Bolc,they are totally diferent on ram oc and latencies.
The difference in max frexuency for the x48 chipset will be given by the nbb,on some it's better. Cold will influence this aspect .
Pl6-7 are for 2000 mhz +.
Some psc work really good on rex,6-9-6 PL 6 over 2040 mhz.
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