When deciding on the RAM for your server, you will see suggestions based on what the server is intended for, which help set the bottom threshold. However, going bigger is always recommended: the more RAM, the better the performance. Let’s take a closer look at why this is the case.

Servers need plenty of RAM because fast and efficient performance requires more capacity as your database grows. Larger RAM is needed for a larger number of users and dynamic content. The operating system (OS) size and expected growth rate should also be considered.

1. A Faster Server Needs More RAM

RAM (Random Access Memory) is a volatile memory structure that can only hold information temporarily, unlike a hard disk drive (HDD). Its key function is optimizing processing operations, which includes all the apps that run on the server and all the stored and retrieved data.

The RAM size determines how much data it can hold simultaneously. When RAM runs out of space, it must remove older data and return to the HDD to acquire new files. The smaller the memory capacity, the more often your RAM will be forced to delete data and access it from the HDD whenever you need it again.

Larger capacity, on the other hand, can significantly decrease the number of required cycles. The more data that can be stored in RAM, the less it will have to reach out to the HDD, allowing for faster speed.

RAM speed is also influenced by frequency, measured in MHz, and latency, often referred to as CAS latency. Frequency measures how many read-write cycles your RAM can perform per second, while latency measures how many clock cycles it takes for the RAM to process and execute a command from the CPU. Together, these factors determine the overall performance of your RAM.

2. Larger Databases Need Larger RAM Capacity

The size of the RAM is directly tied to the size of the database. The larger the database, the more capacity is required to process its information effectively. This factor is crucial when determining the optimum RAM size.

Here are general recommendations for SQL servers to use as a reference:

Database Size	RAM Size
10-59 GB	74% of DB size
60-224 GB	23% of DB size
225-600 GB	13% of DB size
600+ GB	6% of DB size

As databases grow, the percentage of database size that determines the required RAM capacity drops. This is because other factors contribute to the minimum RAM size besides the database, including the space reserved for the OS.

3. More Users Increase the Load on the RAM

The number of users is another factor that can require more RAM. The more people using the server at a given time, the greater the load on your RAM. To ensure it can handle the load, you must provide enough RAM to process user requests.

For small businesses and servers with local purposes, this factor may not be significant. However, for larger scopes, you should account for the number of users when determining the RAM size. A general rule is to add 1-2 GB for every 5 additional users. For large-scale projects, you may need significantly more, often requiring multiple servers for hundreds of thousands of users.

4. Dynamic Content Needs More RAM

The types of content a server handles also influence the required RAM size. Dynamic content requires more RAM than static content due to its complexity.

Static Content: Stored in its final form and displayed similarly to all users. Examples include website articles, YouTube videos, and pictures. It’s simple to process and doesn’t demand much RAM capacity.
Dynamic Content: Changes with each request based on user conditions. Examples include messengers, ads, and personalized recommendations. It’s more complex to process and requires more RAM.

The more dynamic content a server handles, the more RAM is required for decent performance. For simple home servers dealing mainly with static content, this won’t be a major issue.

5. Leave Space for the OS

A portion of the required RAM size must be reserved for the system files. The space needed for the OS depends on the overall RAM size. General recommendations for OS RAM capacity are:

1 GB of default space.
1 additional GB for every 4 GB of RAM up to 16 GB.
1 additional GB for every 8 GB of RAM above 16 GB.

For example, with 32 GB RAM:

Start with 1 GB of default capacity.
Add 4 GB for the first 16 GB of RAM.
Add 2 GB for the remaining 16 GB of RAM.

Total: 1 + 4 + 2 = 7 GB reserved for the OS.

Most software will specify the minimum requirements and recommended optimum RAM capacity for the OS, along with the maximum RAM size it can handle.

6. Plan for Growth

Always plan ahead and consider your growth expectations. Sometimes, the RAM size recommendations may seem excessive, but it’s wise to include more capacity to ensure the server can support future growth.

Calculate the required RAM size based on anticipated database and user growth. Consult IT specialists for an accurate assessment of your prospects and the suggested optimum RAM capacity suitable for potential growth. Upgrading the memory size later requires taking the server down for maintenance, which can interfere with work and bring extra costs.