An Inconvenient Truth: Intel Larrabee story revealed

Things going wrong with Larrabee… in 2007?
We got the first warning flag back in 2006, discussing the matter with people in different groups who were working on Larrabee. We received e-mail with quotes such as "the group in Braunschweig, Germany are seriously a bunch of dip-shits with undeserved chips on their shoulder! It's really a corrupt corporate culture in this office."

Now, if this was one disgruntled engineer, it would be natural for us to discard the information on the claims of bias. But as the time went by, we received bits and pieces with more worrying content. Back in 2007, when Larrabee started to take physical shape, we heard some very worrying statements coming from the people that were coming and going from the team. Most worrisome was the issue with the memory controller - "people involved in designing high performance memory controllers don't even understand the basic concepts of pipelining and they don't understand how to read a memory spec. It is completely ridiculous."

Given the technological changes with the GDDR5 memory, which was selected for Larrabee back then, we knew that the memory controller had to be seriously improved upon compared to controllers that support GDDR3 or GDDR4 memory. As I wrote on my blog ages long time ago, GDDR5 memory is really "a different cookie" than its predecessors. While GDDR3 and GDDR4 were based on the DDR2 memory standard, GDDR5 took a different route and only shares a few similarities with the conventional DDR3 memory.

Additionally, we were constantly meeting with various people in the project Larrabee and projects around Larrabee. Traveling long distance on the same flights as Larrabee engineers also helped a great deal. As engineers were trekking on the traditional USA-Germany-India route, it was interesting hearing their thoughts and concerns. In fact, concerns were commonplace. At that time, Intel was under severe stress from all the investigations going against the company and people that were contracted started to feel uneasy. For instance, "the only thing that silences contractors is the absurd salaries they are paying for the services of being scapegoats for the German Intel Employees - it's something like 150K-200k/year, with German tax evasion services included in the contract deal courtesy of www.internationaltaxsolutions.com." When we received this e-mail, we contacted several [both former and present] contractors at Intel. Upon showing this e-mail to the persons that were in the know, we got confirmation that such deals were in place and were even shown several contracts from the US. Needless to say, the situation got really complicated.

This was all followed by various e-mail and vocal conversations with Intel's engineers that duly believed their baby will see the light of the day. However, any talk about performance was quickly muted, with quotes such as "we have to get our baby out the door. First generation is building ecosystem anyways…" "We need to learn from our mistakes on first generation and create a world beating Gen2". Another source debated that "1st gen is proof of concept. 2nd gen is fixing that proof. 3rd gen is the sh*t."

Naturally, in this stage of development, we were told to expect the chip sometime in early 2010. However, in a conversation that took place at IDF 2007 in San Francisco, a certain Intel executive chit-chatted with several journalists and analysts and was caught saying "In May 2009, we'll ship a processor that will have one dual-core CPU die in 32nm and Larrabee die in 45nm." When we heard that and asked our sources for clarification, there was a chain series of e-mails coming from Larrabee teams and quite frankly, for the first time in years, we saw something that can only be described as a panic. Our olive-branch was that maybe the exec was wrong by a year, but that was also negated to us with a "Theo, that's 2012." statement. That unfortunate statement was one of reasons for numerous leaks about what's going on with Larrabee.

Getting back on Larrabee, at one point in the last 18 months, the engineers saw that the dual 512-bit ring-bus couldn't scale with the number of cores and one of plans was to implement multiple paths, with each ring-bus taking care of 8-16 cores. That was a disastrous idea from day one, and good thing that it didn't take off. But struggle with elementary elements of the chip so late in the process gives you that "this is when the s*** hit the fan" feeling. The 32-core silicon was [and still is] prone to numerous issues, such as cache coherency issues, cores were starving for instructions and overall, Larrabee looked like a mess. Bear in mind, nowhere as near as much of a mess as some GPUs in the past from both ATI and nVidia [starved nVidia NV30 and ATI R600 come to mind].

We were hearing what was going wrong all the time, but whenever we heard that, it was almost 100% coming from ATI or nVidia, so naturally we would dismiss the accusation as typical FUD. But that was nothing for what happened after.

"GPU is dead" and the war with nVidia
In the spring of last year, a certain Intel engineer stated that the "GPU is dead", a statement which was reiterated by now former Intel exec, Pat Gelsinger at IDF Spring 2008, happening in the city of Shanghai. Pat took charge of Larrabee and was certain that this architecture was the future of Intel. We agree 100% with Pat that the future of not just Intel, but AMD as well, as Larrabee is a merger between the CPU and the GPU. This applies for nVidia as well, but that's another topic.


Now former Intel VP Pat Gelsinger showcasing Larrabee wafer a year after infamous IDF China keynote

The only problem is, Intel sparked a war with nVidia without even having working silicon [ok, silicon capable of displaying a picture]. And that was a big mistake. The moment Jen-Hsun saw the comments made by Intel engineers and later statements by Intel execs at IDF Spring 2008 in Shanghai, Jen-Hsun "opened a can of whoop-ass" on Intel. Luckily for Intel, Jen-Hsun didn't have the GT300 silicon either, but GT200 was at the gates.
The strained relationship between the two got into a state of war when Intel started talking to OEMs and claiming that nVidia does not have the right to create chipsets for Nehalem [QPI - Quick Path Interface] and Lynnfield [DMI - Digital Multimedia Interface]. Upon request, we were shown a cross-license deal between Intel and nVidia. I am not going to disclose which side showed it to me, since technically - the source did something it wasn't supposed to do.

The wording in the original document, as far as my laic understanding, does not bar nVidia from making chipsets for Intel even after Front Side Bus is dead, because both QPI and DMI qualify as a "processor interconnect", regardless of what either party is saying.

Intel filed a suit against nVidia in Delaware court [naturally, since both companies are incorporated in the "Venture Capital of the World" state], claiming that nVidia doesn't hold the license for CPUs that have integrated memory controller. nVidia didn't stand back, but pulled a counter-suit, but this time around, nVidia wanted the cross-license deal annulled and to stop Intel from shipping products that use nVidia patents.

If you wonder why this cross-license agreement is of key importance for Larrabee, the reason is simple: without nVidia patents, there is no Larrabee. There are no integrated chipsets either, since they would infringe nVidia's patents as well. Yes, you've read that correctly. The Larrabee architecture uses some patents from both ATI and nVidia, just like every graphics chip in the industry. You cannot invent a chip without infringing on patents set by other companies, thus everything is handled in a civil matter - with agreements. We heard a figure of around several dozen patents, touching Larrabee from the way how frame buffer is created to the "deep dive" called memory controller. If you end up in court, that means you pulled a very wrong move, or the pursuing company is out to get you. If a judge would side with nVidia, Larrabee could not come to market and well can you say - Houston, we have a problem?

Intel had the luck of AMD snatching ATI - Intel and AMD have a cross-license agreement that allows for technology to transfer both ways - Intel had no problems getting a license for Yamhill i.e. AMD64, 64-bit extensions for their CPU architecture and equally should have no issues of using ATI patent portfolio [ATI and Intel already had an agreement]. My personal two cents would be going on Intel giving an x86 license to nVidia in exchange for cross-license patent, but only time will tell how the situation will develop. However, there is a reason why Bruce Sewell "retired" from arguably the best or second best legal post in the industry [IBM or Intel, we'll leave you to pick] and then show up at Apple two days after that "retiring" e-mail.

All that this unnecessary war created was additional pressure on engineers, who had to check and re-check their every move with Larrabee, causing further delays to the program. We completely understand these people - these chips are their babies. But the additional legal pressure caused some people to leave. This is nothing weird - with projects of this size, people come and go.

But Larrabee was coming, and it was coming without the "it works" component.