Where is the delay?
If it is from pushing the power button to seeing the grey screen, then I would say that it is likely the additional time needed to check the RAM. If it is between the spinning grey thing and the login screen (or desktop if you use autologin) I would definitely take a moment to boot off the CD and check the RAM. You added 2x the RAM to check on startup, and start-up time roughly doubled. That seems par for the course to me. Its a small trade-off for the added speed everywhere else 🙂
fr0