Different size sticks same speed?

nemesis4895

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May 16, 2011
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I currently have the Asus P8H67-M Pro motherboard with 4 GB (2 x 2GB) of Crucial RAM, 1333 Mhz, CAS 9. I just ordered two more sticks of RAM which are 4 GB per stick, 1333 MHz, CAS 7. Will any problems occur if these two sets are in the motherboard together?
 

r3xx3r

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Aug 31, 2009
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im running 8GB (2x4GB) and 4GB (2x2GB) of the same exact ram with the same CAS and it runs fine. you might be fine if you set the CAS timings manually to the higher number (CAS 9) but you could have issues.