Data Cube Systems

Intel’s plan to improve the PC’s performance and power efficiency by putting a chunk of flash memory cache on motherboards was previewed at the 2006 IDF under the codename “Robson,” and when it was launched the next year as “Turbo Memory” it never took off. Now the company has a followup to Turbo Memory, codenamed “Braidwood,” that will debut in the new 5-series chipsets for Nehalem. Braidwood’s ability to cache frequently used data, like application binaries and open files, will significantly decrease boot and load times, and provide users with a more responsive computing experience.

Why didn’t Turbo Memory take off, and why will Braidwood be any different? And is a recent, widely cited report by Objective Analysis correct in asserting that Braidwood will nullify any advantages that SSDs offer, thereby killing the latter?

From Robson to Braidwood

Turbo Memory was a good idea in theory, but it was a bit ahead of its time. The Robson flash module had to use the PCIe bus via a bridge chip, and since it was situated as far from main memory and the CPU as the hard drive, it didn’t confer a substantial average latency advantage over cache-equipped hard drives for most usage scenarios. This reality, plus Microsoft’s general lack of interest in developing software support for Robson beyond the initial lackluster Readyboost implementation, ultimately spelled doom for the technology.

But the idea of somehow wedging a large pool of flash memory into the giant latency gap in the storage hierarchy that exists between DRAM and the hard disk is still a solid one for reasons of performance and power, so Intel is having another go at it with Braidwood. Instead of relying on the PCIe bus, Braidwood will put its cache modules on a dedicated ONFi2 bus that hangs directly off the main hub. This next-gen, high-bandwidth flash interface format from Intel, which we’ve described in a previous article, is much more appropriate for hosting the flash pool than Intel’s previous bridged PCIe solution.

Braidwood will still sit the same number of hops away from DRAM and the CPU as the hard disk, so it will have to rely on a combination of the ONFi interface and latest flash modules’ much higher read/write speeds to be a useful addition to the storage hierarchy. It’s also the case that at rumored sizes of 4, 16, and 32GB, the Braidwood pool will be large enough to host a very high percentage of a system’s most-used data, which means that HDD accesses will be much rarer than under Robson.

As for the idea of Braidwood making SSDs irrelevant, the report leaves us unconvinced. It’s likely that Braidwood will cannibalize some amount of potential SSD sales, but SSDs have their own advantages (reliability, speed, power) and the main barrier to their wider adoption is their persistent price premium. What’s more likely is that the reverse will happen, and SSDs with a dedicated ONFi interface will replace Braidwood eventually. After all, it’s not clear that the majority of users are going to want to pay for 16GB of flash that they can’t directly control like a normal file volume. Besides, we just need to stop hobbling SSD with drivers and interfaces that were designed for rotating magnetic storage, and give the technology its own bus and its own dedicated role in OS memory management.

As for when Braidwood will launch, that’s still up in the air. We contacted Intel and were told, “Braidwood schedules are under assessment, we have no announcements at this time.” Recent rumors have it delayed until 2010, which would make sense in light of other rumors that Intel is developing all of the drivers and other software to make it work. Whatever the case may be, at some point the 5 series will see the addition of this technology.

The 5-series as a milestone

Tuesday’s launch of Intel’s 5-series chipset and desktop Nehalem represents the most important change in Intel’s desktop PC architecture in over a decade, because the memory controller will finally make the jump onto the processor die; in the Havendale Nehalem variant, the IGP will jump onto the die, as well. The fact that the main processor die will go from being a multicore CPU to a full-blown SoC—complete with an I/O interface in the form of PCIe links—makes the 5 series the perfect time to tackle the long-overdue task of rethinking PC system architecture based on a new storage hierarchy that presumes the availability of cheap flash memory.

In the case of Havendale, the rethink is especially apt, because with this platform, both the CPU and the GPU—the two main consumers of bandwidth in the system—are now together and are only two hops (SATA, then DMI) away from the main storage pool. This reduction of hops from three to two would, by itself, be an improvement, but adding the Braidwood cache to the mix helps even more. Most of the read/write traffic can now happen between solid state parts (DRAM and flash) via the on-die memory interface, with the magnetic disk spinning up very infrequently.

Finally, no discussion of the 5-series would be complete without noting that AMD got there first. AMD has had an on-die northbridge (and a real system interconnect, HyperTransport) since 2003, so Intel is super late to this particular party. But better late than never.

Advanced Micro Devices has launched a low-power version of its six-core Opteron processor in time for VMworld, a key virtualization show that opens on Monday. 

The six-core AMD Opteron EE consumes 40 watts, and is designed for 2P servers, among the most popular in the virtualized server space. The chip will cost $989, and will begin shipping on Monday.

To maintain the same thermal envelope as the previous generation chip, the Opteron 2419 EE runs at 1.8 GHz, versus the 2.0+ GHz clock speeds of the “Shanghai” Opteron generation. AMD claims that the 2419 EE offers up to a third more performance than the 2377 EE, a four-core chip whose cores were clocked at 2.3 GHz, which also ran at a 40-watt thermal envelope.

The new six-core chip also includes the AMD-V virtualization technology, as AMD’s AMD-P power management mechanisms. VMworld, the show run by virtualization company VMware, begins Monday in San Francisco.

AMD also estimated that the power consumption for a fully populated 42U rack would be 9.2 KW using the six-core Opteron 2425 HE, a 55-W part. Replacing those chips with the 2419 EE would require 7.5 KW, about an 18 percent power savings.

According to IDC data quoted by Brent Kerby, a product manager for the chip, about 82 percent of cloud and Web servers only use about half of their available processor power at any given time. “With more cores, you have more headroom for those peaky times…to support a heavy amount of Web hits, if you will,” Kerby said. “The most concerning area is power consumption, being down in the the 40-watt power band, and not extending above the power threshold.”

The bottom line? More computing power in a given rack (or higher compute density) while maintaining a low 40-watt power band, Kerby said.

The new Opteron chip also uses DDR-2 memory, which AMD claimed could save about $1,000 per server, as opposed to more expensive DDR-3 memory.

MIT researchers claim that an experimental material called graphene may be able to boost the clock speed of computer chips into the 500-GHz to 1,000-GHz range.

According to a report issued by the MIT news office last week, the research findings will be discussed in a paper in the May issue of Electron Device Letters. They also were described last week at the American Physical Society meeting by Tomas Palacios, assistant professor in MIT’s Department of Electrical Engineering and Computer Science (EECS).

Graphene is a form of pure carbon that was identified in 2004. It’s essentially a one-atom-thick honeycomb lattice of carbon. Since the discovery of graphene, researchers at various institutions have been exploring possible uses for the substance. Palacios believes it will play a key role in future electronics.

The scientists at MIT EECS — Palacios; assistant professor Jing Kong; and two of their students, Han Wang and Daniel Nezich — have constructed an experimental graphene chip capable of multiplying electrical signal frequencies.

While frequency multiplication technology is used in current electronics, these systems generate noisy signals and require significant filtering and power, according to the MIT news service. The graphene chip uses only a single transistor and its output is clean, requiring no filtering.

Palacios said the technology could be commercialized in a year or two. The research is being funded by the MIT Institute for Soldier Nanotechnology and by the Interconnect Focus Center program, and is being followed both in the federal government and by private-sector chip companies.

Looking ahead, MIT’s researchers are trying to develop a way to grow graphene wafers suitable for use in electronic manufacturing.

Both financial and environmental incentives should compel organizations to embrace PC power management.

Asustek Computer Inc. unveiled a new laptop at the CeBIT show in Hannover, Germany, today that comes equipped with a 1TB solid-state disk (SSD) drive, a 16-in. high-definition display, a Blu-ray drive and leather-covered panel rests.

The Asus Lamborghini VX5 laptop comes with an LCD cover designed to remind users of the Lamborghini Reventon sports car’s aluminum-alloy fuselage.

Its piano-painted mirror surface is also supposed to mimic the car’s finish. The notebook comes with a 1TB SSD from pureSilicon Inc., which launched the compact flash-memory drive in January.

The pureSilicon SSD boasts a data-transfer burst speed of 300MB/sec.

a sustained read speed of 240MB/sec. and a sustained write speed of 215MB/sec.

The Lamborghini VX5 will also come with an Intel Core 2 Quad CPU and 4GB of RAM. “It features a ‘twin turbo’ mode that users can utilize to accelerate CPU and GPU performance via a speed key,” Asus said.

The notebook also has an illuminated “chiclet” keyboard that automatically lights up in low light conditions.

The laptop’s display is a 16-in. “full HD” screen — 1080p, or 1920 by 1080 pixels — along with a dedicated Nvidia GeForce GT 130M graphics chip with 1GB of GDDR 3 video RAM.

The laptop’s Blu-ray drive and the onboard HDMI socket allow output to an HDTV for watching movies.

Asus has not yet set a release date or price for the new laptop.