Optiplex 740: Dual-channel memory?? bios

gang I'm rehabbing an old dell optiplex 740. this is the minitower chassis of that model. it has amd athlon 2.1ghz and, of all things, a NVIDIA chipset.
the superficial specs claim that the memory controller manages Dual-Channel memory, and the physical would suggest that: it has four DDR2 slots that are color coded 2-black, 2-white.
ordinarily one would assume that the colors represent channels 0 and 1.
however, no matter how I populate the four slots, the bios shows Single Channel mode [happens to be a fairly informative bios].

what's up with this? is it crippled? is the bios wrong? is the mode under OS control [i sure wouldn't think so].

I be clueless at this point.
thx for any help

 

You need to populate both channel slots for it to show "dual channel mode", and the sticks need to match exactly. That means timings, and frequency.

 

did that before posting. bios showed single

best I can tell from the out of date user manual/guide, their color coding is backward to most every other system produced. the two white slots are on two channels [one each] and must be matched. ditto the two black. at least that is the theory expressed in the user guide.

 

But if you put 4 identical sticks in the 4 slots, it would not matter which stick went where - it should still show up as being in dual channel mode - if all was working correctly.

So I think the memory controller is messed up. I would reset the BIOS. I would also check for BIOS updates.

No, because this is done at the hardware level during boot BEFORE the boot drive (and thus OS) is ever touched.

 

i got it figure out. i have 2 matches, 2 pairs. the color coding is just backwards from what many other have used: they need to match per bank, so slots 1-2 must match, slots 3-4 must match. [they number at 1, not zero].
works.

 

Great! Glad you got it sorted out and thanks for the followup.