BX Board Multi Dimm Configuration Question

[Joe]

I apologize if this question has been asked before, but what is the
technically preferred or best configuration when using only 2 similar
generic 256mb dual-sided unregistered, non-buffered, non-ECC low density
dimms (eight 16x8 chips on each side) for my AT-Form (non-ATX) Gigabyte
GA-6BA BX chipset mobo which has 4 memory slots?

I've heard some rumors that some 4 slot BX chipset mobos using only two
modules run best with slots 1 and 3 or 2 and 4 ........ but not with slots 1
and 2, or slots 3 and 4, when using only 2 unregistered non-buffered dimms?

I presently have one module inserted slot 1 (nearest the PIII processor and
BX chipset) and one inserted in slot 3 running at 100MHz FSB speed (no
overclocking).

They both show up properly as 256mb each (for a total of 512mb) on my
Windows ME system. They are generic PC133 CL3 modules (also rated to CL2 at
PC100 according to Si Soft's Sandra). I use the latest f1g bios for my
GA-6BA Rev 2.5 board.

I've used MemTest86 Ver. 2.9 on the them for over 24 hours non-stop several
times and they always test clean (both separately and together) with no
errors reported at CAS2 speed, so I presume they are good modules and my
slot 1 and 3 configuration is reasonable. I have no random instability or
apparent memory related issues with my PIII Slot 1 system.

Also, I've set the bios to CAS2 rather than Auto, because I've heard that
some eproms on generic memory modules do not report settings properly ......
I've have no trouble with these two 256mb modules so far in slots 1 and 3.

But should I have them in adjacent slots 1 and 2, or 3 and 4 instead??
Should I use set them at CAS3 instead of CAS2 even though I'm only running
at 100MHz FSB.

Any thoughts or comments would be greatly appreciated .... Thanks.