Slot 1

133 MHz ( VIA P6 chipsets )

Celeron: 266-433 MHz Pentium III: 450-1133 MHz ( A Slotket allows the operation of: Celeron and Pentium III up to 1400 MHz, Cyrix III: 350-733 MHz, VIA C3: 733-1200 MHz)

The Slot 1 is a processor socket for Intel processors of the series Pentium Pro, Pentium II, Celeron, Pentium III and some.


With introduction of the Pentium II, the transition from the base to the slot is necessary because, in this, the processor core and the cache memory are separate chips on a common board.

For the slot 1, there are cards that contain a base 8 to use Pentium Pro processors on Slot 1 motherboards can. However, these adapters are relatively rare.

Similarly, there are adapters that provide a 370 base available to use the newer processors in this socket. This also " Slotket " said adapters are partially equipped with its own voltage regulators to supply the newer CPUs with a lower core voltage can, as it can provide the motherboard normally.

Intel supports with the Slot 1 Symmetric Multiprocessing (SMP). A maximum of two Pentium II or Pentium III CPUs can be operated in a dual board. For the Celeron is no SMP support official.

The inserted at slot 1 mechanical connectors SC242 was later also used by AMD Slot A. However, he was attached to 180 ° on the boards, to prevent any confusion.


The design SECC (Single Edge Contact Cartridge ) was applied at the beginning of slot-1 era with the Pentium II. Here, the CPU is embedded in a plastic or metal hybrid package. The back is made ​​of plastic and is labeled " Pentium II", the company logo of Intel, a hologram, and the model number. The front consists of a black anodized aluminum plate which serves as a bearing surface for the processor cooler. The SECC design is considered very robust, as protected inside the case, the CPU is located. Unlike socket CPUs neither pins can break, nor the housing can be damaged by improper mounted radiator.

Then the SEPP design ( Single Edge Processor Package) came on the market, which was designed for the cheap Celerons. The housing has completely saved here, for cost reasons Intel.

The Pentium III CPUs came again in a housing therefore, SECC2 called. From the former SECC housing only the plastic side is still there, the aluminum plate was saved. The CPU is free. The heatsink is here as the Celeron directly on the CPU die.


Historically, there are three platforms for P6 class processors: Socket 8, Slot 1 and Socket 370

The Slot 1 is a successor of the base 8 While in base 8 (Pentium Pro), the L2 cache is located directly on the CPU, it is CPU die housed in Slot 1 CPUs, together with the on a board, the yield increase in the production process. An exception to the last slot 1 CPUs is with Coppermine core, in which the L2 cache in the The is already integrated.

Originally the base was meant 370 as a platform for low-cost Celeron and the slot as a platform for the more expensive Pentium II and Pentium III processors. Early 2000, but was replaced with the advent of the Pentium III CPUs in the FC - PGA Package Slot 1 through the base 370, after both port types were offered in parallel since the beginning of 1999. Was due to the favorable production that now - thanks to improved manufacturing processes - through the integration of the L2 cache on the Prozessordie was possible. Since the Pentium III development continued on the base 370, the Pentium remained III Coppermine core and 1000 MHz clock the fastest available CPU for the slot 1, while the Coppermine successor Tualatin up to 1.4 GHz only was offered for the socket 370.

The Slot 1 also solved - what Intel refers - the base 7 as a platform for the home user market from. Intel left with expiry of the Pentium MMX CPUs, the field of Socket 7 processors complete the manufacturers AMD, Cyrix and IDT.

Common chipsets for the slot 1 and officially supported CPUs

Intel 440FX

  • Introduction Date: May 6, 1996
  • FSB: 66MHz
  • Supported Memory Type: EDO DRAM
  • Supported CPUs: Pentium Pro
  • Pentium II with 66 MHz FSB
  • Early Celerons ( Covington, Mendocino )
  • Use in both motherboards with Socket 8 (Pentium Pro) as well as with Slot 1 (Pentium II, early Celerons )
  • Supports neither AGP nor SDRAM

Intel 440LX

  • Introduction Date: August 27, 1997
  • FSB: 66MHz
  • Supported Memory Type: SDRAM
  • Supported CPUs: Pentium II with 66 MHz FSB
  • Early Celerons ( Covington, Mendocino )
  • With this chipset AGP was introduced

Intel 440BX

Intel 440BX:

  • Introduction Date: April, 1998
  • FSB: 66 and 100 MHz
  • Supported Memory Type: SDRAM ( PC66 and PC100 )
  • Supported CPUs: Pentium II with 66 and 100 MHz FSB
  • Pentium III with 100 MHz FSB
  • Early Celerons ( Covington, Mendocino, Coppermine )

Via Apollo Pro 133A

  • Year: 2000
  • FSB: 66, 100, 133 MHz
  • AGP 4x mode
  • Support for all Slot 1 CPUs

( With suitable Slotket also the faster, socketed Celerons and Pentium III more CPUs are used in many chipsets. )

Support for the Pentium III EB on Slot-1 Motherboards

A special series of Pentium III Slot 1 is denoted by the addition of EB. The "E " stands for the Coppermine core and the "B" for a clocked with 133 MHz Front Side Bus. Curiously, there is no Intel chipset that officially supports 133MHz FSB on the slot 1. To operate the EB- slot-1 - types of the Pentium III, there are two possibilities: either one uses a board with the VIA Apollo Pro 133A chipset, which is, however, partially equipped with the faulty Southbridge 686B, or can be used the i440BX chipset beyond its specification, in which stable operation is quite possible in some boards.