I think the title speaks for itself.
I didnt have time to really read this yet, but it looks like it may be helpful.
It is written for the 680I but after owning a 650I I dont believe there is much difference.

680I/650I Ram Timing Guide

Messed around with this, wasn't able to get much more bandwidth out of it yet, but will keep trying.

I read a bit of it last night. And will put it to the -*test*-('") this weekend. See if it helps.

I think we have virtually the same rig.

Looks that way Depending where you are in Florida we may be neighbors as well LOL.

St. Augustine.

So ... Tarawa ... you really want to quit the Raptor Pit and join up for the wars here, right?

Lil north a Tampa here..... near Weeki Wachee Fl.

Is a signing bonus involved?

Maybe we can talk Merc into it.

Just always remember the minimum timings for tRAS and tRC can be calculated as:

tRAS = tCL + tRCD + tRP

tRC = tRP + tRAS

Going with lower values of tRAS and/or tRC than these calculated values will not result in better performance and probably give worse results or errors (because the memory timing model is violated). That being said, there's no guarantee that you be able to go as low as these minimum values with tRAS (at whatever tCL, tRCD and tRP you've chosen). No matter what you set tRAS to, be sure to set tRC with the formula.

So the moral of the story is:
If you tweak tCL (CAS), tRCD or tRP, be sure to adjust tRAS and tRC.