Friday, November 09, 2018

Reflections on the AMD Revolution

The AMD-Intel struggle is nothing short of biblical in the world of computing.

Ever since the Athlon days, AMD has always been the innovator and Intel has always been the follower.

In 2001, AMD moved from shared front bus to point-to-point interconnect, the HyperTransport. Intel followed in 2008, with its QuickPath interconnect. NUMA became the norm.

In 2003, AMD launched the first AMD64 processor, the Opteron server chip with 64-bit extensions to x86. Intel eventually abandoned its dear-to-heart Itanium plans to followed suit. Nowadays, Intel Xeon and Core chips are all based on AMD64.

Similarly, Intel followed AMD's footsteps on other technological advances, such as IMC (embedded memory controller) and multi-core.

It would seem that Intel simply waited for AMD the innovator, and then moved up to copy and eat AMD's lunch. Intel was able to thrive on such parasitic strategy due to its size and monopolistic control of the market. It used to take AMD three to four years to gain meaningful market share, while Intel leisurely and unabashedly copy-catted the true innovator. When benchmark manipulation was no longer viable, Intel simply paid OEMs not to use AMD.

History seems to repeat itself. When AMD unleashed the EPYC ZEN architecture with four 8-core chips forming a massive 32-core/64 thread server CPU laden with advanced security features and vast I/O bandwidth in 2017, Intel ridiculed AMD for gluing four desktop chips into a server chip. The IT press was not amused. Intel's arrogant ignorance was universally condemned.

Now, EPYC Rome's revolutionary Zen 2 architecture has been partially unveiled.  With eight 7nm 8-core Zen core chiplets embracing a central I/O chip, AMD once again thought out of the box. It moved away from NUMA (at least in 1P) and achieved something beyond the imagination of the Intel engineers. AMD never ceases to amaze us,  so little resource, yet so much innovation.

The unimaginative Intel engineers are now being commanded by former AMD architects, with Jim Keller and Raja Koduri being the more notable ones. To counter the onslaught of the mighty Rome, a rash plan was hatched to glue two massive 700 mm^2 old Xeon dies to compose the so called Cascade Lake CPU. Essentially, Intel is cramping a 2-P server into a 1P socket, without the forethought of the chiplet technology. Unfortunately for Intel, it does not enjoy the power and density advantage of a 7nm process. The truly glued together Cascade Lake will have a heat production of over 350 watts, sufficient to fry your breakfast egg in minutes. Intel is desperate. Firing its veteran CEO doesn't seem to help. The old Intel machine with its internal bureaucracy and internal politics would resist any infusion of external blood. The situation spells doom for the blue team.

But if history repeats itself, would Intel suppress AMD again to buy time like it did in the Opteron days?

The current situation is different because of three reasons.

First, the anti-trust lawsuit launched by Hector Ruiz has constrained Intel's unlawful tactics. Intel was convicted and fined by the U.S. and EU governments. Dell was chastised for taking the bribes. AMD gained the right to outsource its wafer fabrication. If Intel were to do something naughty, it would have to be more subtle, such as hiding a weighty water chiller under the table for its 5GHz 28-core demo.

Second, Intel has lost the process lead as we approach the physical limits of optical wavelength and atomic radius. TSMC is moving towards 5nm and 3nm. Intel is still struggling with 10nm.

Third, AMD has learned its lessons. In the Opteron days, Henri Richard bragged about his fancy new car afforded by the elevated AMD stock price and boasted that Intel would never catch up. AMD was cocky those days. But BullDozer was a disaster. Intel overtook AMD with raw instructions per clock. Now, Dr. Lisa Su is not letting up her feet on the engine paddle. AMD fellow Mike Clark revealed in an interview that he was working on Zen 5. People conjectured that AMD skipped Zen 4 because of a Chinese superstition. Untrue! AMD is near completion on Zen 3. Zen 4 is underway. And we knew months ago, Zen 5 had been started.

Hail Caeser! Hail AMD!