SSVD on very large and sparse matrices

[Ron Ayoub]

I'm doing some up front research on implementing LSI and choice of tools. I 
understand Mahout provide an out-of-core implementation of Stochastic SVD. On 
the web site it use the words 'reasonable size problems'. Would a spare matrix 
1,000,000 * 1,000,000 having some 250,000,000 nonzero entries be out of the 
question. If so, what tools out there can do that. For instance, ARPACK. 
Regardless, how does Mahout SSVD compare to ARPACK. These seems to be the 
options out there that I have found. Thanks.