The project and its database are currently hosted on a server with SSD. However, I am planning to transfer everything to a new web hosting where I will deploy the project on two separate servers: one for tasks and database, and the other purely for the project itself and its caching. The hosting options available provide VPS on KVM virtualization in either HDD + SSD or SSD configurations, and I am considering the former as it is more cost-effective. The database and Rails tasks do not require an SSD, and a bundle of HDD + SSD would suffice. As for the project server, I do not believe it needs an SSD either. Do you think my decision is reasonable?

While SSDs offer faster read/write speeds, they can be expensive. In some cases, an HDD + SSD bundle may suffice, depending on the project's requirements. It's best to evaluate your needs and budget before making a decision.

It's not entirely clear why there is a move to save money on SSDs when they seem sufficient for two servers. Generally speaking, it is recommended to stick with SSDs if your financial situation allows for it.

When comparing HDDs and SSDs, data access is commonly categorized as either sequential or random. In reality, there is a mix of the two, but SSDs are known for their fast random access, making them ideal for databases (which rely heavily on random access). On the other hand, the application would likely only use the disk for bootstrapping and logging, making disk speed irrelevant.
 
Although these are general recommendations, variables can change depending on the server setup, and performance may be affected. If your project is not heavily loaded and loading speeds are reasonable, you may not need an SSD. However, if you plan on using a swap file, it would be criminal not to use an SSD.

Regarding HDD + SSD configurations, it's unclear what this means exactly. If it's just two drives mounted at different points, placing the database on an SSD would suffice and be a good option.

The criteria for "suitable" and "not suitable" have not been defined, making it difficult to determine the best option. Additionally, it's unclear how SSD/HDD + RAM will be utilized, as it depends on factors such as the database size, requests, and software cache.

It can be said with certainty that the SSD option is no worse than SSD + HDD, but it's uncertain how much better it could be.

In such conditions, a practical approach would be to start with a monthly tariff with SSD and determine the average performance characteristics of the installed software. After a month, switch to a "lower" tariff and perform the same measurements. Based on the results, a decision can be made. If the second option is unsatisfactory and a better option is desired (with willingness to pay for it), returning to the "expensive" tariff plan would be a viable solution.

Additional information: It's important to carefully evaluate hosting options based on the specific requirements of your project. Cost-effectiveness and performance are both important factors to consider, and it's wise to conduct tests and measurements before making a decision. As technology advances, new options may become available, so it's important to stay informed and be open to changes.

Compared to traditional hard disk drives (HDDs), solid-state drives (SSDs) have several advantages:

Speed: The NAND flash memory used by SSDs results in faster read and write speeds, leading to quicker startup times and application loading.

Noise: The physical spinning disks used by HDDs can generate a significant amount of noise, while SSDs are completely silent due to their lack of moving parts.

Durability: The absence of moving parts in SSDs means they are less susceptible to damage caused by bumps or drops, making them more suitable for use in portable devices.

Energy Efficiency: SSDs consume less power than HDDs, helping to conserve battery life in laptops and other mobile devices.

Reliability: Due to their lack of moving parts, SSDs are generally more reliable than HDDs over the long term as there is less risk of mechanical failure.

Additional information: The choice between HDDs and SSDs depends on individual needs and budget. For those who require faster read and write speeds, greater durability, and longer battery life, SSDs are a great option. While they may be more expensive than HDDs, the benefits can make them worth the investment in specific cases.

A hard disk (HDD) consists of a rotating disk on which the system and user files are stored, with a read-write lever used to read or write information. Hard drives are known for their reliability and cost-effectiveness in terms of "price per gigabyte" ratio.

On the other hand, solid-state drives (SSDs) use NAND memory chips to store data, making them faster and more durable than HDDs. There are no moving parts in SSDs, making them less susceptible to damage from vibrations and shocks. The capacity of SSDs is determined by the number of memory chips, with the most accessible option being QLC memory, although MLC is faster and more durable.

Both hard drives and SSDs are connected via the SATA interface, but SSDs can also use the newer NVMe technology for even faster speeds. When it comes to price and memory capacity, HDDs offer the greatest amount of storage per dollar, but SSDs are becoming increasingly affordable.

When building a PC, it's recommended to choose an SSD with a capacity of 256 or 512 gigabytes for faster performance and convenience. Installing the operating system and frequently used programs on the SSD will result in a noticeable difference in speed compared to using a hard drive. SSDs can operate at speeds of around 500-600 megabytes per second, whereas HDDs average around 100-150 megabytes per second.

Additional information: While the choice between HDDs and SSDs ultimately depends on individual needs and budget, SSDs are generally preferred for faster read and write speeds and greater durability. The decreasing price gap between HDDs and SSDs makes SSDs a more attractive option for those looking for better performance without breaking the bank.

Whether you need an SSD for your database and Rails tasks depends on the specific requirements of your project. SSDs provide faster read/write speeds, which can be beneficial for applications that involve frequent data retrieval or heavy database operations. If your database and Rails tasks involve complex queries, large amounts of data, or require quick response times, an SSD can significantly enhance performance.

However, if your project has more modest requirements and does not heavily rely on intensive database operations, an HDD might be sufficient. HDDs can still handle regular read/write operations but are generally slower compared to SSDs. Additionally, HDDs may have lower input/output operations per second (IOPS) and latency compared to SSDs.

Consider assessing the workload demands of your database and Rails tasks to determine if the improved performance of an SSD is necessary for your specific use case.