Table is intended to show performance enhancement of switch ASICs -- arranged chronologically by announcement date. Cisco announces their new silicon along with its first products while merchant silicon manufacturers announce new ASICs perhaps a year before their customers are ready to ship first products. Where buffer is shown with a multiplier, the ASIC design is segmented into slices. Total packet buffer is the product of the numbers in the buffer column but only the segment amount is available to any one output port.

ASIC Announced buffer Geometry Sw BW
Cisco Cat3550 Dec 2001 2 Mbyte 8.8 Gb/s
HP Procurve ASIC Mar 2003 0.5 Mbyte 48 Gb/s
Broadcom BCM56314 Mar 2007 0.75 Mbyte 48 Gb/s
Broadcom Trident+ Mar 2010 9 Mbyte 40 nM 0.64 Tb/s
Broadcom Trident II Aug 2012 12 Mbyte 40 nM 1.28 Tb/s
Cisco Algoboost Sep 2012 18 Mbyte 480 Gb/s
Cisco UADP 1.0 Jan 2013 6 Mbyte 36 nM 56 Gb/s
Cavium Xpliant Sep 2014 24 Mbyte 28 nM 3.2 Tbps
Broadcom Tomahawk Sep 2014 4 x 4 Mbyte 28 nM 3.2 Tbps
Broadcom Trident II+ Apr 2015 16 Mbyte 28 nM 1.28 Tb/s
Mellanox Spectrum June 2015 16 Mbyte 28 nM 6.4 Tbps
Ciso Nexus LSE Mar 2016 2 x 20 Mbyte 16 nM 3.6 Tbps
Barefoot Tofino June 2016 22 Mbyte 16 nM 6.4 Tbps
Broadcom Tomahawk-II Oct 2016 4 x 10.5 Mbyte 16 nM 6.4 Tbps
Innovium Teralynx 7 Mar 2017 70 Mbyte 16 nM 12.8 Tbps
Broadcom Trident III June 2017 32 Mbyte 16 nM 3.2 Tbps
Cisco UADP 2.0 June 2017 2 x 16 Mbyte 28 nM 240 Gb/s
Mellanox Spectrum2 July 2017 42 Mbyte 16 nM 6.4 Tb/s
Broadcom Tomahawk-3 Dec 2017 64 Mbyte 16 nM 12.8 Tbps
Cisco UADP 3.0 Mar 2018 36 Mbyte 16 nM 1.6 Tbps
Intel Tofino2 Dec 2018 64 Mbyte 7 nM 12.4 Tbps
Broadcom Trident 4 June 2019 132 Mbyte 7 nM 25.6 Tbps
Broadcom Tomahawk 4 Dec 2019 116 Mbyte 7 nM 25.6 Tbps
Cisco One Q100 Dec 2019 HBM 16 nM 10.8 Tbps
Nvidia/Mellanox Spectrum3 Mar 2020 64 Mbyte 16 nM 12.8 Tbps
Innovium Terelynx 8 May 2020 170 Mbyte 7 nM 25.6 Tbps
Cisco Nexus GX2B June 2020 2 x 50 Mbyte 7 nM 25.6 Tbps
Cisco Nexus GX2A June 2020 4 x 25 Mbyte 7 nM 25.6 Tbps

Another way to look at this is in https://en.wikipedia.org/wiki/Semiconductor_device_fabrication. From that reference, the history of device fabrication is:

Semiconductor
device
fabrication
10000 nm 1971
6000 nm 1974
3000 nm 1977
1500 nm 1981
1000 nm 1984
800 nm 1987
600 nm 1990
350 nm 1993
250 nm 1996
180 nm 1999
130 nm 2001
90 nm 2003
65 nm 2005
45 nm 2007
32 nm 2009
22 nm 2012
14 nm 2014
10 nm 2016
7 nm 2018
5 nm 2020

ASIC	Announced	buffer	Geometry	Sw BW
Cisco Cat3550	Dec 2001	2 Mbyte		8.8 Gb/s
HP Procurve ASIC	Mar 2003	0.5 Mbyte		48 Gb/s
Broadcom BCM56314	Mar 2007	0.75 Mbyte		48 Gb/s
Broadcom Trident+	Mar 2010	9 Mbyte	40 nM	0.64 Tb/s
Broadcom Trident II	Aug 2012	12 Mbyte	40 nM	1.28 Tb/s
Cisco Algoboost	Sep 2012	18 Mbyte		480 Gb/s
Cisco UADP 1.0	Jan 2013	6 Mbyte	36 nM	56 Gb/s
Cavium Xpliant	Sep 2014	24 Mbyte	28 nM	3.2 Tbps
Broadcom Tomahawk	Sep 2014	4 x 4 Mbyte	28 nM	3.2 Tbps
Broadcom Trident II+	Apr 2015	16 Mbyte	28 nM	1.28 Tb/s
Mellanox Spectrum	June 2015	16 Mbyte	28 nM	6.4 Tbps
Ciso Nexus LSE	Mar 2016	2 x 20 Mbyte	16 nM	3.6 Tbps
Barefoot Tofino	June 2016	22 Mbyte	16 nM	6.4 Tbps
Broadcom Tomahawk-II	Oct 2016	4 x 10.5 Mbyte	16 nM	6.4 Tbps
Innovium Teralynx 7	Mar 2017	70 Mbyte	16 nM	12.8 Tbps
Broadcom Trident III	June 2017	32 Mbyte	16 nM	3.2 Tbps
Cisco UADP 2.0	June 2017	2 x 16 Mbyte	28 nM	240 Gb/s
Mellanox Spectrum2	July 2017	42 Mbyte	16 nM	6.4 Tb/s
Broadcom Tomahawk-3	Dec 2017	64 Mbyte	16 nM	12.8 Tbps
Cisco UADP 3.0	Mar 2018	36 Mbyte	16 nM	1.6 Tbps
Intel Tofino2	Dec 2018	64 Mbyte	7 nM	12.4 Tbps
Broadcom Trident 4	June 2019	132 Mbyte	7 nM	25.6 Tbps
Broadcom Tomahawk 4	Dec 2019	116 Mbyte	7 nM	25.6 Tbps
Cisco One Q100	Dec 2019	HBM	16 nM	10.8 Tbps
Nvidia/Mellanox Spectrum3	Mar 2020	64 Mbyte	16 nM	12.8 Tbps
Innovium Terelynx 8	May 2020	170 Mbyte	7 nM	25.6 Tbps
Cisco Nexus GX2B	June 2020	2 x 50 Mbyte	7 nM	25.6 Tbps
Cisco Nexus GX2A	June 2020	4 x 25 Mbyte	7 nM	25.6 Tbps

Semiconductor
device
fabrication
10000 nm	1971
6000 nm	1974
3000 nm	1977
1500 nm	1981
1000 nm	1984
800 nm	1987
600 nm	1990
350 nm	1993
250 nm	1996
180 nm	1999
130 nm	2001
90 nm	2003
65 nm	2005
45 nm	2007
32 nm	2009
22 nm	2012
14 nm	2014
10 nm	2016
7 nm	2018
5 nm	2020