DRAM chips are small but normally inexpensive because they usually require only one capacitor and one transistor to represent each bit.

In DRAM chips, the capacitors must receive an electric pulse every 15 milliseconds (ie. hundreds of times a second) to maintain the charge; if this does not happen, it looses the memory until a new charge and new memory is written to the chip.

All current day computers use small boards of dram to supply memory. These boards are called ‘DIMM’ (Dual Inline Memory Module) and ‘SIMM’ (Single Inline Memory Module) modules.

The RAM memory of a computer can be increased either by:

1. Replacing current SIMMs or DIMMs with higher spec ones (ie having higher storage capacity).
2. Adding more modules to vacant slots on the mother board

Reasons For Adding Memory

• Insufficient memory may result in a computer taking a lot of time to perform a task; or perhaps even crashing during a task.
• If problems such as this occur; the RAM memory capacity should be increased to, at least, the minimum memory requirements of the application(s) being run - check the literature supplied with software being used.
• The computer can also benefit from RAM upgrade if the computer will be using lot of software applications which require a huge amount of memory. For example if you are running applications like Photoshop, Microsoft outlook, Microsoft excel, illustrator all one time then the computer will start freezing due to insufficient RAM.
• Problems When Installing Memory
• When installing memory, the following problems can occur:
• Damaged chips (when installing individual chips; look carefully at chips before inserting. Never force a chip)
• Damaged SIMM or DIMM modules (as with chips, never force a module into a motherboard. They should easily click into place)
• Inappropriate jumper switch settings
• Electrostatic discharges damaging a chip (hold memory module at the ends only, to avoid contact with the memory chips and the lower connecting edge – gold fingers).
• Compatibility issues. If the motherboard supports dual channel memory, then all modules should be identical i.e. having same speed, same capacity and ideally from the same manufacturer. Meeting these criteria will prevent compatibility issues when installing new or upgrading RAM modules.
• Seating Issues. Incorrect seating of the module(s) in the slot will result in system not seeing it and thus causing an error message when powering up. The module(s) must therefore be perfectly aligned with the slot, both of which are keyed with notches to ensure correct orientation. Then press down the memory module with sufficient force so that the plastic retainer clips lock into position automatically. When the retainer clips are locked into position this will guarantee that the memory module is perfectly seated.

   

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