Types of Ram?

My motherboard, K7 Triton GA-7N400-L supports and is presently running in dual channel mode with two 256MB memory modules in DIMM 1 & DIMM3. Processor is Athlon Thunderbird 1400 and operating system is ME. The motherboard book says that if I have 4 memory modules they must be as follows: DS/SS in DIMM 1,
DS/SS in DIMM2, SS in DIMM 3 and SS in DIMM 4. The memory I have has chips on both side of each piece. Is that what DS means and if so I would need 2 SS chips to put in Dimm3 & Dimm 4 to add memory and still run in dual channel mode?
Can someone tell me what the DS and SS means?

 

I appreciate the help. According to the manual, I can still operate in dual channel mode if I put DS memory in DIMM 1,2 & 3 and all can be DS/SS. It doesn't say if they have to be the same size. I am thinking of adding a 512 MB stick and don't know whether to just put it in DIMM 2 which is now empty or what? Should any DS Ram work?

I see RAM advertised on Ebay as low density. Is this desirable?

 

Okay, I bought a 512MB stick of Kingston DDR400 which is "backwards compatible with 2100. I have two 256 MB sticks of 2100 Ram.
When I installed the RAM, the new correct total showed on the screen and said it was in dual channel mode during boot, but after the initial appearance of the Windows ME screen, the screen went black and I had to reboot and start Windows in safe mode. Display goes back to 16 colors,640 x 480 in safe mode. When I try to restart in normal mode, same thing happens. I took the new 512 MB stick out and computer is working normally.

Can someone help me?

 

All sticks have to be same size manufactuer and very similar models so your best bet is to buy 2 more same ram sticks then have 3x512 1.5gb

 

According to the book on the mother board, "memory size can vary between sockets" and "The Bios automatically detects memory type and size", although it also says" if memories are inserted on DIMM3 and DIMM4 at the same time, they must be exactly alike in device, type, size, and single side. This is essential to let the system boot up correctly." I am not using DIMM 4 so I don't see why my setup won't work. Also, I don't know how significant it is but during boot up, the added memory is shown in the total on screen. Windows seems to have the problem with it. It will boot in safe mode and the memory is shown in the Control Panel/System/Performance.

Sometime in the past, I seem to remember reading something about Windows ME having a problem with amounts of Ram over 512 MB and it having something to do with screen resolution but I can't find anything about it now. Do you think that Gigabyte (motherboard manufacturer) might help me?)