SSD 480 ( firmware R311) on Mac pro Early 2009 trouble

Hi guys : 

I dont se de disk un my power mac, i can upgrade or degrade the firmware ?  what you tink 

I check my system overview and serial show ST31500341as 

there is no R311 for this ssd latest FW is R211. 

the serial number you show is not a sandisk ssd serial number. are you sure you are looking at the correct drive?

if the SSD is not detected you will not be able to update the FW.