Adding two more memory sticks same speed?

[gondwana]

Hello, i have the G.SKILL Ripjaws X Series 4GB DDR3 1600 Cas latency 6-8-6-24 installed. Can i buy one more set and run 8GB with the same speed and latency?
or will it downgrade the performance? This is dual channel memory.







2500k 1155
GTX 570
Asus P8Z68-V PRO 1155
GSKILL DDR3 1600 4GB
Win7 64 bit
100wt power supply

[GSKILL TECH]

If the two kits can work together, then the same memory spec should be capable.

Thank you
GSKILL TECH