This is a discussion on Re: 0.9.8: cfb_enc.c bug? and AES speed on Win64/x64 - Openssl ; Tomas Svensson wrote: | | Some OpenSSL-algorithms are slower on x64, like RSA. SHA1 and RC4 seem to | be faster [...] Cases where an OpenSSL algorithm is slower on AMD64 than on i386 are almost always due to a ...
Tomas Svensson wrote:
| Some OpenSSL-algorithms are slower on x64, like RSA. SHA1 and RC4 seem to
| be faster [...]
Cases where an OpenSSL algorithm is slower on AMD64 than on i386 are
almost always due to a substandard AMD64 implementation. For example,
some algorithms are written using hand-coded assembly when compiled
for i386, and a generic (slower) C language implementation when
compiled for AMD64.
Fortunately, such cases are becoming less and less common, as more and
more algorithms are being optimized for AMD64 (for instance I contri-
buted an assembly version of MD5 for AMD64, new in 0.9.8). But I think
that more work is needed, as about 50% of the algorithms are still
faster on i386.
You said that RSA is slower on AMD64 ? This is unmistakably wrong, or
at least, something must have gone terribly wrong during your
benchmark. RSA heavily benefits from 64-bit arithmetic and by
consequent AMD64 has a clear advantage over i386 (it is usually up to
Marc Bevand http://epita.fr/~bevand_m
Computer Science School EPITA - System, Network and Security Dept.
OpenSSL Project http://www.openssl.org
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