Mobile apps bring momentum to DRAMs

As the wider DRAM market sputters along, the mobile DRAM segment is firing on all cylinders, scrambling to keep pace with the volume demand and bandwidth requirements of the fast-moving markets it serves.

Mobile DRAMs are specialized DRAMs that incorporate low-power features. Vendors of the devices, such as Elpida, Hynix, Micron and Samsung, face inventory shortfalls as OEMs of hot-selling smartphones and tablets race through the stock now on the shelves. Elpida Memory Inc. alone is shifting much of its production from PC DRAM to mobile DRAM to meet demand from Apple Inc.’s iPad 2, sources said.

At the same time, mobile market bandwidth requirements are lapping the capabilities of current-generation mobile DRAM technology, forcing a lane change to next-gen standards.

“The requirements for bandwidth are going through the roof,” said Jim Venable, president of the Serial Port Memory Technology (SPMT) consortium, a group that is devising a next-generation memory technology. Low-power double-data-rate 2 (LPDDR2) mobile DRAM, the latest and fastest mobile DRAM technology, “is already seeing the end of its life,” Venable said.

Various factions have rolled out rival next-gen mobile DRAM technologies in response to the urgent need for more bandwidth. The contenders are LPDDR3, LPDDR4, the Mobile Industry Processor Interface Alliance’s M-PHY, Rambus’ Mobile XDR, Silicon Image’s SPMT and wide I/O. Samsung and others are backing wide I/O; Micron is pushing LPDDR3.

Mueez Deen, director of mobile DRAM at Samsung Semiconductor Inc., said it’s still too early to predict a technology winner, but he noted there is only room for “one new technology” or a “maximum of two” for mainstream devices in the future.

Bandwidth concerns cry out for new technology. In one example, LG Electronics recently rolled out the Optimus 3D, a 4G smartphone that features a “glasses-free” stereoscopic 3-D display, a dual-camera and HD video.

The LG smartphone is build around Texas Instruments Inc.’s OMAP 4 dual-core applications processor as well as mobile DRAMs based on LPDDR2. Apple’s iPad 2 also uses LPDDR2 mobile DRAM.

Some believe that LPDDR2 is obsolete even before the parts ramp in volumes. Mobile DRAM based on LPDDR2 technology has a maximum of 8.5 Gbytes/second of peak data throughput at an estimated power consumption of 360 mW. By 2013 at the latest, the industry is shooting for data rates of “12.8 Gbytes/s at 500 mW,” said Herb Gebhart, vice president of strategic development at Rambus Inc.

Brian Carlson, product line manager for TI’s OMAP 5 applications processor, said mobile DRAM may need to run at 25.6 Gbytes/s in the future. The challenge is to devise a faster technology, while also reducing the chip size and power consumption to extend battery life, he said.

The stakes are high in mobile memory. Before the onslaught of snazzy smartphones and tablets, mobile DRAM was considered the “sleepy backwater” in the memory market, said Mike Howard, an analyst at IHS iSuppli. Now, thanks to smartphones and tablets, the mobile DRAM sector is expected to grow by 71 percent in 2011, Howard said.

Mobile DRAM is outpacing the overall DRAM business. Amid a slump in PCs, the DRAM market will total $35.5 billion in 2011, down 11.8 percent from $40.3 billion in 2010, according to IHS.

The average DRAM content in smartphones and tablets is increasing from 512 Mbytes today to 1 Gbyte in the future; in contrast, PC DRAM content averages 3.4 to 3.5 Gbytes, said Hans Mosesmann, an analyst with Raymond James & Associates Inc.

A mobile DRAM costs two to four times more than a PC DRAM because of mobile apps’ stringent size and power demands. The mobile DRAM business is based on a build-to-order model, with pricing driven by cost reductions rather than the fluctuations of supply and demand, as in commodity DRAM, IHS’ Howard said.

But as competition mounts, the predictable supply/demand model is cracking. Supply and demand are in “balance right now, moving into oversupply in the second quarter,” Howard said. “We see tighter supply in the second half.”