Benchmark Contest:Count character ratio in DNA file

RULES:
The program must count(without prior knowledge of file beyond its format) GC-content of source file.
GC-content is fraction of GC vs AT chars found in the file expressed as floating point number. http://en.wikipedia.org/wiki/GC-content
source file https://github.com/dubst3pp4/GC-Content-OOC/blob/master/Homo_sapiens.GRCh37.67.dna_rm.chromosome.Y.fa

http://saml.rilspace.org/moar-languagez-gc-content-in-python-d-fpc-c-and-c

tl;dr: C wins. ...but no Asm in the comparison. And talking about reading a file "lines" at a time? WTF, are these amateurs? Even the C version there is rather slow - around 2 clocks/byte.

But if you take this...

C = 63h = 0110 0011b
G = 67h = 0110 0111b
A = 61h = 0110 0001b
T = 74h = 0111 0100b

...and SSE it, you can get 16 bytes/clock. So even the best C solution there is ~32x slower than what the CPU can do.