I just posted a reply to a similar question, so here we go again:
Yes, the Asus A7V133 supports 4-way memory interleaving. Set your system for "Optimal" in your BIOS and you're all set.
If it wasn't working, trust me, you'd notice it from the first time you ran your system. Without it, it's like running defrag on a hard drive in PIO mode, the system literally "chokes" and stutters like mad.
If you set the BIOS for "Normal", 4-way interleaving is disabled for compatibility and stability reasons.
Very bad. EVIL. So leave it (or set it) to "Optimal" and enjoy.
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