Silvermont

Silvermont
	Intel Mobile Celeron N2830
General information
Launched	From 2013
Common manufacturer	Intel;
Architecture and classification
Technology node	22 nm
Instructions	x86-16, IA-32, x86-64
Extensions	MMX, SSE, SSE2, SSE3, SSSE3, SSE4, SSE4.1, SSE4.2; AES-NI, RDRAND, CLMUL; VT-x;
Physical specifications
Cores	2–8;
Products, models, variants
Brand names	Atom; Celeron; Pentium;
History
Predecessors	Bonnell; Saltwell
Successors	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.

Silvermont is the successor of the Bonnell, using a newer 22 nm process (previously introduced with Ivy Bridge) and a new microarchitecture, replacing Hyper Threading with out-of-order execution.^[2]

Silvermont was announced to news media on May 6, 2013, at Intel's headquarters at Santa Clara, California.^[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]

According to the Tick–tock model 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
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

Errata

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. The issue had been addressed in the commit "drm/i915: Disable preemption and sleeping while using the punit sideband".

Bay Trail issues on FreeBSD

A potential fix is to set hw.acpi.cpu.cx_lowest=C1 and dev.cpu.<n>.lowest via /etc/sysctl.conf.

Airmont issues

14 nm 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 14 nm 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 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 (GHz)	GPU freq. (MHz)		L2 cache (MB)	Release date	Price (USD)
Target segment	Cores (threads)	Processor branding and model		GPU model	TDP	1-core	Base	Turbo	L2 cache (MB)	Release date	Price (USD)
Value	4 (4)	Pentium	J2900	HD Graphics (4 EU)	10 W / 2.41 GHz	2.67	688	896	2	Q4 2013	$94
		Pentium	J2850		10 W / 2.41 GHz	—		792		Q3 2013	$94
		Celeron	J1900		10 W / 2.0 GHz	2.42		854		Q4 2013	$82
			J1850		10 W / 2.0 GHz	—		792		Q3 2013	$82
	2 (2)		J1800		10 W / 2.41 GHz	2.58		792	1	Q4 2013	$72
	2 (2)		J1750		10 W / 2.41 GHz	—		750	1	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.^{[citation needed]}

List of server processors as follows:^[25]

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

Communications processors (Rangeley)

List of communications processors as follows:^[26]

Target segment	Cores (threads)	Processor branding and model		GPU model	TDP	CPU Turbo (GHz)	GPU freq.		Intel QuickAssist	L2 cache (MB)	Release date	Price (USD)
Target segment	Cores (threads)	Processor branding and model		GPU model	TDP	1-core	Normal	Turbo	Intel QuickAssist	L2 cache (MB)	Release date	Price (USD)
Communications	8 (8)	Atom	C2758	—	20 W / 2.4 GHz	—	—	—	Yes	4	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		$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				1	Q3 2013	$60
			C2338		7 W / 1.7 GHz	2.0			No		Q3 2013
			C2308		6 W / 1.25 GHz	—			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	GPU freq. (MHz)		L2 cache	Release date	Price (USD)
Target segment	Cores (threads)	Processor branding and model		GPU model	TDP	1-core	Base	Turbo	L2 cache	Release date	Price (USD)
Embedded	4 (4)	Atom	E3845	HD Graphics (4 EU)	10 W / 1.91 GHz	—	542	792	2 MB	Q4 2013	$52
	2 (2)		E3827		8 W / 1.75 GHz		542	792	1 MB		$41
			E3826		7 W / 1.46 GHz		533	677			$37
			E3825		6 W / 1.33 GHz		533	—			$34
	1 (1)		E3815		5 W / 1.46 GHz		400		512 KB		$31
	2 (2)		E3805	—	3 W / 1.33 GHz		—		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 (GHz)	GPU freq. (MHz)		L2 cache (MB)	Release date	Price (USD)
Target segment	Cores (threads)	Processor branding & model		GPU model	TDP	CPU turbo (GHz)	Base	Turbo	L2 cache (MB)	Release date	Price (USD)
Value	4 (4)	Pentium	N3540	Intel HD Graphics (4 EU)	7.5 W / 2.16 GHz	2.66	313	896	2	2014-07-20	$161
			N3530		7.5 W / 2.16 GHz	2.58		896		2014-02-23
			N3520		7.5 W / 2.166 GHz	2.42		854		2013-11-03
			N3510		7.5 W / 2.0 GHz	—		750		2013-09-11
		Celeron	N2940		7.5 W / 1.83 GHz	2.25		854		Q3 2014	$107
			N2930		7.5 W / 1.83 GHz	2.16		854		2014-02-23
			N2920		7.5 W / 1.86 GHz	2.0		844		2013-11-03
			N2910		7.5 W / 1.6 GHz	—		756		2013-09-11
	2 (2)		N2840		7.5 W / 2.16 GHz	2.58	311	792	1	Q3 2014
			N2830		7.5 W / 2.16 GHz	2.41	313	750		2014-02-23
			N2820		7.5 W / 2.13 GHz	2.39		756		2013-11-03
			N2815		7.5 W / 1.86 GHz	2.13				2013-11-03
			N2810		7.5 W / 2.0 GHz	—				2013-09-11
			N2808		4.5 W / 1.58 GHz	2.25	311	792		Q3 2014
			N2807		4.3 W / 1.58 GHz	2.16	313	750		2014-02-23
			N2806		4.5 W / 1.6 GHz	2.0		756		2013-11-03
			N2805		4.3 W / 1.46 GHz	—		667		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](W)	CPU freq. (GHz)		L2 cache (MB)	GPU model	GPU freq. (MHz)		Memory					Max display resolution	Socket	Release date	Price (USD)
Target segment	Cores (threads)	Processor branding & model		SDP^[28](W)	Base	Turbo	L2 cache (MB)	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	1.66	2.39	2	HD Graphics (4 EU)	311	778	LPDDR3	2x64b	1067MT/s	17.1 GB/s	4 GB		FCBGA1380	Q1 2014	$40.00
			Z3785	2.2	1.49	2.41			313	833			1333MT/s	21.3 GB/s				Q2 2014
			Z3775	2	1.46	2.39			311	778			1067MT/s	17.1 GB/s				Q1 2014	$35.00
			Z3775D	2.2	1.49	2.41				792	DDR3L-RS	1x64b	1333MT/s	10.6 GB/s				Q1 2014	$35.00
			Z3770	2	1.46	2.39				667	LPDDR3	2x64b	1067MT/s	17.1 GB/s		2560×1600		11 September 2013	$37.00
			Z3770D	2.2	1.5	2.41			313	688	DDR3L-RS	1x64b	1333MT/s	10.6 GB/s	2 GB	1920×1280			$37.00
			Z3740	2	1.33	1.86			311	667	LPDDR3	2x64b	1067MT/s	17.1 GB/s	4 GB	2560×1600			$32.00
			Z3740D	2.2		1.83			313	688	DDR3L-RS	1x64b	1333MT/s	10.6 GB/s	2 GB	1920×1280			$32.00
			Z3735F						311	646		1x64b		10.6 GB/s	2 GB	1920×1200	FCBGA592	Q1 2014	$17.00
			Z3735G							646		1x32b		5.3 GB/s	1 GB	1200×800	FCBGA592	Q1 2014	$17.00
	2 (2)		Z3680			2.0	1			667	LPDDR3	1x64b	1067MT/s	8.5 GB/s	1 GB	1280×800		11 September 2013	—
	2 (2)		Z3680D			2.0	1			688	DDR3L-RS	1x64b	1333MT/s	10.6 GB/s	2 GB	1920×1280		11 September 2013	—

Smartphone processors (Merrifield)

List of smartphone processors as follows:

Model	sSpec number	Cores	Clock rate	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)