Can a Core 2 Quad Q6700 replace a Pentium D 945?

Yes, a Core 2 Quad Q6700 can replace a Pentium D 945, provided that the motherboard supports the Core 2 Quad processor. The Q6700 offers better performance due to its quad-core architecture and higher clock speeds compared to the dual-core Pentium D 945. Ensure that the motherboard's socket and chipset are compatible with the Q6700 for a successful upgrade.