In today’s world of cut throat competition every other corporation is trying extensively hard to develop technologies better than other. In this race of RAM development, there is extreme competition for introduction of world’s fastest memory for multimedia applications. There are introduction of many fast memory types –

• XDR – XDR is a Rambus-developed technology that moves the data at 8 bits per clock cycle. The data rate in this case is 8GB/sec. The data rate of DD2-400 is 0.8GB/sec, and this shows that XDR is ten times faster than DD2-400.

In fact this is not it but there is still more to come. XDR 512Mbit module with data rate of 12.8GB/sec is poised to enter the market soon. According to Rambus, XDR can support from 3.2 up to 8GHz clock rates.
In XDR the component modules present in the chip uses point-to-point connections to the memory controller, as compared to sharing of multi-drop wire-in case of DDR modules. This is the main reason of XDR being faster than DDR. According to IDC, by next year, global XDR DRAM shipments will exceed 800 million 256Mbit equivalent units. This is looking like a XDR generation after DDR3 DRAM. But there is a valid point that DDR module types are open standards whereas XDR is a Rambus technology proprietary.

• DDR3 – Samsung has claimed the first DDR chip. DDR3, (Double Data Rate 3) Dram has a capacity of 512 MB and can process data at up to 1.06Gbit/s. the main type of DRAM found in most PCs is DDR SDRAM. DRAM is the main memory type used in PCs and servers. Hence it is a known fact that faster the memory, more smoothly the computers will work.

The chip runs at 1.5 volts as compared to 1.8 volts for DDR2, as a result there is less heat generation and also less power requirements, and also enhances the battery life. IDC market research claims that by next year DDR3 will account for more than 65% of the memory market.

• DDR2 – DDR2 offers double speed as that of DDR. This is because DDR has a 2-bit pre-fetch ability whereas the DDR2 has a 4-bit pre-fetch ability. But this not at all means that there is a faster clockspeed though. DDR2 have terminating transistors which ratchet up the signal quality and also eliminate signal noise, placed on the chip itself. There are 240 pins in DDR2 DIMM.

The first DDR2 chips were produced by Samsung in 2001 which ran a lower internal clock speed than equivalent data rate DDR chips. But in this case the 4-bit pre-fetch meant that the effective memory was the same, which reflects that DDR2-400 was as fast as DDR400.this also gives that the data rate is four times the clock rate. Other DDR2 speeds available were 533, 667, 800 and 1200MHz. the DDR2 module has a data rate of 0.8GB/sec.
The DDR2 module capacities are available in following -256Mbit, through 512, 1Gbit and up to 4Gbit.