New research has produced a result that upends a piece of common wisdom in cybersecurity. When it comes to cracking passwords protected by the Argon2 algorithm, a single server processor costing about $2,100 outran a rig of eight high-end graphics cards worth more than $40,000. For years, the rule of thumb has been that more GPUs mean faster cracking. Against Argon2, that rule breaks, and understanding why says a lot about how modern passwords are actually protected.
The findings come from time-to-crack research published by Specops Software, an Outpost24 company, on 16 July 2026. The study tested how Argon2, the algorithm that won the 2015 Password Hashing Competition, holds up against the kind of hardware attackers use today.
What is Argon2, and why is it so hard to crack?
When a service stores your password, it does not (or should not) store the actual characters. Instead, it stores a “hash”, a scrambled output produced by a one-way algorithm. When you log in, the service hashes what you typed and checks whether it matches.
Attackers who steal a database of hashes then try to reverse them by guessing billions of passwords per second and hashing each guess until one matches.
The speed of that guessing depends heavily on the algorithm. Older hashes like SHA256 are fast to compute, which is great for performance but terrible for defence, because it lets attackers test enormous numbers of guesses cheaply.
Argon2 was designed to do the opposite. It is memory-hard, meaning each hash calculation demands a large chunk of memory, not just raw processing power. That single design choice strips away most of the advantage attackers buy when they stack up graphics cards.
Argon2 comes in variants, and the research focused on Argon2id, the recommended general-purpose version.
Argon2 vs SHA256: the numbers that show the gap
To measure the difference, the Specops team tested Argon2id on a rig of eight Nvidia RTX 5090 graphics cards, the same class of hardware cloud providers rent out for around five dollars an hour.
The results were stark:
- Argon2id managed just 490 hashes per second.
- SHA256 managed around 221 billion hashes per second on the same equipment.
That makes Argon2id roughly 451 million times slower to crack than SHA256. Put in plain terms: a password that takes one second to hash with SHA256 would hold out for more than 14 years under Argon2id. For anyone trying to brute-force a strong, random password on a GPU rig alone, the task becomes effectively unrealistic.
The twist: where the cost curve bends
Here is where the research gets counterintuitive. Argon2’s memory-hard design punishes GPUs specifically, but a well-matched processor is a different story.
Using a tool called mdxfind, the team hit 730 hashes per second on a single AMD EPYC server processor costing about $2,100, actually outpacing the eight-card GPU rig, where each card alone costs upwards of $5,000.
Against Argon2, raw GPU spending simply stops buying speed. Cheap, well-suited hardware can still recover some hashes, and it can do so more efficiently than a far more expensive graphics setup.
The lesson for defenders is subtle but important: stronger hashing raises the cost of an attack, but it does not remove the risk. Determined attackers with the right hardware can still make progress.
You may also be interested in Cybersecurity Best Practices Every Business Must Follow.
The catch: Argon2 can’t protect a password that an attacker already has
There is a much bigger limitation that no hashing algorithm can solve. All of this maths about cracking speed only matters if the attacker has to guess the password in the first place. It does nothing for a password an attacker already holds.
If your password has leaked in a previous data breach, been captured through a phishing attack, or harvested by an infostealer infection on your device, the strength of the hashing algorithm is irrelevant. The attacker simply logs in. Weak and predictable passwords can also still be guessed quickly, regardless of the algorithm behind them.
That is why strong hashing has to sit inside a wider security strategy rather than stand in for one.
“Argon2 is a real step forward that makes brute forcing far more expensive than older algorithms,”
said Darren James, Senior Product Manager at Specops Software.
“But harder is not the same as impossible, and no hashing algorithm can protect a password an attacker already has. Strong hashing needs to be combined with policies that prevent weak, predictable and already-compromised passwords from being used.”
What you should do about it
The research points to a few practical takeaways for individuals and, especially, for organizations:
- Use long passwords. The study recommends a minimum length of 15 characters. Length is one of the most reliable ways to push cracking time out of reach.
- Don’t reuse passwords. A password exposed in one breach becomes a key that unlocks every other account where it was reused. A password manager makes long, unique passwords practical.
- Screen against compromised credentials. For businesses, the most effective defense is to block passwords that are already known to be exposed. Specops’ research lands alongside an update to its Breached Password Protection service, which added more than 60 million newly compromised passwords gathered from the company’s honeypot network and threat intelligence sources. The service checks passwords in Active Directory against known breached credentials and prompts users to change exposed ones before attackers can use them.
Also read: Best eCommerce Cybersecurity Tools.
The bottom line
Argon2 is genuinely one of the strongest password-hashing algorithms available, and this research confirms it dramatically raises the cost of brute-force attacks compared to older options like SHA256. But two things are worth remembering. First, “harder to crack” is not the same as “uncrackable”; a modestly priced, well-matched CPU can still outperform an expensive GPU rig against it. Second, and more important, no algorithm can defend a password that has already been stolen or reused.
Strong hashing protects the vault. Good password habits and breach screening make sure the attacker never gets the key in the first place.
