Editing intel/80486/486sx-20

{{intel title|i486SX-20}}
{{mpu
| name                = Intel i486SX-20
| no image            = Yes
| image               = 
| image size          = 
| caption             = 
| designer            = Intel
| manufacturer        = Intel
| model number        = i486SX-20
| part number         = A80486SX-20
| part number 2       = KU80486SX-20
| part number 3       = 03G9565
| market              = 
| first announced     = 
| first launched      = September 16, 1991
| last order          = 
| last shipment       = 

| family              = 80486
| series              = 486SX
| locked              = 
| frequency           = 20 MHz
| bus type            = FSB
| bus speed           = 20 MHz
| bus rate            = 20 MT/s
| clock multiplier    = 1
| s-spec              = SX406
| s-spec 2            = SX467
| s-spec 3            = SX492
| s-spec 4            = SX678
| s-spec 5            = SXE63
| s-spec 6            = SX587
| s-spec 7            = SX632
| s-spec 8            = SX672
| s-spec 9            = SZ700
| s-spec 10           = SZ740
| s-spec es           = 
| s-spec qs           = 
| cpuid               = 420

| microarch           = 80486
| platform            = 
| chipset             = 
| core name           = 486SX
| core family         = 
| core model          = 
| core stepping       = 
| process             = 1 µm
| process 2           = 800 nm
| transistors         = 1,185,000
| transistors 2       = 900,000
| technology          = CMOS
| die size            = 
| word size           = 32 bit
| core count          = 1
| max cpus            = 1
| max memory          = 4 GiB

| electrical          = Yes
| power               = 2.25 W
| v core              = 5 V
| v core tolerance    = 5%
| temp max            = 85 °C
| temp min            = 0 °C

| packaging           = Yes
| package             = CPGA-168
| package type        = CPGA
| package size        = 
| package 2           = PQFP-196
| package type 2      = PQFP
| package 3           = SQFP-208
| package type 3      = SQFP
| package 4           = TQFP-176
| package type 4      = TQFP
| socket              = Socket 1 
| socket 2            = Socket 2
| socket 3            = Socket 3
}}
'''i486SX-20''' was a fourth-generation [[x86]] [[microprocessor]] introduced by [[Intel]] in 1991. This chip, which is based on the {{intel|microarchitectures/80486|80486 microarchitecture}}, operated at 20 MHz. In contrast to the i486DX chips, the i486SX line had no functional [[FPU]] on-die.

== Cache ==
{{main|intel/microarchitectures/80486#Memory_Hierarchy|l1=80486 § Cache}}
{{cache info
|l1 cache=8 KiB
|l1 break=1x8 KiB
|l1 desc=4-way set associative
|l1 extra=(unified, write-through policy)
}}

== Graphics ==
This chip had no integrated graphics processing unit.

== Features ==
* {{intel|System Management Mode}} (SMM)

== See also ==
* {{intel|80486|80486 family}}
base frequency	20 MHz (0.02 GHz, 20,000 kHz) +
bus rate	20 MT/s (0.02 GT/s, 20,000 kT/s) +
bus speed	20 MHz (0.02 GHz, 20,000 kHz) +
bus type	FSB +
clock multiplier	1 +
core count	1 +
core name	486SX +
core voltage	5 V (50 dV, 500 cV, 5,000 mV) +
core voltage tolerance	5% +
cpuid	420 +
designer	Intel +
family	80486 +
first launched	September 16, 1991 +
full page name	intel/80486/486sx-20 +
instance of	microprocessor +
l1$ description	4-way set associative +
l1$ size	8 KiB (8,192 B, 0.00781 MiB) +
ldate	September 16, 1991 +
manufacturer	Intel +
max cpu count	1 +
max memory	4,096 MiB (4,194,304 KiB, 4,294,967,296 B, 4 GiB, 0.00391 TiB) +
max operating temperature	85 °C +
microarchitecture	80486 +
min operating temperature	0 °C +
model number	i486SX-20 +
name	Intel i486SX-20 +
part number	A80486SX-20 +, KU80486SX-20 + and 03G9565 +
power dissipation	2.25 W (2,250 mW, 0.00302 hp, 0.00225 kW) +
process	1,000 nm (1 μm, 0.001 mm) + and 800 nm (0.8 μm, 8.0e-4 mm) +
s-spec	SX406 +, SX467 +, SX492 +, SX678 +, SXE63 +, SX587 +, SX632 +, SX672 +, SZ700 + and SZ740 +
series	486SX +
smp max ways	1 +
technology	CMOS +
transistor count	1,185,000 +
word size	32 bit (4 octets, 8 nibbles) +