What I've found is important is how many of the array elements are Character variables vs. other data types. Character variables seem to consume some resource that other variables do not.

We ran into the same exact problem - we solved it by selecting into a cursor, but since this is in a low-level function that is called many times, the disk write actually slows this down considerably. Array was lightning fast (RAM). For our purposes we needed to use the NOFILTER parameter.

Hope you're not in a performance-sensitive context - if so, select into a cursor ;-)
JP