Silvermont

Silvermont
General information
Launched	From 2013
Common manufacturer(s)	Intel;
Architecture and classification
Min. feature size	22 nm
Architecture	Silvermont x86
Instructions	MMX, AES-NI, RDRAND, CLMUL
Extensions	x86-64, Intel 64; SSE, SSE2, SSE3, SSSE3, SSE4, SSE4.1, SSE4.2; VT-x;
Physical specifications
Cores	2–8;
Products, models, variants
Brand name(s)	Atom; Celeron; Pentium;
History
Predecessor	Bonnell; Saltwell
Successor	Airmont (die shrink),; Goldmont (new microarchitecture)

Silvermont is a microarchitecture for low-power Atom, Celeron and Pentium branded processors used in systems on a chip (SoCs) made by Intel. Silvermont forms the basis for a total of four SoC families:[1]

Merrifield and Moorefield – consumer SoCs intended for smartphones
Bay Trail – consumer SoCs aimed at tablets, hybrid devices, netbooks, nettops, and embedded/automotive systems
Avoton – SoCs for micro-servers and storage devices
Rangeley – SoCs targeting network and communication infrastructure.

According to the Tick–tock model Silvermont is the 22 nm die shrink (Tick) of Saltwell and Saltwell is the 32 nm die shrink of Bonnell so Silvermont seems to be part of the same microarchitecture named Bonnell. Silvermont was announced to news media on May 6, 2013 at Intel's headquarters at Santa Clara, California.[2][3] Intel had repeatedly said the first Bay Trail devices would be available during the Holiday 2013 timeframe, while leaked slides showed that the release window for Bay Trail-T as August 28 – September 13, 2013.[4] Both Avoton and Rangeley were announced as being available in the second half of 2013. The first Merrifield devices were announced in 1H14.[5]

Airmont is the 14 nm die shrink of Silvermont, launched in early 2015 and first seen in the Atom x7-Z8700 as used in the Microsoft Surface 3.[6] Airmont microarchitecture includes the following SoC families:[7]

Braswell – consumer SoCs aimed at PCs
Cherry Trail – consumer SoCs aimed at tablets.

Silvermont based cores have also been used, modified, in the Knight's Landing iteration of Intel's Xeon Phi HPC chips.

Design

Silvermont was the first Atom processor to feature an out-of-order architecture.[8]

Technology

A 22 nm manufacturing process based on 3D tri-gate transistors
SoC (System on Chip) architecture
Consumer chips up to quad-core, business-class chips up to eight cores
Supports SSE4.2 instruction set
Gen 7 Intel HD Graphics with DirectX 11, OpenGL 4.0, and OpenCL 1.1 support. OpenGL 4.0 is supported with 10.18.10.5161 WHQL [9][10] and later drivers. On Android, Silvermont graphics is OpenGL ES 3.1 certified.[11]
10 W TDP desktop processors
4.5 and 7.5 W TDP mobile processors
20 W TDP Server and Communications processors

Erratum

Intel revealed in its Q4 2016 quarterly report that there were quality issues in the C2000 product family, which had an effect on the financial performance of the company's Data Center Group that quarter.[12] An erratum named AVR54 published by Intel state there is a defect in the chip's LPC clock, and affected systems "may experience inability to boot or may cease operation".[13][14][15] A workaround is available requiring platform hardware changes. The SoC failures are thought to have led to failures in Cisco and Synology products,[16] though discussion of the C2000 as the root cause of failure has been reported to be under a non-disclosure agreement for many vendors.[17]

Intel released a new C0 stepping of the C2000 series in April 2017 which corrected the bug.[18]

In July 2017 Intel published that a similar quality issue affects also Atom E3800 series embedded processors. The erratum named VLI89 published by Intel state, similar to issue with Atom C2000, that there is a defect in the chip's LPC clock and affected systems "may experience inability to boot or may cease operation".[19] Issues extend also to USB bus and SD card circuitry and should happen "under certain conditions where activity is high for several years". In April 2018 Intel announced it is releasing a new D1 stepping to fix the issue.[20]

The LPC, USB and SD Card buses circuitry degradation issues also apply to other Bay Trail processors such as Intel Celeron J1900 and N2800/N2900 series;[21] also to Pentium N3500, J2850, J2900 series; and Celeron J1800 and J1750 series -- as those are based on the same affected silicon.

Cisco stated failures of Atom C2000 processors can occur as early as 18 months of use with higher failure rates occurring after 36 months.[22]

Mitigations were found to limit impact on systems. Firmware update for the LPC bus called LPC_CLKRUN# reduces the utilization of the LPC interface what in turn decreases (but not eliminates) LPC bus degradation - some systems are however not compatible with this new firmware. USB should have a maximum of 10% active time and there is a 50TB transmit traffic life expectancy over the lifetime of the port. It is recommended not to use SD card as a boot device and to remove the card from the system when not in use.

Bay Trail issues on Linux: It has been widely reported that Bay Trail cpus (and possibly their derivatives including Airmont/Braswell/Cherry Trail) experience random freezes / lock-ups on various Linux kernels. Reference linux bug report 109051 on Kernel.org Bugzilla, first reported Dec-2015. Workaround seems to be setting the linux kernel flag intel_idle.max_cstate=1, which while eliminating the system freezes/lock-ups, results in increased cpu power/battery usage by preventing the cpu from entering higher power-saving C-states. Systems running Windows-OSes apparently do not experience these lockup/freeze issues.

Bay Trail issues on FreeBSD: To solve the problem on FreeBSD, please try to set hw.acpi.cpu.cx_lowest=C1 and dev.cpu.<n>.lowest via /etc/sysctl.conf.

Airmont issues noted: 14nm Airmont architecture processors are also affected by the design flaws as noted in the Braswell Specification Update under CHP49 errata.[23] In addition to LPC and SD Card circuitry degradation issues those 14nm designs also have issues with Real Time Clock (RTC) circuitry degradation, their USB buses are however not affected. Unspecified firmware changes are required to mitigate RTC circuitry degradation. Intel does not plan to release a new stepping for Braswell.

Intel admitted on the issue stating the impact on consumers depends on use condition.[24]

List of Silvermont processors

Desktop processors (Bay Trail-D)

List of desktop processors as follows:

Target segment	Cores (threads)	Processor branding and model		GPU Model	TDP	Turbo	Graphics Clock rate		L2 cache	Release date	Price (USD)
Target segment	Cores (threads)	Processor branding and model		GPU Model	TDP	1-core	Normal	Turbo	L2 cache	Release date	Price (USD)
Value	4 (4)	Pentium	J2900	Intel HD Graphics (4 EU)	10 W / 2.41 GHz	2.67 GHz	688 MHz	896 MHz	2 MB	Q4 2013	$94
		Pentium	J2850		10 W / 2.41 GHz	N/A		792 MHz		Q3 2013	$94
		Celeron	J1900		10 W / 2.0 GHz	2.42 GHz		854 MHz		Q4 2013	$82
			J1850		10 W / 2.0 GHz	N/A		792 MHz		Q3 2013	$82
	2 (2)		J1800		10 W / 2.41 GHz	2.58 GHz		792 MHz	1 MB	Q4 2013	$72
	2 (2)		J1750		10 W / 2.41 GHz	N/A		750 MHz	1 MB	Q3 2013	$72

Server processors (Avoton)

It has been found that a bug in the blueprint of the C2000 CPUs family may cause failure of its embedded Ethernet ports.

List of server processors as follows:[25]

Target segment	Cores (threads)	Processor branding and model		GPU Model	TDP	CPU Turbo	Graphics Clock rate		L2 cache	Release date	Price (USD)
Target segment	Cores (threads)	Processor branding and model		GPU Model	TDP	1-core	Normal	Turbo	L2 cache	Release date	Price (USD)
Server	8 (8)	Atom	C2750	N/A	20 W / 2.4 GHz	2.6 GHz	N/A	N/A	4 MB	Q3 2013	$171
	8 (8)		C2730		12 W / 1.7 GHz	2.0 GHz			4 MB		$150
	4 (4)		C2550		14 W / 2.4 GHz	2.6 GHz			2 MB		$86
	4 (4)		C2530		9 W / 1.7 GHz	2.0 GHz			2 MB		$70
	2 (2)		C2350		6 W / 1.7 GHz	2.0 GHz			1 MB		$43

Communications processors (Rangeley)

List of upcoming communications processors as follows:[26]

Target segment	Cores (threads)	Processor branding and model		GPU Model	TDP	CPU Turbo	Graphics Clock rate		Intel QuickAssist	L2 cache	Release date	Price (USD)
Target segment	Cores (threads)	Processor branding and model		GPU Model	TDP	1-core	Normal	Turbo	Intel QuickAssist	L2 cache	Release date	Price (USD)
Communications	8 (8)	Atom	C2758	N/A	20 W / 2.4 GHz	N/A	N/A	N/A	Yes	4 MB	Q3 2013	$208
			C2738		20 W / 2.4 GHz				No			$208
			C2718		18 W / 2.0 GHz				Yes			$182
	4 (4)		C2558		15 W / 2.4 GHz				Yes	2 MB		$104
			C2538		15 W / 2.4 GHz				No			$104
			C2518		13 W / 1.7 GHz				Yes			$91
			C2508		9.5 W / 1.25 GHz						Q2 2014	$98
	2 (2)		C2358		7 W / 1.7 GHz	2.0 GHz				1 MB	Q3 2013	$60
			C2338		7 W / 1.7 GHz	2.0 GHz			No		Q3 2013
			C2308		6 W / 1.25 GHz	N/A			Yes		Q2 2014

Embedded/automotive processors (Bay Trail-I)

List of embedded processors as follows:[27]

Target segment	Cores (threads)	Processor branding and model		GPU Model	TDP	CPU Turbo	Graphics Clock rate		L2 cache	Release date	Price (USD)
Target segment	Cores (threads)	Processor branding and model		GPU Model	TDP	1-core	Normal	Turbo	L2 cache	Release date	Price (USD)
Embedded	4 (4)	Atom	E3845	Intel HD Graphics (4 EU)	10 W / 1.91 GHz	N/A	542 MHz	792 MHz	2 MB	Q4 2013	$52
	2 (2)		E3827		8 W / 1.75 GHz		542 MHz	792 MHz	1 MB		$41
			E3826		7 W / 1.46 GHz		533 MHz	677 MHz			$37
			E3825		6 W / 1.33 GHz		533 MHz	N/A			$34
	1 (1)		E3815		5 W / 1.46 GHz		400 MHz		512 KB		$31
	2 (2)		E3805	N/A	3 W / 1.33 GHz		N/A		1 MB	Q4 2014	$31

Mobile processors (Bay Trail-M)

List of mobile processors as follows:

Target segment	Cores (threads)	Processor branding & model		GPU model	TDP	CPU turbo	Graphics Clock rate		L2 cache	Release date	Price (USD)
Target segment	Cores (threads)	Processor branding & model		GPU model	TDP	CPU turbo	Normal	Turbo	L2 cache	Release date	Price (USD)
Value	4 (4)	Pentium	N3540	Intel HD Graphics (4 EU)	7.5 W / 2.16 GHz	2.66 GHz	313 MHz	896 MHz	2 MB	2014-07-20	$161
			N3530		7.5 W / 2.16 GHz	2.58 GHz		896 MHz		2014-02-23
			N3520		7.5 W / 2.166 GHz	2.42 GHz		854 MHz		2013-11-03
			N3510		7.5 W / 2.0 GHz	N/A		750 MHz		2013-09-11
		Celeron	N2940		7.5 W / 1.83 GHz	2.25 GHz		854 MHz		Q3 2014	$107
			N2930		7.5 W / 1.83 GHz	2.16 GHz		854 MHz		2014-02-23
			N2920		7.5 W / 1.86 GHz	2.0 GHz		844 MHz		2013-11-03
			N2910		7.5 W / 1.6 GHz	N/A		756 MHz		2013-09-11
	2 (2)		N2840		7.5 W / 2.16 GHz	2.58 GHz	311 MHz	792 MHz	1 MB	Q3 2014
			N2830		7.5 W / 2.16 GHz	2.41 GHz	313 MHz	750 MHz		2014-02-23
			N2820		7.5 W / 2.13 GHz	2.39 GHz		756 MHz		2013-11-03
			N2815		7.5 W / 1.86 GHz	2.13 GHz				2013-11-03
			N2810		7.5 W / 2.0 GHz	N/A				2013-09-11
			N2808		4.5 W / 1.58 GHz	2.25 GHz	311 MHz	792 MHz		Q3 2014
			N2807		4.3 W / 1.58 GHz	2.16 GHz	313 MHz	750 MHz		2014-02-23
			N2806		4.5 W / 1.6 GHz	2.0 GHz		756 MHz		2013-11-03
			N2805		4.3 W / 1.46 GHz	N/A		667 MHz		2013-09-11

Tablet processors (Bay Trail-T)

List of tablet and hybrid processors as follows:

Target segment	Cores (threads)	Processor branding & model		SDP[28]	CPU clock rate		L2 cache	GPU Model	GPU Clock rate		Memory					Max Display Resolution	Socket	Release date	Price (USD)
Target segment	Cores (threads)	Processor branding & model		SDP[28]	Base	Turbo	L2 cache	GPU Model	Base	Burst	Type	# Channels	Max Speed	Max Bandwidth	Max Supported	Max Display Resolution	Socket	Release date	Price (USD)
Value	4 (4)	Atom	Z3795	2 W	1.66 GHz	2.39 GHz	2 MB	Intel HD Graphics (4 EU)	311 MHz	778 MHz	LPDDR3	2x64b	1067MT/s	17.1 GB/s	4 GB		FCBGA1380	Q1 2014	$40.00
			Z3785	2.2 W	1.49 GHz	2.41 GHz			313 MHz	833 MHz	LPDDR3	2x64b	1333MT/s	21.3 GB/s	4 GB			Q2 2014
			Z3775	2 W	1.46 GHz	2.39 GHz			311 MHz	778 MHz	LPDDR3	2x64b	1067MT/s	17.1 GB/s	4 GB			Q1 2014	$35.00
			Z3775D	2.2 W	1.49 GHz	2.41 GHz			311 MHz	792 MHz	DDR3L-RS	1x64b	1333MT/s	10.6 GB/s	4 GB			Q1 2014	$35.00
			Z3770	2 W	1.46 GHz	2.39 GHz			311 MHz	667 MHz	LPDDR3	2x64b	1067MT/s	17.1 GB/s	4 GB	2560×1600		11 September 2013	$37.00
			Z3770D	2.2 W	1.5 GHz	2.41 GHz			313 MHz	688 MHz	DDR3L-RS	1x64b	1333MT/s	10.6 GB/s	2 GB	1920×1280			$37.00
			Z3740	2 W	1.33 GHz	1.86 GHz			311 MHz	667 MHz	LPDDR3	2x64b	1067MT/s	17.1 GB/s	4 GB	2560×1600			$32.00
			Z3740D	2.2 W	1.33 GHz	1.83 GHz			313 MHz	688 MHz	DDR3L-RS	1x64b	1333MT/s	10.6 GB/s	2 GB	1920×1280			$32.00
			Z3735F	2.2 W	1.33 GHz	1.83 GHz			311 MHz	646 MHz	DDR3L-RS	1x64b	1333MT/s	10.6 GB/s	2 GB	1920×1200	FCBGA592	Q1 2014	$17.00
			Z3735G	2.2 W	1.33 GHz	1.83 GHz			311 MHz	646 MHz	DDR3L-RS	1x32b	1333MT/s	5.3 GB/s	1 GB	1200×800	FCBGA592	Q1 2014	$17.00
	2 (2)		Z3680		1.33 GHz	2.0 GHz	1 MB		311 MHz	667 MHz	LPDDR3	1x64b	1067MT/s	8.5 GB/s	1 GB	1280×800		11 September 2013	N/A
	2 (2)		Z3680D		1.33 GHz	2.0 GHz	1 MB		311 MHz	688 MHz	DDR3L-RS	1x64b	1333MT/s	10.6 GB/s	2 GB	1920×1280		11 September 2013	N/A

Smartphone processors (Merrifield)

List of smartphone processors as follows:

Model number	sSpec number	Cores	Frequency	GPU frequency	L2 cache	I/O bus	Memory	Voltage	TDP	Socket	Release date	Part number(s)	Release price (USD)
Atom Z3460	SR1WR (B1) SR20G (B1) SR20U (B1)	2	1.6 GHz	400–457 MHz	1 MB		2 × LPDDR3-1066				March 2014	FG8065201850100
Atom Z3480	SR1WS (B1) SR20F (B1)	2	2.13 GHz	457–533 MHz	1 MB		2 × LPDDR3-1066				March 2014	FG8065201850200

Smartphone processors (Moorefield)

List of smartphone processors as follows:

Model number	sSpec number	Cores	Frequency	GPU frequency	L2 cache	Memory	Release date	Part number(s)
Atom Z3530	SR1YR (B0)	4	1.33 GHz	457 MHz	2 × 1 MB	2 × LPDDR3-1600	H2 2014	GA8066301896101
Atom Z3560	SR1WW (B0) SR1WX (B0)	4	1.83 GHz	457–533 MHz	2 × 1 MB	2 × LPDDR3-1600	H2 2014	GA8066301600200
Atom Z3570		4	2.00 GHz	457–640 MHz	2 × 1 MB	2 × LPDDR3-1600	Q4 2014
Atom Z3580	SR1WU (B0) SR1WV (B0)	4	2.33 GHz	457–533 MHz	2 × 1 MB	2 × LPDDR3-1600	H2 2014	GA8066301600100
Atom Z3590		4	2.50 GHz	457–640 MHz	2 × 1 MB	2 × LPDDR3-1600	H2 2015

List of Airmont processors

Desktop processors (Braswell)