Glossary

DRAM - Dynamic Random Access Memory is a type of Ram memory. Being of a dynamic build the capacitor is required to be refreshed as apposed to SRAM which is static. Due to its dynamic nature no information is stored within the RAM when your computer is turned off.


SDRAM - Stands for Synchronous Dynamic Random Access Memory. This type of memory Syncronizes with the clock speed that the CPU is configured for. This allows the memory to run at much faster speeds then earlier types of memory modules. SDRAM comes in 168pin Dimm modules for Desktops/Servers and 144pin SoDimm modules for Laptops. 


DDR - Stands for Double Data Rate. This type of ram supports data transfers on both edges of each clock cycle (the rising and falling edges), effectively doubling the memory chip's data throughput. DDR comes in 184pin Dimm modules for Desktops/Servers and 200pin SoDimm modules for Laptops. 


DDR2 - Stands for Double Data Rate (Gen2). The second generation of DDR allowed for further improvement of the speed of the module.  This newer generation can operate effectively at twice the speed of DDR. This generation also allowed the ability to install memory in 'Dual Channel Mode'. DDR2 comes in 240pin Dimm modules for Desktops/Servers and 200pin SoDimm modules for Laptops.


DDR3 - Stands for Double Data Rate (Gen3). The third generation of DDR again allowed for not only significantly improved transfer speeds but also a reduction in power required (a huge 30% power reduction). DDR3 comes in 240pin Dimm modules for Desktops/Servers and 204pin SoDimm modules for Laptops.


DDR4 - Stands for Double Data Rate (Gen4). A further improvement on transfer speeds allowing up to 4266MT/s and again a reduction in voltage to 1.2v DDR4 comes in 288pin Dimm modules for Desktops/Servers and 256pin SoDimm modules for Laptops. 


Compact Flash Cards - Also known as CF cards.  These cards were one of the first forms of mass storage that were using in portable electronic devices such as digital cameras.  The card is still utilised today however they are generally only found in high end DSLR camera. 

We now find that the main use for CF cards is within Industrial devices.  Due to their design they are exceptionally resistant to shock, vibration and dust, while consuming less power and maintaining ultra fast data transfer speeds. They can be implemented in a number of small industrial applications and due to their superb compatibility and durability it makes them suitable for use in standard PCMCIA-ATA equipped devices such as industrial PCs, embedded systems, medical instruments, factory automation systems, network infrastructures and other industrial equipment.


SD Cards (Secure Digital) - Probably one of the most well known types of flash memory for media devices. The SD card was introduced in 1999 and has set the standard for all following SD technologies. The main feature of the SD card over other flash memory cards is that it has a Read/Write switch which allows the user to stop the data on the card being overwritten. SD Cards are available up to 2GB.


SDHC Cards (Secure Digital High Capacity) - The next generation of the SD card allowed for capacities from 4GB to 32GB.  The SD association also brought out classes to allow for SDHC cards to be produced with different read and write speeds.  The classes that are available in SDHC are Class 2, 4, 6 and 10 which relates to the lowest speed at which the card can run at. Unfortunately these cards were not manufactured to be backwards compatible with SD capable devices. SD Cards can be used in devices that can take SDHC card.


SDXC Cards (Secure Digital Extended Capacity) - The latest generation of SD cards allows for capacities from 64GB to 2TB and new speed classes. These  classes are UHS1 and USH3. As with the SDHC cards the SDXC cards were not manufactured to be backwards compatible with SD or SDHC capable devices. However SD and SDHC Cards can be used in devices that can take SDXC card.


Micro SD Cards - These cards were introduced to the market in 2006.  The advancement in technology meant that the latest smartphones and mobile devices had the ability to expand memory without the design being cumbersome. Much like the first generation of the SD card the MicroSD was available up to 2GB.


Micro SDHC Cards - The next generation of the MicroSD card allowed for capacities from 4GB to 32GB.  The SD association also brought out classes to allow for SDHC cards to be produced with different read and write speeds.  The classes that are available in MicroSDHC are Class 2, 4, 6 and 10 this relates to the lowest speed at which the card can run at. Unfortunately these cards were not manufactured to be backwards compatible with MicroSD capable devices. MicroSD Cards can be used in devices that can take MicroSDHC cards.


Micro SDXC Cards - The latest generation of SD cards allows for capacities from 64GB to 2TB and new speed classes. These  classes are UHS1 and USH3. As with the Micro SDHC cards the MicroSDXC cards were not manufactured to be backwards compatible with SD or SDHC capable devices. However MicroSD and MicroSDHC Cards can be used in devices that can take MicroSDXC card.


USB Drives - The most common use of USB flash drives is to transport and store personal files, such as documents, pictures and videos or to backup data from larger drives. With drives ranging from 4GB to 256GB and technology covering both USB 2.0 and 3.0 these are the smallest version of the external drives.