indentify sdram voltage and Ns?

I have purchased via ebay 3 sticks of sdram. All 3 sticks are NEC 256mb PC133 32*4. -I purchased one from a source with good documentation it is noted as NEC 3.3v 7/7.5ns.- The other two have limited documentation I do not have the specs of the voltage or the ns. I do have documentation that indicates they are both 256 MB NEC 133MHz 32*4.NEC site lists thiese as no longer in production. How nice for them! Please if you can advise I would most appreciate it. Q: How can I identify the voltageand the ns?