How a $2,100 server chip outperforms a high-end GPU rig against Argon2 password hashes

For several years the cybersecurity industry has assumed that throwing more graphics processing units (GPUs) at a password-cracking problem would dramatically accelerate results. New research from Specops Software, however, suggests that when it comes to modern password hashing algorithms, the economics of cracking are becoming far more complicated.

The study focuses on Argon2id, a variant of the Argon2 password hashing algorithm that emerged as the winner of the 2015 Password Hashing Competition and is widely regarded as one of the strongest approaches for protecting stored passwords.

According to the research, Argon2id significantly reduces the performance advantage that attackers typically gain from powerful GPU hardware. Testing conducted on a system equipped with eight Nvidia RTX 5090 graphics cards revealed a cracking rate of approximately 490 hashes per second, compared with roughly 221 billion hashes per second for SHA-256 on the same hardware. This makes Argon2id around 451 million times slower to crack than SHA-256 under equivalent conditions.

Argon2id is the recommended password hashing algorithm for modern backend applications.

In practical terms, a password that could be recovered in about one second when protected with SHA-256 would require more than 14 years to crack when secured using Argon2id.

Why Argon2 changes the game

The key to Argon2’s effectiveness lies in its design. Unlike traditional hashing algorithms that primarily demand processing power, Argon2 is described as a memory-hard function. This means each password-guessing attempt requires substantial memory resources, limiting the ability of attackers to gain massive performance boosts simply by adding more GPU cores.

Memory-hardness has become increasingly important as cloud computing platforms and high-performance graphics hardware make traditional brute-force attacks more accessible. Rather than relying solely on computational speed, Argon2 forces attackers to contend with memory constraints, raising both the complexity and cost of password-cracking operations.

The result is a notable shift in the balance between defenders and attackers. While older algorithms such as MD5 and SHA-family hashes can often be attacked efficiently using specialized GPU clusters, Argon2 narrows the performance gap between consumer graphics hardware and conventional server processors.

The surprising CPU advantage

Perhaps the most striking finding from the research is not Argon2’s resistance to GPUs, but where the performance advantage ultimately shifts. Specops found that the password recovery tool mdxfind achieved around 730 hashes per second when running on a single AMD EPYC server processor costing approximately $2,100. This throughput exceeded that of the eight-GPU configuration, despite the graphics-card setup costing many times more.

The finding challenges a common assumption in cybersecurity that larger GPU investments always translate into superior cracking performance. Against memory-hard algorithms, there appears to be a point where adding more graphics hardware delivers diminishing returns. Instead, carefully matched processor and memory configurations may offer attackers a more cost-effective route.

For organizations evaluating password security, the message is nuanced. Argon2 successfully raises the barrier to brute-force attacks and substantially increases the resources required to recover passwords from stolen databases. However, it does not make password cracking impossible.

The research also highlights an enduring reality of cybersecurity: even the strongest hashing algorithm cannot protect a password that has already been compromised. If a user reuses a password that has appeared in a previous breach, falls victim to phishing, or loses credentials through malware such as an infostealer, the strength of the underlying hashing algorithm becomes largely irrelevant. Attackers possessing the plaintext password do not need to crack the hash at all.

This observation aligns with a broader industry trend toward layered identity protection strategies. Password managers, multifactor authentication, breached-password screening, and continuous monitoring are increasingly viewed as essential complements to strong password hashing.

Alongside the publication of the new research, Specops announced the addition of more than 60 million newly compromised passwords to its Breached Password Protection service, drawing data from threat intelligence sources and honeypot collections.  The company recommends that organizations encourage minimum password lengths of 15 characters and actively block known compromised credentials.

The study serves as a reminder that password security is an evolving contest between defensive technology and attacker innovation. Argon2 remains one of the strongest available password hashing approaches and continues to offer a significant improvement over legacy algorithms.