Your own code and their run on a different platform:

Code:

$ ll
total 31856
-rw-r--r--  1 pkumarpr  ipg       144 Apr 21 15:27 sha1_.pl
-rw-r--r--  1 pkumarpr  ipg  32544556 Apr 21 15:36 usr.bin

Code:

$ cat sha1.pl
use Digest::SHA1;
binmode(STDIN);
my $s = Digest::SHA1->new;
while (read(STDIN, $buf, 1024)) {
    $s->add($buf);
}
print $s->hexdigest . "\n"

Code:

$ time perl sha1_.pl < usr.bin
bad603823684e49866e5c744d560992d34743338

real    0m1.520s
user    0m0.368s
sys     0m0.196s

$ time sha1 < usr.bin
bad603823684e49866e5c744d560992d34743338

real    0m0.181s
user    0m0.128s
sys     0m0.053s

The above run itself is around 8X performance difference in performance with standard sha1sum utility.



The above was run on a FreeBSD7.1 machine; -a very busy build machine, we have in lab!!!

One should not conclude for the overall scenario with few runs on simple tests performed on a type of H/w & one platform only; because this might differ drastically in other environment especially a controlled ones like appliances/devices;
wherein something might be configured to run with 100% CPU utilization and with hi-priority (in multi-core/CPU environment). I think you should have considered this too!!!


Now about 440x performance: You calculated it with the data I described, great!!! You still don't know the environment my c-program ran and I got the kind of performance difference.


Fact:

IBM ISS Proventia GX-series IPS devices, under FIPS mode, run a boot-time integrity check (with SHA1 hash), of the entire disk, in just around 3 seconds (around 5 seconds on low end the models).

The devices are in public domain and you should have a look at it.

Under similar conditions that Perl script based utility had a 22-mintues of run!!!