs stacked above one another--referred to as a platter. The heads are located at the end of an armature. The interior discs of the platter have two heads on a single arm. This allows data to be accessed from both the discs, beneath and above the arm. The top and bottom discs of the platter only have one head at the end of an arm. On the opposite end of the arm is an actuator. It provides movement of the arm to travel from the center of the platter, the spindle, to the outermost regions of the platter. The amount of time it takes to place the head in the correct concentric location is referred to as the seek time. Once the head is in the correct concentric spatial location more time is spent waiting for the disc to rotate such that the sector with the requested data is beneath the head. This amount of time is referred to as latency.
Magnetic heads are responsible for reading and writing data, which is physically stored on a set of magnetically coated discs stacked above one another, referred to as a platter. The heads are located at the end of an armature. The interior discs of the platter have two heads on a single arm. This allows data to be accessed from both the discs, beneath and above the arm. The top and bottom discs of the platter only have one head at the end of an arm. On the opposite end of the arm is an actuator. It provides movement of the arm to travel from the center of the platter, the spindle, to the outermost regions of the platter. The amount of time it takes to place the head in the correct concentric location is referred to as the seek time. Once the head is in the correct concentric spatial location more time is spent waiting for the disc to rotate such that the sector with the requested data is beneath the head. This amount of time is referred to as latency.
The heads are positioned only a few nanometers away from the rotating discs. The heads are said to "fly" above the platter and as such the distance between head and platter is referred to as the 'flying height'. The heads are designed to never touch the locations of the platters that store data and are magnetically coated. Should the head 'touch down' on a platter, both the head and sectors of the platters may be destroyed resulting in data loss (hence the phrase "a hard drive crash" or "head crash").
Hard drives retrieve and store data from applications at the request of the CPU. This is referred to as input/output operations--IO for short. When a running program requires a certain piece of data, the CPU dispatches an instruction for the data to be fetched from the hard drive. Reading this piece of data is an input operation (from the CPU's perspective). The program may then perform a computation which changes the data and the results need to be stored back out to the hard drive. The CPU requests the data be written back out to the drive. This would be an example of an output operation (again, from the CPU's perspective).
Hard drive performance is measured primarily by two key metrics 1) response time, which is how long it takes a read or write operation to complete and 2) IOPS which is an acronym for 'Input / Output Operations per Second'. As the name would suggest, IOPS is a measurement of the maximum IO operations in one second. The primary factor in achieving maximum IOPS at the lowest response time is the hard drive's rotational speed measured in revolutions per minute (RPM). Common rotational speeds are 5,400 RPM, 7,200 RPM, 10,000 RPM and 15,000 RPM (commonly notated as 5.4K, 7.2K, 10K and 15K). Hard drives with higher rotational rates RPM's) will have more platter real estate pass beneath the heads for IO operations (reads and writes). Hard drives with lower RPM rotational rates will have much higher mechanical latencies, as less real estate passes beneath the heads.
Hard drive performance is measured primarily by two key metrics 1) response time, which is how long it takes a read or write operation to complete and 2) IOPS which is an acronym for 'Input / Output Operations per Second'. As the name would suggest, IOPS is a measurement of the maximum IO operations in one second. The primary factor in achieving maximum IOPS at the lowest response time is the hard drive's rotational speed measured in revolutions per minute (RPM). Common rotational speeds are 5,400 RPM, 7,200 RPM, 10,000 RPM and 15,000 RPM (commonly notated as 5.4K, 7.2K, 10K and 15K). Hard drives with higher rotational rates (RPM's) will have more platter real estate pass beneath the heads for IO operations (reads and writes). Hard drives with lower RPM rotational rates will have much higher mechanical latencies, as less real estate passes beneath the heads.
One simple tool for measuring hard drive performance metrics is called IOMeter (see link below). The program is very lightweight and easy to install. Once it is up and running, several different variations of workloads can be run to simulate data reads & writes to the disk. This data is analyzed and outputs metrics for read/write times, IOPS, as well as other useful metrics. Tests can be saved for consistent checks, and the data can easily be parsed in a table or graph form.
@ -24,7 +24,7 @@ Hard drives tend to be categorized by use case (capacity or performance). Home P
Computers store data and files on hard drives for later use. Because hard drives have moving parts, it takes much longer to read a file from a hard drive than from RAM or cache memory on the CPU. You can think of a hard drive as a filing cabinet: a place to store things that we aren't using right now, but need later. You don't have enough room on your desk for all your papers, so you store things you aren't using right now in the filing cabinet. A computer does just this. It keeps files it is using right now in RAM, and files it might need later stay on the hard drive. Though RAM has access and response times that are two orders of magnitude faster when compared to hard drives, their typical capacity is 1-2 orders of magnitude less that a typical hard drive. You can fit reams of paper in the filing cabinet, but only a few on your desk.
Data stored in RAM is said to be fleeting whereas data written out to a hard drive is persistent. Meaning if the power suddenly goes out, any data that was in RAM is lost and will not be there after power is restored and the computer is booted back up. However data that was written to the hard drive will be there when power is restored. For this reason, modern operating systems and applications will periodically write session and application related data that's currently in RAM out to the hard drive. This way if the power goes out, only 10 minutes of data entered in a newly created spreadsheet that was being worked on for 3 hours preceding the power outage and not yet saved to the hard drive. These files are usually denoted with a tilde~ and can be found in a temporary or temp directory or possibly located in a 'blind directory' whose contents are referred to as hidden files.
Data stored in RAM is said to be fleeting whereas data written out to a hard drive is persistent. Meaning if the power suddenly goes out, any data that was in RAM is lost and will not be there after power is restored and the computer is booted back up. However data that was written to the hard drive will be there when power is restored. For this reason, modern operating systems and applications will periodically write session and application related data that's currently in RAM out to the hard drive. This way if the power goes out, only 10 minutes of data entered in a newly created spreadsheet that was being worked on for 3 hours preceding the power outage and not yet saved to the hard drive will be lost. These files are usually denoted with a tilde, ~ , and can be found in a temporary or temp directory or possibly located in a 'blind directory' whose contents are referred to as hidden files.
## Solid State Drives (SSD)
Solid State Drives uses integrated circuits to store data. Therefore, an SSD has no moving parts like the HDD. This makes them less prone to physical shocks, run silently, and have faster read/write times thanks to not needing to locate the data physically.

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guide/english/computer-hardware/index.md
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@ -13,7 +13,7 @@ A Central Processing Unit (CPU) is the electronic circuitry within a computer th
![Intel Core i5 - Front](https://upload.wikimedia.org/wikipedia/commons/thumb/8/83/Intel_i5-2500.jpg/247px-Intel_i5-2500.jpg) ![Intel Core i5 - Back](https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Intel_i5-3330%2C_bottom.jpg/240px-Intel_i5-3330%2C_bottom.jpg)
### Expansion Cards (eg. GPU)
A graphics processing unit (GPU) is a specialized electronic circuit designed to rapidly manipulate and alter memory to accelerate the creation of images in a frame buffer intended for output to a display device.
An expansion card is an embedded circuit card that can be added to the motherboard to augument a computer's capability. It can either add capabilities, ex allow for a new type of I/O port, or upgrade existing ones, ex. faster ethernet connection. The most common type of expansion card is a GPU, or a graphical processing unit.
![Nvidia Titan XP](https://cdn.arstechnica.net/wp-content/uploads/2017/04/nvidia-titan-x.jpg)