Parent: Processor Architectures

Update 3  2017 Jan

Silicon-28 or 28Si

Perhaps just more than ten years ago, there was a company (isonics?) trying to get isotopically pure 28Si for use as silicon wafers. Natural silicon is 92.2% Si-28, 4.7% Si-29 and 3.1% Si-30. Isotopically pure silicon is supposed to have 3× better thermal conductivity.

Heat Sink

About 10 years ago, an idea was floated related to heat transfer. All metals exposed to oxygen form a oxide layer on the surface. The oxide layer happens to contribute a large part of the thermal resistance. Processors are made out of silicon, which is a (semiconducting-)metal. Intel places a (metal) heat spreader on top of the silicon. A (metal) heatsink then sits on top of the spreader. There is thermal grease to help ensure physical contact between the spreader and the heat sink. At each level, the silicon chip, the spreader (both sides), and the heat sink, there is an oxide layer that contributes thermal resistance.

The idea was to place the components in a hard vacuum, no oxygen or anything else. A laser or some other means is used to remove the oxide layer, exposing the bare metal. When two exposed metals are placed in contact, they bond, as though they were one piece of metal. Not that we are interested in the metal bond, but we are interested in low thermal resistance.


In the discussion on Knights Landing, I suggested that the Atom core might not be bad for transaction processing. The cheapest Xeon Phi is the 7210 at $2438. About $4700 in a system. What is the difference between Atom C2750 and 2758? Both are Silvermont 8-cores, no HT. Use ECC SODIMM.

Atom has changed since its original inception, not using out-of-order execution for simplicity and power-efficiency. Silvermont added OOO. Not sure about Goldmont. Is Atom to be a slimmed down Core? with 3-wide superscalar and manufactured on the SoC version of the process?