Week 2: RAM and Storage
This is a work in progress. My own views on RAM tend towards larger numbers, mostly because I tend to A) open lots of browser tabs and B) play games which can use a lot of RAM. Thus, my rule of thumb is that 16GB is more towards the minimum hardware RAM I would want installed on a modern system for general use, although I have found through virtual machine testing that 4GB of RAM (combined with at least two CPU threads) is needed for reasonable performance for Windows 10 for general use (basic web browsing, running most non-graphics intensive software). 16GB is what the testing from multiple YouTubers (for example: https://youtu.be/HnuNs_Nu46Q, https://duckduckgo.com/?q=is+8gb+enough&t=osx&iax=videos&ia=videos, PC Gamer: does-ram-matter-for-gaming, Linus Tech Tips: Does RAM speed REALLY matter?) found to be a practical minimum, although more is better if you run certain types of workloads or open a large number of browser tabs. In my own research, I've found that video cards with 4GB or more of VRAM are desirable to run modern games, although 8GB (or more!) is better still (Shadow of the Tomb Raider recommends 8GB of VRAM if available, https://store.steampowered.com/app/750920/Shadow_of_the_Tomb_Raider_Definitive_Edition/ ).
RAM is installed in slots on the motherboard, or soldered in in some cases, such as in many laptops and embedded systems. Soldered RAM lowers production costs at the expense of ease of repair and upgradability.
Hard Disk Drives work in much the same way as the obsolete floppy drives: they have spinning disks inside, and a read/write head which floats above or below on a cushion of air. They use magnetic fields to store data on the disk, which on hard drives is divided into sectors. Hard Drives (and optical drives, as well as SSDs) normally have a cache of RAM onboard to improve read a write performance. A hard drive head crash is quite undesirable and usually damages a hard drive. It occurs when dust or sudden movement causes the hard drive head to crash into the platter, which can scratch the platter and in some cases shatter it. This is why some laptop hard drives had motion sensors to attempt to detect a drop or fall and shut down the hard drive to try to prevent damage. This is also why new laptops almost exclusively use SSDs.
Solid State Drives or SSDs are used for similar purposes to conventional Hard Drives, but function quite differently. Like hard drives, they also normally have a RAM cache, although some cheap drives forgo it. Most SSDs use flash memory, although Intel's Optane SSDs use an alternative technology called 3D XPoint (which is also used for persistent RAM in DIMM slots, further blurring the lines between RAM and SSDs). Solid State Drives win when it comes to latency (Intel Optane SSDs tends to come out on top in this regard in particular) compared to Hard Drives or Optical Media, since SSDs have no seek time to find the location of data on a physical disk/disc. SSDs also usually beat Hard Drives on raw throughput, especially on read operations but also on most write operations, unless the SSD is using very cheap flash memory that has poor performance. Increasingly, SSDs are using PCIe as their interface rather than using SATA, due to the possibility of lower latency and much higher throughput with PCIe compared to SATA. SATA SSDs are still widely used, however, especially when cost per GB is the most important factor besides performance, since SATA SSDs tend to be cheaper than PCIe SSDs, as they can use lower performing flash memory without as much of an impact.
Tape drives used to be quite common, but are now mostly seen in enterprise backup systems and similar use cases (sometimes video recording still) now. Tape drives work by having a magnetic tape in a cartridge that moves past read and write heads at high speed. The main advantage of tape drives is the low cost per gigabyte, which is why storage solutions such as Amazon Glacier use them. They can also have surprisingly high throughput, but they have a very high seek time when looking for a particular file or frame of an image, potentially much higher than disc-based storage. Tape drives are only one form of removable storage, the most popular is probably CDs/DVDs/BDs and portable flash drives and hard drives. In addition to connecting external drives using USB, Thunderbolt or FireWire, there are also removable hard drive caddies available form various companies that allow a user to 'hot swap' hard drives that are mounted inside a PC or RAID/NAS system used for file storage. There isn't really a standard for these caddies though, so it is necessary to buy them all from the same manufacturer if you want them to be interchangeable, although they are designed to fit into either 5.25 inch or (more rarely) 3.5 inch drive bays.
RAM is installed in slots on the motherboard, or soldered in in some cases, such as in many laptops and embedded systems. Soldered RAM lowers production costs at the expense of ease of repair and upgradability.
Hard Disk Drives work in much the same way as the obsolete floppy drives: they have spinning disks inside, and a read/write head which floats above or below on a cushion of air. They use magnetic fields to store data on the disk, which on hard drives is divided into sectors. Hard Drives (and optical drives, as well as SSDs) normally have a cache of RAM onboard to improve read a write performance. A hard drive head crash is quite undesirable and usually damages a hard drive. It occurs when dust or sudden movement causes the hard drive head to crash into the platter, which can scratch the platter and in some cases shatter it. This is why some laptop hard drives had motion sensors to attempt to detect a drop or fall and shut down the hard drive to try to prevent damage. This is also why new laptops almost exclusively use SSDs.
Solid State Drives or SSDs are used for similar purposes to conventional Hard Drives, but function quite differently. Like hard drives, they also normally have a RAM cache, although some cheap drives forgo it. Most SSDs use flash memory, although Intel's Optane SSDs use an alternative technology called 3D XPoint (which is also used for persistent RAM in DIMM slots, further blurring the lines between RAM and SSDs). Solid State Drives win when it comes to latency (Intel Optane SSDs tends to come out on top in this regard in particular) compared to Hard Drives or Optical Media, since SSDs have no seek time to find the location of data on a physical disk/disc. SSDs also usually beat Hard Drives on raw throughput, especially on read operations but also on most write operations, unless the SSD is using very cheap flash memory that has poor performance. Increasingly, SSDs are using PCIe as their interface rather than using SATA, due to the possibility of lower latency and much higher throughput with PCIe compared to SATA. SATA SSDs are still widely used, however, especially when cost per GB is the most important factor besides performance, since SATA SSDs tend to be cheaper than PCIe SSDs, as they can use lower performing flash memory without as much of an impact.
Tape drives used to be quite common, but are now mostly seen in enterprise backup systems and similar use cases (sometimes video recording still) now. Tape drives work by having a magnetic tape in a cartridge that moves past read and write heads at high speed. The main advantage of tape drives is the low cost per gigabyte, which is why storage solutions such as Amazon Glacier use them. They can also have surprisingly high throughput, but they have a very high seek time when looking for a particular file or frame of an image, potentially much higher than disc-based storage. Tape drives are only one form of removable storage, the most popular is probably CDs/DVDs/BDs and portable flash drives and hard drives. In addition to connecting external drives using USB, Thunderbolt or FireWire, there are also removable hard drive caddies available form various companies that allow a user to 'hot swap' hard drives that are mounted inside a PC or RAID/NAS system used for file storage. There isn't really a standard for these caddies though, so it is necessary to buy them all from the same manufacturer if you want them to be interchangeable, although they are designed to fit into either 5.25 inch or (more rarely) 3.5 inch drive bays.
Comments
Post a Comment