What exactly i need to mining decred?

[avos1978]

i intend do buy 4 to 6 R9 Nano.

I have this pc:

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CPU
   Intel Core i5 3570K @ 3.40GHz   53 °C
   Ivy Bridge 22nm Technology
RAM
   8,00GB Dual-Channel DDR3 @ 823MHz (9-9-9-24)
Motherboard
   ASUSTeK COMPUTER INC. P8Z77-V LX2 (LGA1155)   34 °C
-------------------------------

My power supply is not good.


Can i use this with 4 R9 Nano? Or with risers can i use more or it is limited to the PCI E slots?

Memory speed is important? I read someware that there are not importance.

Thanks in advance and sorry for my bad english