Virtual memory functions as extra memory, providing system support like additional RAM. Virtually memory swaps non-essential data to a temporary file in the hard disc or permanent storage. It can call the data later when necessary. Virtual memory can be super handy when a device or processor needs a memory boost. It’s also less costly than the actual RAM. However, such memories are not without disadvantages. One must be aware of the pros and cons of virtual memory to avoid unexpected consequences.
Types of Virtual Memory/ RAM?
The first step of knowing about virtual memories is to learn their classification. Computers handle virtual memory either through paging or segmentation. So, the type of virtual memory depends on how it’s being handled. Below is a bigger picture about them:
Paging
This kind of virtual memory operates by partitioning memory into parts known as paging files. When RAM is full, it moves any unused pages to the specific part of a hard drive designated for virtual memory. This procedure is executed by the computer utilizing a swap file. A swap file is a predefined area on the hard drive for expanding the virtual memory of the RAM. Moving unnecessary data to the hard drive makes some free RAM space for necessary activities and guarantees that the system never runs out of actual memory.
The computer utilizes page tables to convert virtual addresses into physical addresses. This is done as only a part of the instruction processing system by the Memory Management Unit of the computer.
Segmenting
Another technique of controlling virtual memory is called ‘segmenting’. This process splits virtual memory into segments of different lengths and transfers unused segments from the virtual memory of the computer to the hard drive. Segment tables, like page tables, keep track of whether a segment is stored in the memory or as a physical address.
The difference between segmenting and paging is that segmenting parts memory into different lengths, while paging divides memory into equal-sized pieces. In paging, the computer’s hardware decides section size, while in segmentation, the user may choose segment length.
Benefits of Virtual Memory/ RAM?
Having a virtual memory can be of real advantage for the users, especially in critical situations. Here are some of the best advantages that come with virtual memory.
Segmented Speed Rise
Virtual memory doesn’t bother using the whole RAM to gain a certain level of speed. Instead, it assists a particular segment of the whole program to gain an expected speed. It uses the segment only when the segment of the program needs to execute a necessary instruction or run another program.
Multi-programming Environment
If users need to make a multi-programming environment, they should use a virtual memory system. Such memory provides the extra support that smoothens the multi-programming environment. Furthermore, virtual memory helps users do large programs into comparatively smaller programs. There is no specific multi-programming limit.
Memory Share
Programmers and designers often need systems that can share data or information between memory. They will find a virtual memory system quite helpful. The process can communicate data and instructions via and between memory.
Data Placement
Another big perk with virtual memory is users can place their data and codes anywhere in the physical memory without a relocation. These data or codes can be read anytime from the disc. Users will find the process larger than other physical memories. Users will get more space for virtual addresses compared to physical memory.
Checks External Fragmentation
When unused memory is split into smaller segments and interleaved with assigned memory, this is known as external fragmentation. It is considered an issue as an algorithm for storage allocation, especially when these algorithms fail to effectively arrange memory utilized by applications.
No Memory Holes
Memory holes may cause unusual fragmentation. However, virtual memory overcomes this problem since it does not contact the physical memory management unit. Furthermore, each program has its individual mapping, and users can utilize the mapping to place their program data anywhere they want in the RAM.
Security
Each program has the ability to access any 32bit memory address. The issue arises when two programs use the same address in address space to keep their results. In that case, the output of one program may be altered by another, resulting in users not receiving the desired outcome. It is the most serious issue that virtual memory can address.
Disadvantages of Virtual Memory/ RAM?
It might sound a bit queer, but virtual memory has some disadvantages on its side. Before having a system that supports virtual memory, users should know about all these disadvantages. Thus, they will know how much to expect and also the limitations.
– If the system is utilizing virtual memory, applications can run and execute slower. Because virtual memory executes things.
– Switching between apps will most likely take a longer time.
– Virtual memory reduces the amount of hard disk space available for your usage.
– It has a negative impact on system stability.
– It enables bigger programs to operate on systems that do not have enough physical RAM to execute them on their own.
– It can’t provide support at the level a RAM does.
– It has a detrimental impact on a system’s overall performance.
– It occupies the storage space, which might otherwise be utilized for long-term data storage.
Conclusion
Virtual memory is an inexpensive way to extend the RAM capacity of a system. It can be an effective alternative to purchasing new RAM. However, Virtual RAM has both advantages and disadvantages for a user. That’s why users should figure out why they need a virtual memory in the first place. Then they should estimate whether it will provide what he wants. Without estimating these aspects, using a virtual memory system can hamper their work.
Source: United News of Bangladesh