Hashcat, the de-facto password cracking tool that recently went open-source, works very well on both AMD and Nvidia GPUs.
One problem however, was that when everyone went out to buy their GTX 980’s and other Maxwell-based cards, they discovered that rule-based attacks on wordlists were slower than brute-force attacks on some algorithms. They were also just slow compared to other similar-spec cards from AMD. Obviously, wordlist and rule-based attack speeds depend on how many hashes you have, and how many wordlist candidates are keeping the GPU’s busy. However, even when properly optimized, and due to OpenCL constraints, the speed of Maxwell GPU’s in wordlists+rule modes lags behind their AMD cousins.
Until now that is.
Thank’s to a recent tweak by atom (Hashcat’s developer) we are enjoying a major speed boost for Maxwell-based cards. The tweak was a work around for how OpenCL is used by Hashcat with Maxwell-based Nvidia cards.
I have decided to do some benchmarks to show the difference.
the benchmarks were done using;
- 1 SHA256(p./s), MD5, NTLM & PHPass Hash
- A 1GB wordlist to ensure that all GPU’s are 100% utilized during our measurement run.
- The d3ad0ne.rule ruleset that ships with Hashcat
- A timer of 60 seconds to let everything settle and run.
- No reboots, no driver changes, no extra Hashcat settings (all on automatic).
- 4 measurements of speed during the 60 seconds, averaged to a final speed.
The Benchmarks were done in the following manner;
- Old Hashcat + 1 980 GPU
- New Hashcat + 1 980 GPU
- Old Hashcat + 6 x 980 GPUs
- New Hashcat + 6 x 980 GPUs
All the results are published in the graphs below, which indicate the changes: