GeCube 9800 Pro memory query - 128bit/256bit

[Monkry]

I bought this model as it stated is was 256bit as opposed to some of the others which are 128bit
The blurb for my 9800 Pro (GC9800PRO-C3)

"Supports 128MB DDR with 256-bit memory interface delivers the bandwidth for real time 3D graphics and barrier free performance @338Mhz clock speed."

The chips on the board are
Samsung K4D263238E-GC2A 128 MBit 2.8 ns uBGA 144

Is it really 256bit?
What's the correlation between 256bit & 128Mbit?

[bim27142]

128MB is the video ram, 256bit is the bus interface(data link) between the VPU and the memory subsystem of the video card...you can use ATITool to verify the bus interface width...bus interface width by the way can be easily manipulated by video card manufacturers that's why there are a lot of variants in every GPU's out there(i.e. 128MB-64bit/128MB-128bit etc...)...