Hi everyone,

One thing we did this week at MT Marathon was a speed comparison of Joshua 6.1 
(release candidate) with Moses2, which is a ground-up rewrite of Moses designed 
for speed (see the attached paper). Moses2 is 4–6x faster than Moses 
phrase-based, and 100x (!) faster than Moses hiero.

I tested using two moderate-to-large sized datasets that Hieu Hoang (CC'd) 
provided me with: ar-en and ru-en. Timing results are from 10,000 sentences in 
each corpus. The average ar-en sentence length is 7.5, and for ru-en is 28. I 
only ran one test for each language, so there could be some variance if I 
averaged, but I think the results look pretty consistent. The timing is 
end-to-end (including model load times, which Moses2 tends to be a bit faster 

Note also that Joshua does not have lexicalized distortion, while Moses2 does. 
This means the BLEU scores are a bit lower for Joshua: 62.85 versus 63.49. This 
shouldn't really affect runtime, however.

I'm working on the ru-en, but here are the ar-en results:

Some conclusions:

- Hieu has done some bang-up work on the Moses2 rewrite! Joshua is in general 
about 3x slower than Moses2

- We don't have a Moses comparison, but extrapolating from Hieu's paper, it 
seems we might be as fast as or faster than Moses phrase-based decoding, and 
are a ton faster on Hiero. I'm going to send my models to Hieu so he can test 
on his machine, and then we'll have a better feel for this, including how it 
scales on a machine with many more processors.


Reply via email to