Filename: PENTIUM.TXT
WWW URL: http://www.firmware.com/support/bios/pentium.htm
FTP URL: ftp://ftp.firmware.com/text/pentium.txt
Revision: 09/22/98 TLS Micro Firmware Technical Support
Summary: Selected information on Pentium CPUs including speed,
voltage, multipliers, sockets, part numbers, etc.
Intel Pentium CPUsSpeed Voltage Bus Speed Multiplier ZIF Socket Number
60 MHz 5 volt 60 MHz none Socket 4 8050260 66 MHz 5 volt 66 MHz none Socket 4 8050266
75 MHz 3.3 volt 50 MHz x1.5 Socket 5 / 7 8050275 90 MHz 3.3 volt 60 MHz x1.5 Socket 5 / 7 8050290 100 MHz 3.3 volt 50 MHz x2 Socket 5 / 7 80502100 100 MHz 3.3 volt 66 MHz x1.5 Socket 5 / 7 80502100 120 MHz 3.3 volt 60 MHz x2 Socket 5 / 7 80502120 133 MHz 3.3 volt 66 MHz x2 Socket 7 80502133 150 MHz 3.3 volt 60 MHz x2.5 Socket 7 80502150 166 MHz 3.3 volt 66 MHz x2.5 Socket 7 80502166 200 MHz 3.3 volt 66 MHz x3 Socket 7 80502200
Some motherboards may need to be jumpered differently for the voltage requirements on the 60 and 66MHz CPUs. 60MHz voltage rating is 4.75v to 5.25v (5v +/- 5%) 66MHz voltage rating is 4.90v to 5.40v
75-200MHx Pentiums are rated for different voltages. Some motherboards will have jumpers to set different voltages for Pentium CPUs. All Pentium CPUs are marked with an S-Spec number. This is a five-character value beginning with SK, SU, SX, SY or SZ. The S-Spec number will appear on top of the CPU and sometimes on the bottom. On some CPUs, the S-Spec number is followed by a slash and three letters. The first letter indicates the voltage. S = Standard voltage, V = VRE voltage. If there are no characters following the S-Spec number, the S-Spec number will need to be referenced to determine the voltage specification. There is a chart in the Pentium FAQ on Intel's web site that lists S-Spec numbers and gives corresponding characteristics. Here is the URL for the Pentium FAQ: http://www.intel.com/procs/support/faqs/ppfaqx2.htm There are 3 different voltage ratings for Pentium CPUs: Standard Voltage = 3.135v - 3.6v VR (reduced voltage) = 3.300v - 3.465v VRE (reduced voltage and shifted range)
B-step = 3.45v - 3.60v
C2-step and higher = 3.40v - 3.60v If a Pentium is rated for standard voltage, it shouldn't matter how a motherboard is jumpered. If a motherboard has CPU voltage jumpers, it may be necessary to determine the voltage rating on the CPU in order to determine how to set the voltage jumpers.The internal CPU multiplier on the regular Pentium CPUs is determined by setting the state of two pins on the CPU, usually handled by motherboard jumpers or DIP switches.
Intel Pentium MMX CPUs (see later section for Pentium Upgrade MMX CPUs)Speed Voltage Bus Speed Multiplier ZIF Socket Number
166 MHz 3.3 volt 66MHz x 2.5
200 MHz 3.3 volt 66MHz x 3
233 MHz 3.3 volt 66MHz x 3.5
Intel Pentium Overdrive CPUsThese are meant to replace regular Pentium CPUs
Speed Voltage Replaces Bus Speed Multiplier Socket Number120/133MHz 5 volt 60/66MHz 60/66MHz x2 Socket 4 PODP5V133
125MHz 3.3 volt 75 MHz 50MHz x2.5 Socket 5/7 PODP3V125
150MHz 3.3 volt 90 MHz 60MHz x2.5 Socket 5/7 PODP3V150
166MHz 3.3 volt 100 MHz 66MHz x2.5 Socket 5/7 PODP3V166
The internal CPU multiplier is fixed on Pentium Overdrive CPUs.
Intel Pentium Overdrive CPUs with MMXThese are meant to replace regular Pentium CPUs
Speed Voltage Replaces Bus Speed Multiplier Socket Number
125/150MHz 3.3v 75/90MHz 50/60MHz x2.5 5/7 PODPMT60X150
166MHz 3.3v 100MHz 66MHz x2.5 5/7 PODPMT66X166
180MHz 3.3v 90/120/150 60MHz x3 5/7? PODPMT60X180
200MHz 3.3v 100/133/166 66MHz x3 7 PODPMT66X200
The internal CPU multiplier is fixed on Pentium MMX Overdrive CPUs.
Intel Pentium Pro CPUs - Socket 8Speed
150MHz
166MHz
180MHz
200MHz
Intel Pentium II (code-named Klamath) - Slot 1233MHz
266MHz
300MHz
Intel Pentium II (code-named Deschutes) - Slot 1333MHz
350MHz
400MHz
450MHz
Intel Celeron - Slot 1 (code-named Mendocino)Celeron 266 - 266MHz - no built-in cache
Celeron 300 - 300MHz - no built-in cache
Celeron 300A - 300MHz - 128K L2 cache built-in (9/98)
Celeron 333 - 333MHz - 128K L2 cache built-in (9/98)
IA-64 (code-named Merced)(in development as of 10/98)
AMD ( http://www.amd.com )AMD-K5-PR75 75MHz AMD-K5-PR90 90MHz AMD-K5-PR100 100MHz AMD-K5-PR133 133MHz AMD-K5-PR166 166MHz
AMD-K6/166 AMD-K6/200 AMD-K6/233 AMD-K6/266
K6 CPUs are MMX-equipped and are designed for Socket 7. K6 CPUs were released in April of 1997.
Cyrix ( http://www.cyrix.com )6x86-PR133+ 110MHz Socket 7 6x86-PR150+ 120MHz Socket 7 6x86-PR166+ 133MHz Socket 7 6x86-PR200+ 150MHz Socket 7
6x86MX-PR166GP Dual-voltage 2.9/3.3 Socket 7 66/133 60/150 6x86MX-PR200GP Dual-voltage 2.9/3.3 Socket 7 75/150 66/166 6x86MX-PR233GP Dual-voltage 2.9/3.3 Socket 7 75/188 6x86MX-PR266GP Dual-voltage 2.9/3.3 Socket 7
MediaGX (surface-mounted on motherboards designed around it)
IDT ( http://www.winchip.com )IDT Winchip C6 180MHz Socket 7 IDT Winchip C6 200MHz Socket 7 IDT Winchip C6 225MHz Socket 7 IDT Winchip C6 240MHz Socket 7
IDT WinChip C6+ 233MHz (1998) Socket 7 IDT WinChip C6+ 300MHz (1998) Socket 7
WinChip C6 CPUs were released in Octoberr of 1997. WinChip C6/C6+ CPUs are designed for Socket 7 motherboards.
Upgrade Packages
Evergreen ( http://www.evertech.com )MxPro 180 - uses IDT WinChip C6 180
MxPro 233 - uses AMD K6 MMX 233
Kingston (http://www.kingston.com )TCMMX/200 (Turbochip 200) - uses AMD K6 MMX 200
Powerleap ( http://www.powerleap.com )PL/ProMMX - This is actually just an adapter (voltage regulator) but
can also be ordered with CPU. This is meant to allow CPUs
such as AMD K6, Cyrix 6x86MX, and Intel Pentium MMX to
work in Socket 5 or Socket 7 motherboards.PL/OD54C - An adapter to allow faster Pentium (non-MMX) CPUs to
work in Socket 5 boards lacking multiplier options.PL/54C - An adapter to allow Socket 4 boards (Pentium 60/66) to
accept faster (Socket 5) Pentium CPUs.
Trinity Works ( http://www.trinityworks.com )Powerstacker K6 - uses AMD K6