Dual RAM issue

[c00lman]

Guys this is the spec of my PC:

Motherboard: MSI MS-7093

RAM:
Memory Installed = 512 MB (2 x 256)
Maximum allowed = 4 GB* (4 x 1GB) requires the replacement of the installed 256 MB DIMMs

*Actual available memory may be less*
Speed supported = PC3200 MB/sec
Type = 184 pin, DDR SDRAM
DIMM slots = Four (4)
Open DIMM slots = Two

ok as u see, i have 4 channels. 2 occupied by 2x256MB (PC3200) HYNIX
I just bought an extra SAMSUNG 512MB (PC3200) [so shuld have 1 gb ram]
installed..it only detected a max of 768MB.
i tried ALL sorts of combinations

1st 2 channels are blue
2nd 2 channels are black.

is it true they should be ONLY in pairs?
therefore, i shuld get rid of my 2x256MB and get another 1x512MB?

 

[Tedster]

depends on the board. In general you want to install in pairs. Some boards will allow dual or multi channel, others won't. When all else fails read the manual.

read the ram installing guide in the guides forum.