Solana’s 90% slowdown: Is quantum-safe security killing SOL’s speed?

Can a blockchain achieve both scalability and speed, or is it forced to prioritize one over the other? 

Solana’s latest move has put this question in the spotlight for traders and developers. For years, Solana’s high-speed powered growth in its stablecoin market and transaction volume.

Put simply, its fast throughput allowed the network to handle huge transaction loads while maintaining strong on-chain liquidity.

Look at Solana’s de-dollarization push: Dune data, as of press time, showed that Unique Senders of non-USD stablecoins on the network nearly tripled year-on-year, driven by EURC and BRZ adoption.

From a strategic standpoint, the network is clearly diversifying its stablecoin portfolio, laying the groundwork for broader DeFi expansion.

From a technical perspective, however, this growth highlights Solana’s [SOL] strong underlying network fundamentals. Its high throughput, fast confirmation times, and robust on-chain liquidity have enabled it to support complex financial activity at scale, something that many competing blockchains still struggle with.  

However, recent quantum testing revealed a trade-off, raising questions about whether Solana can keep its edge.

For context, Solana is working with Project Eleven to test quantum-safe signatures. Basically, it’s a way to protect the network from potential attacks by future quantum computers.

The catch?

Early tests show some big compromises.

Quantum-safe signatures are up to 40× larger, and the network ran roughly 90% slower. In simple terms, making Solana quantum-resistant could seriously slow down transactions, forcing the network to juggle speed, scalability, and security all at once.

That naturally brings up a tough question: Can Solana stay fast and secure while keeping its edge?

Speed vs security: Solana’s edge over Ethereum faces a critical test

The trade-off is clear: Either lock in security and slow down, or keep speed and take on more risk.

Recent quantum testing exposed this trade-off. To safeguard the network against future quantum attacks, Solana accepted a roughly 90% slowdown in speed.

As AMBCrypto noted, this is particularly challenging for Solana, since speed has long been its defining advantage over other layer-1s, especially Ethereum [ETH].

The impact of that advantage has been enormous.

According to Chainspect data, Solana’s high throughput has given it a massive edge over Ethereum across multiple metrics. Look at transaction volume: Solana has processed 31× more transactions than Ethereum, reaching a staggering 106 billion transactions in total.

Notably, this scalability comes straight from Solana’s high speed. 

As the chart above shows, Solana ranks second among all blockchains with 1,191 real-time transactions per second (TPS), compared to Ethereum’s 25.99 TPS. This allows Solana to handle massive transaction loads efficiently, giving it a clear edge in DeFi, something slower L1s like Ethereum still struggle with.

According to AMBCrypto, that’s why the recent quantum testing is such a crucial moment. 

A 90% slowdown in speed puts Solana’s signature advantage under pressure. Even more, it could slow DeFi growth just as competition from Ethereum is heating up.

This, in turn, forces the network to prove it can stay fast, secure, and ahead of the pack. Otherwise, it risks losing the edge that has long set it apart.

Final Summary

• High throughput and fast TPS let Solana handle massive transactions, support DeFi growth, and outperform Ethereum across key metrics.
• Moving toward quantum-safe security slows the network by 90%, forcing Solana to balance speed and security, or risk losing its lead.