Despite an oversupply that has driven sharp price erosion over the past year, DRAM manufacturers continue to pursue the latest technological advances to gain an edge on competitors. Leading vendors are diversifying their product lines, driving down operating costs and improving production efficiencies to mitigate ongoing problems in the mainstream DRAM industry.
Helping maintain bit demand is the increasing adoption of more complex operating systems, primarily Microsoft's Vista, and an ongoing transition from desktop to notebooks. More often than not, these new systems require not only higher densities of main memory, but discrete memory and GPUs to deliver adequate performance. In many cases DRAM manufacturers achieve these goals with the introduction of a new generation of DDR3 devices designed to supplant older-generation DDR2 memories. Analysts at market research firm IDC expect DDR3 memories to account for 72 percent of the total DRAM market by 2011.
|DDR3 will account for 72% of DRAM sales by 2011, analysts say |
Tokyo-based Elipda Memory, for example, uses an optimized copper interconnect process and new circuit technology to deliver the industry's first DDR3 SDRAM capable of operating at up to 2.5 Gbits/s. The 1-Gbit device is available at the industry standard 1.5 V. But the company is also offering a 1-Gbit DDR3 device capable of operating at 1.8 Gbits/s at 1.2 V. The copper interconnects offer superior transmission characteristics over aluminum alternatives.
Energy costs key
The recent spike in energy costs has designers of both servers and desktops refocusing their efforts to reduce power consumption in main system memory. With memory consuming as much as 15 percent of all power in data center server designs—and that number expected to rise as new apps drive memory requirements up—manufacturers are putting renewed priority on developing more power-efficient parts. Micron Technology, for example, has expanded its energy-efficient Aspen product portfolio with more efficient low-voltage DDR2 and DDR3 products.
Higher energy efficiency is especially important in data centers that run 24/7, said Brian Shirley, vice president of Micron's Memory Group. "Until recently, IT and data center managers primarily looked at ways to reduce power consumption with energy-efficient processors and power supplies, but they hadn't looked at the additional savings they can achieve with low-voltage memory."
Earlier this year Micron announced 2-Gbit-based DDR2 modules operating at 1.5 V, and 1-Gbit-based DDR3 modules operating at 1.35 V. The new 8-Gbyte DDR2 modules reduce power consumption by up to 58 percent compared with conventional 1-Gbit-based 1.8-V DDR2 modules. The new DDR3 server modules, available in densities up to 4 Gbytes, use 21 percent less power than standard 1.5-V, 1-Gbit-based DDR3 modules. To enable better systems and graphics performance, the new DDR3 modules support data rates up to 1333 Mbits/sec.
Lower power consumption is also a natural focus in embedded and mobile applications. There, memory-intensive apps such as data-connected 3G phones, personal media players and GPS systems are driving the migration from older Low Power DDR1 (LPDDR1) ICs to a new generation of LPDDR2 devices. Both Elpida and Korea's Hynix Semiconductor announced LPDDR2 ICs within the past year, for example. The 1-Gbit Hynix part, fabricated in a new 66-nm process, supports a maximum operating speed of 800 Mbits/s off a 1.2-V supply. It comes in a compact 9 mm x 12 mm form factor.
Meanwhile, DRAM manufacturers continue to push the process envelope to higher densities. Using a 50-nm process, industry leader Samsung Semiconductor recently announced the industry's smallest 2-Gbit DDR3 devices. The tiny form factor lets designers configure up to 8 Gbytes of memory chips for RIMMs, and up to 4 Gbytes for SODIMMs and UDIMMs without stacking. Using dual-die packages, 2-Gbit DDR3 RIMMs can reach densities of 16 Gbytes. The new 2-Gbit IC also consumes up to 40 percent less power than dual-chip solutions using two 1-Gbyte memory devices. Data rates reach up to 1.3 Gbits/s at 1.5 V or 1.35 V. p
John H. Mayer is a freelance writer based in Belmont, Mass.