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News Glance: The Essential Commentary on the Week’s Hottest News (page 7)

Category: Editorial

by Anton Shilov

[ 07/09/2004 | 04:52 PM ]

Kentron Wants End-Users to Choose QBM

Kentron does it again: it speaks about advantages its Quad Band Memory brings to users without providing anything real. First announced on May 28, 2000, the technology has not made it to the market in 4 years, moreover, current comments from Kentron imply that chipset makers are unlikely to support its memory technology in the future.

Quad Band DRAM allows to double memory sub-system’s bandwidth using the widely-spread DDR SDRAM chips. Modules, that correspond to QBM standard make use of ordinary memory chips but add a special PLL (switch) to allow half of the chips to work at 90 degrees displaced frequency, hence, data becomes available almost two times more frequently compared to ordinary modules. Basically, such way of functioning resembles a 128-bit memory module with a pair of 64-bit channels that switch, in turns, one over another.

Quad Band memory module

The peak bandwidth of such RAM system can be up to 4.2GB/s when using ordinary 266MHz memory chips (PC2100), the main advantage of this technology is its presumable cost-efficiency. Since QBM technology does not require any additional signaling, QBM memory modules can maintain compatibility with widely available memory slots, such as those used for DDR or DDR2 memory. Still, current version of QBM requires chipset support, which, in the past, lead to Kentron’s flop in the market as VIA Technologies, the only maker of chipsets who had planned to support QBM, dropped the idea of Quad Band Memory-supporting core-logic.

In a recent interview representatives for Kentron Technology indicated plans to release QBM-2 specification along with memory modules featuring DDR2 chips in 1H 2005. This time Kentron does not count on third-party chipset makers, but intends to install a special chip direct onto memory modules.

“Having extra logic to implement into the memory controller limited us to the memory controllers that supported you, which was one. In order to have broad acceptability, we want the user to make the decision rather than the chipset product group,” a Kentron’s spokesman said.

Additional chips and logic have never made products more affordable and from an end-user standpoint it is always more efficient when chipset’s North Bridge supports variety of memory module types, while memory modules themselves carry on memory chips only with no additional logic. However, Kentron believes that additional bandwidth its memory modules will be able to provide will make the chips more valuable than competing products.

The main idea of QBM is providing peak bandwidth of dual-channel memory sub-system by single-channel QBM memory sub-system or providing the same bandwidth using two memory modules featuring lower-speed components. Both cases seem to have their cost advantages, but any new technology has to have something more than just a tiny pricing benefit. Customers should see what they would get with the addition of higher-speed, more expensive and unknown memory modules. Furthermore, under the “customer” term we should consider a system integrator or an actual end-user, two types of clients who are pretty slow when it comes to a new technology that is not pushed in by loads of hardware companies.

Dual-channel QBM DDR2 667MHz sub-system can provide 21.3GB/s bandwidth, a lot more than today’s and tomorrow’s central processing units require, which will hardly make QBM popular in PC segment. Another target market for the QBM memory is communication equipment and consoles, both usually require extreme bandwidth. Rambus succeeds in pushing its memory technologies into comms and consoles, whether Kentron succeeds in this (maybe with Xbox 2?) remains to be seen.