Ok, let me help to clear this up. First off, there is CAS, then there is CL, which stands for CAS Latency. But all should become clear if you just go into your BIOS, go to the DRAM control under Advance Chipset Features, you will see numerous settings that can be changed. By SPD, this RAM is automatically "seen" as DDR400, and it runs (at least on my FIC AN19E) at 400Mhz. But the default setting for CL is virtually always set to 2.5. I manually change this setting to 2, as well as enabling a Bank Interleave of 4-bank.
Now, here's where the dash numbers come in. There are settings after these called:
Precharge to Active (Trp)
Active to Precharge (Rras)
Active to CMD (Trcd)
as well as other settings. These are what the 2-2-3 are refering to, and there are others like DRAM Command Rate, Write Recovery Time and DRAM tWTR, all of which have settings of 1T, 2T or 3T. The top setting on this menu is "System Performance", with 4 options, Normal, Fast, Turbo and Ultra, which adjusts many of these settings for you.
Oh, for reference, I don't overclock my equipment. I've got 15 or so computers here, if I need more performance I'll gather them into a linux cluster. Or just buy a faster Athlon XP. But if you want to lend me a chip to overclock, I'm more than willing to give it and this RAM a serious testing.