You may need at least 1GB of RAM to get Vista working properly but thanks to new NEC technology, it would be long until your PC comes laden with 10GB without the need to add extra slots.

NEC Electronics, Elpida Memory and Oki Electric have developed a highly compact memory die stacking approach where a 450 micrometre-high stack can contain 8 memory chips and one controller chip leading to a 1 terabit capacity stack.

Each memory chip has more than 1,000 connectors on the top and bottom surfaces with polysilicon electrode connectors running right through the chip. Each chip is connected to the next by myriad "microbumps" placed 50 micrometres (µm) apart. The individual chips are extremely thin, at just 50 micrometres thick.

This compactness means cell phones and other portable devices will have enough RAM to run high-definition video and other 3D graphics applications. It also means that PCs could look forward to having 10GB or more of RAM in the future.

As we know from Microsoft's Vista, PCs need more memory. Memory suppliers like are responding. The demand for cell phones and other portable devices to have ever higher multimedia capabilities means that their memory needs are growing too. On top of this, memory speeds need to be higher and power consumption lower. This makes memory module packaging more difficult.

Manufacturers can pack memory chips together in one of two ways: SiP (system-in-package); or SoC (system-on-chip). A SiP approach has memory chips stacked vertically with interposed separators with bonded wires used for connectivity. A SoC approach stacks memory dies onto one chip but space constraints limit the stack's capacity. The SiP method has chip numbers limited by the wire bonding which also creates impedance issues and limits the number of pins that can be connected to the processor.

The NEC, Elpida and Oki 3D stack means these SiP disadvantages go away. It will enable smaller form factors, faster operating speeds and lower power consumption in the next generation of mobile devices. The low stack height means mobile phones, portable games players and the like will have enough RAM to run high-definition video and 3D graphics applications.

Coincidentally Samsung has demonstrated a 1TB flash memory chip at the 2006 International Electron Devices Meeting (IEDM) last week. Its OneDRAM chip uses some of the new Fusion 3D technology.