SP3 uses a Haswell U Series 15W TDP i5 or i7 processor (ignoring the entry i3 Y series unit). Assuming SP4 continues using the U series chips which is what I would expect to continue the highest performance possible. Broadwell U Series improvements over Haswell U were in the range of 20% 3D Graphics 50% Video Conversion 4% Productivity (CPU) 1.5 hr battery life. Skylake U Series improvements over Broadwell U are in the range of 16-34% (25%) better 3D Graphics Performance xx% better video performance with new dedicated video processing units. 15% CPU performance (productivity) 25% better battery life (1.4x) Summing up: 45% 3D Graphics Performance improvement 50+xx% video performance improvement 20% CPU performance improvement 3 hr better battery life OR an opportunity to reduce weight with a smaller battery or some combination of longer battery and less weight. Other considerations: SSD advancements should allow for faster, lighter, lower power Disk Performance. Screen technology advancements should allow for lower power consumption, thinner, and lighter weight Advancements in cooling technology such as Teflon coating to reduce airflow drag etc. resulting in 98% of peak thermal load capacity. Miscellaneous: .2-.3 pound weight reduction 1.46 - 1.56 pounds for 12.1 inch unit. 9 - 10 hr battery life. Almost no throttling for most workloads.