I have to clarify here that my intention was never to compete in any way 
with the other algorithms out there. The BSD checksum is a well-known, 
and pretty weak (16 bits) checksum. The goal behind bsum was only to 
obtain a checksum tool that would run on my 8086 fast enough for me to 
not get frustrated, and just good enough to be reasonably sure that the 
files I just copied from a diskette and then over network-through-
parallel-port didn't get corrupted in the process.


On Mon, 10 Apr 2017 09:48:41 -0700, Ralf Quint wrote:
> On 4/10/2017 6:36 AM, Mateusz Viste wrote:
>> On Mon, 10 Apr 2017 00:56:17 -0500, Rugxulo wrote:
>>> It would be interesting to see some benchmark numbers for that (for
>>> various specific tools, 8086, 386, etc).
>> Just for the fun of it, I did some quick measures on my 386SX PC,
>> computing various checksums of a 2 MiB file. Results below.
>> BSUM (by Mateusz Viste) :  6.0s (100%)
>> CRC32 (by Joe Forster)  :  8.5s  (70%)
>> CRC32 (by Colin Plumb)  : 26.7s  (22%)
>> MD5 (by Colin Plumb)    : 52.9s  (11%)
>> SHA1 (by Colin Plumb)   : 85.7s   (7%)
>> BSUM is the fastest, which is no surprise since the algorithm is
>> extremely simple (4 CPU instructions). The CRC32 computation by Joe
>> Forster is surprisingly fast as well. It's 30% slower than bsum and the
>> binary is 4x times larger (and I suppose the memory usage is also much
>> higher) but that's still quite impressive for a 32-bit checksum.
> Well, most of all, it's kind of comparing apples and oranges. Those
> benchmark tests mean nothing if you don't compare them with the number
> of possible collisions you get for each of them.
> Though that doesn't mean that there aren't use cases where "simple does
> it"...
>>> Splurge on the memory, give it 32 kb or so. It'll "probably" be faster
>>> with a bigger buffer.
> Nope, won't do a thing. Didn't do much good "back in the days" to use
> anything over 16KB and it is even less relevant on modern hard drives
> with MBs of cache. Or SSDs...
> Ralf

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