Abstract
Multichip module packaging and its impact on architecture
The presentation compares the system packaging and technologies of IBM´s latest system z high end servers.
Starting from the z900, the system design change towards a blade-like architecture will be explained.
The latest system generation z9 has achieved a doubling of the multiprocessor performance compared to the z990 system by maximizing its CPU
configuration in combination with increasing the speed of the interconnections.
The heart of a processor node consists of a multi chip module (MCM) which contains the double core processor chip,
the cache chips and the bus adaptors to the memory and the IO chips.
This MCM technology is the key enabler for the high bandwidths between processor chips and the cache chips.
The glass ceramic module has accomplished this challenge within the 102 layers resulting in a total wiring length of 545m.
The increase of bandwidth requirements for the packaging will be compared for the last generations.
Also the complex board and card technology of the second level packaging will be discussed.
The cooling of the system is being done with a modular refrigeration unit (MRU),
which cools the processor chips down to 45C. This low temperature ensures highest reliability and reduced leakage current of the chips.
An air cooled backup mode at a lower frequency ensures that the system does not go down in case of an MRU fail.
The MCM has been designed for a maximum power of 850W during nominal operation and 1200W in case of the air-cooled backup mode.
The presentation will focus on the electrical design methodologies for high end servers like power delivery concepts, signal integrity methodologies and power integrity designs for delivering such high currents.