Rambus

Rambus Incorporated (NASDAQ: RMBS) (founded 1990) is a provider of high-speed interface technology, most notably their Rambus Direct RAM memory technology, which was intended to replace SDRAM as the standard memory used in computers.

Licensing

As a company with no chip production facilites of its own, Rambus conduct business by filing patents, and then licensing technologies. For example, Nintendo licensed RAMBUS memory for the N64 console. However, the most famous agreement was with Intel Corporation in 1996, under which Intel became obligated to use RDRAM as the primary memory technology of all Intel platforms until 2002.

In exchange for these somewhat restrictive terms, Intel was given a cut of the royalties, which Intel management anticipated would be a lucrative source of high margin revenue. In reality the RAMBUS standard did not prove to be popular, and motherboard manufacturers simply bought chipsets from VIA Technologies, which did support SDRAM technology. Ironically in this manner, one of the most enduring achievements of RAMBUS, was to facilitate the rise of VIA Technologies.

Technology

The first PC motherboards with support for RDRAM debuted in 1999. They supported PC800 RDRAM, which operated at 800 MHz and delivered 1600 MB/s of bandwidth over a 16 bit bus using a 184 pin RIMM form factor. This was significantly faster than the previous standard, PC133 SDRAM, which operated at 133 Mhz and delivered 1066 MB/s of bandwidth over a 64 bit bus using a 168 pin DIMM form factor.

Some downsides of RDRAM technology, however, included significantly increased latency, heat output, manufacturing complexity, and cost. PC800 RDRAM operated with a latency of 45ns, compared to only 7.5ns for PC133 SDRAM. RDRAM memory chips also put out significantly more heat than SDRAM chips, necessitating heatsinks on all RIMM devices. RDRAM also includes a memory controller on each memory chip, significantly increasing manufacturing complexity compared to SDRAM, which used a single memory controller located on the northbridge chipset. RDRAM was also two to three times the price of PC133 SDRAM due to a combination of high manufacturing costs and high license fees. DDR SDRAM, introduced in 2000, operated at an effective clockspeed of 266 MHz and delivered 2100 MB/s over a 64-bit bus using a 184 pin DIMM form factor.

With the introduction of the i850 chipset, Intel added support for dual-channel PC800 RDRAM, doubling bandwidth to 3200 MB/s by increasing the bus width to 32 bit. This was followed in 2002 by the i850E chipset, which introduced PC1066 RDRAM, increasing total dual-channel bandwidth to 4200 MB/s. Also in 2002, Intel released the E7205 Granitebay chipset, which introduced dual-channel DDR support for a total bandwidth of 4200 MB/s, but at a much lower latency than competing RDRAM. In 2003, Intel released the i875P chipset, and along with it dual-channel DDR400. With a total bandwidth of 6400 MB/s, it marked the end of RDRAM as a technology with competitive performance.

Lawsuits

In the early 1990s, Rambus was invited to join the Joint Electron Device Engineering Council in return for releasing a number of technologies into the public domain, on the condition that they sign Non-disclosure agreements with the other JEDEC members and disclose any patents they had relating to DRAM technology. They did so, and participated in the JEDEC until 1995, when they withdrew after the JEDEC refused to accept RDRAM as an official standard. After leaving the JEDEC, Rambus amended a number of open patent applications to include technologies relating to SDRAM and DDR that had been discussed in the JEDEC while Rambus was a member. Rambus claimed to be the originator of these technologies.

In 2000, Rambus began filing lawsuits against the largest memory manufacturers, claiming that they owned SDRAM and DDR technology. Seven manufacturers, including Samsung, quickly settled with Rambus and agreed to pay royalties on SDRAM and DDR memory. When Rambus sued Infineon, however, Micron and Hynix joined forces with Infineon to fight the lawsuit, countersuing with claims of fraud. This trio of memory manufacturers became known as "The Three Amigos". In May of 2001, Rambus was found guilty of fraud for having claimed that they owned SDRAM and DDR technology, and all infringement claims against memory manufacturers were dismissed. In May of 2002, the United Stated Federal Trade Commission filed charges against Rambus for antitrust violations. Recently Rambus has filed four more lawsuits against memory chip makers claiming that DDR 2, GDDR 2 and GDDR 3 chips contain Rambus technology.

External links

• Rambus Inc.
• Intel Corp.
• Rambus' Rambling Lawsuits.
• FTC Issues Complaint Against Rambus, Inc.
• Rambus' Litigious Path.
• New lawsuits seek to bust Rambus.
• Rambus Faces Fundamental Threat .
• Rambus is back with a brand new lawsuit in hand.
• Rambus files new memory suit.
• Rambus sues four for GDDR 'infringement'.
• Rambus poo-poos Hynix Euro patent victory claim.
• Rambus income slides despite revenue gains.
• Infineon accuses Rambus of 'litigation misconduct.
• Rambus CEO eager to move beyond the courtroom.