Question about Opteron pairs

I know with Xeons you want to (or have to) use 2 procs of the same stepping, but is there even such a thing with Opterons? Will ANY 2 246's, for instance, work together?

With any dually, you don't need the same stepping chips, AT STOCK. If you are overclocking, 2 chips with the same stepping have a greater chance of overclocking the same amount. I think you may be confusing the model number (ie: Opteron 246) with the actual stepping, like IQYHA (I dunno A64 steppings...). As long as they are the same model, they are identical and will work together. As in, you couldn't mix a 246 with a 245 model.

I remember reading in a thread that someone apparently tried 2 2.4 Xeons of different steppings (D0 and M0) on some motherboard which said they weren't the same. I haven't really seem much discussion about the steppings of Opterons (compared to that of Xeons) so I thought maybe AMD doesn't make different steppings with Opterons...but I guess that would be wrong.

So now my question is, which steppings are the best?

Some 246s have different Vcore requirements (HEs) so you have to make sure the Vcores match. You can probably get around that with a u-wire socket mod though.

BTW, there are different stepping for Opterons, e.g., B3, C0, CG, E4, etc, in addition to low voltage versions such as the HE, which is actually a CG stepping. This is not a complete list, so no need to correct me.