In this article we will see what are the minimum requirements to start a full node (validator) on the main blockchains with the Proof Of Stake consensus algorithm. I remind you that for these blockchains, staking is essential to validate transactions and to secure the network. In this case the cryptocurrency is pre-mined (unlike Bitcoin's consensus algorithm, Proof Of Work, which will allow mining until 2140). These hardware pre-requisites influence the decentralization of a blockchain: the more difficult it is to become a validator and expensive to maintain a node, the more a blockchain tends to be centralized. Then there are the exceptions, for example Solana has about a thousand validators (not a few) but it is perhaps the blockchain with the highest hardware requirements (although in truth there are few validators that validate transactions). If you don't have a NASA device and $100,000 you will never become a Solana validator! There are also blockchains that have a maximum number of validators (e.g. Cosmos which has 150). Another aspect to take into consideration is having a fast connection. Obviously these characteristics may vary over time so they are only indicative and not definitive.

The parameters to take into consideration are:
-CPU (with Central Processing Unit it refers to the processor therefore to the processing of operations in the form of information. Initially to improve performance, the CPU frequency was simply increased, however this led to greater overheating and energy consumption so it was decided to increase the number of cores. The core is precisely a physical component of the CPU and is the smallest processing unit capable of carrying out the calculations necessary to perform a certain task. Dual, Quad and Octo core is the number of processors capable of dividing a certain task (so a multi-core CPU performs better, consumes less power and produces less heat)
-RAM (Random Access Memory is a volatile memory in which information for the execution of a program is stored. As the RAM increases, the applications that can be started simultaneously increase without the device crashing or slowing down)
-Storage SSD (SSD refers to storage space. Successors of HDDs, they are faster, lighter and more durable. Another difference is that they use less power)
-Min Balance (it is the minimum to be staked to start a validator node and it is variable according to the blockchain)

Let's see the main ones (some parameters may vary over time but are indicative):

-Ethereum: CPU Cores (4), RAM (8-16 GB), SSD (600GB), Balance (32 ETH + fees)

-Binance Smart Chain: CPU Cores (8), RAM (16GB), SSD (1000GB), Balance (10,000 BNB)

-Solana: CPU Cores (12-16), RAM (128-256GB), SSD (2000GB), Balance (1,1 SOL/Day)

-Cosmos: CPU Cores (4), RAM (16GB), SSD (500GB), Balance (21,500 ATOM)

-Polkadot: CPU Cores (4-8), RAM (32-64GB), SSD (500GB), Balance (350 DOT)

-Avalanche: CPU Cores (4-8), RAM (4-16GB), SSD (200GB), Balance (2,000 AVAX)

-Polygon: CPU Cores (8), RAM (32GB), SSD (2500GB), Balance (1 MATIC)

-Cardano: CPU Cores (4), RAM (16GB), SSD (160GB), Balance (500 ADA)

-Cronos Chain: CPU Cores (4), RAM (4GB), SSD (25GB), Balance (No Min Stake)

-VeChain: CPU Cores (4), RAM (8GB), SSD (500GB), Balance (25,000,000 VET)

-Tron: CPU Cores (8-16), RAM (32GB), SSD (1500GB), Balance (9,999 TRX)

-Near: CPU Cores (4-8), RAM (8GB), SSD (200GB), Balance (67,000 NEAR)

-Aptos: CPU Cores (4), RAM (8GB), SSD (300GB), Balance (1,000,000 APT)

-Algorand: CPU Cores (2), RAM (4GB), SSD (100GB), Balance (0.1 ALGO)

-Harmony: CPU Cores (4), RAM (16GB), SSD (1500GB), Balance (10,001 ONE)

-Fantom: CPU Cores (4), RAM (16GB), SSD (1500GB), Balance (500,000 FTM)

-Mina Protocol: CPU Cores (8), RAM (16GB), SSD (100MB), Balance (-)

The blockchain with the highest requirements is definitely Solana. Surely even the 32 ETH are not within everyone's reach. The minimum staking for the BSC Chain is absolutely prohibitive, actually there are only 21 nodes (and they are almost all from Binance!). In general the Cosmos world has a maximum number of validators. For example it's 150 for Atom. If you are above position 150 as a delegate Atom you do not get rewards because you do not validate transactions. When you do Dot staking, each node has a "saturation" level beyond which you no longer get rewards: this is used to decentralize the network. They are counterbalanced by Algorand in general and Mina Protocol in terms of storage space (this blockchain weighs only 21 KB!).

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