Computing SVD Of "Large Sparse Data"

[Eshwaran Vijaya Kumar]

Hello all,  
  We are trying to build a clustering system which will have an SVD component. 
I believe Mahout has two SVD solvers: DistributedLanczosSolver and SSVD. Could 
someone give me some tips on which would be a better choice of a solver given 
that the size of the data will be roughly 100 million rows with each row having 
roughly 50 K dimensions (100 million X 50000 ). We will be working with text 
data so the resultant matrix should be relatively sparse to begin with. 

Thanks
Eshwaran