As in the cache memory? If you do mean that then no your data won't go, it'll be slower but we've had the cache memory modules on those exact servers fail in life and everything fine, we just replaced them at a later date.
There can be some restrictions on creating NEW arrays on controllers with no cache memory however, but this is an existing array and 'failure' of the cache memory is designed into the controller by design.
That said, please try to avoid using RAID 5, it's essentially dead and considered dangerous in all but a few rare occasions now, I can bore you with why if you like but most IT pro's only use R1/10 or R6/60 these days.