CPUs come in a cartridge which contains the CPU chip, cache chips and a cache controller. Later CPUs like Celeron 'Mendocino' have on-die cache and thus the cartridge became unnecessary and so Slot 1 was replaced with Socket 370. Intel 440FX was the first Slot 1 chipset. Again, as in the Slot-1 Celeron, BR#1 is reserved (according to the Celeron's data sheet), so it will not work in a dual-processor system right out of the box. In addtion, A-MAX's Socket370 to Slot1 conversion card has B75 pin/contact documented as 'N/C', making the modifications even more difficult.
| Type | Slot |
|---|---|
| Chip form factors |
|
| Contacts | 242[1] |
| FSB protocol | AGTL+ |
| FSB frequency | 66, 100, and (on third-party chipsets) 133 MHz |
| Voltage range | 1.3 to 3.50 V |
| Processors | Pentium II: 233–450 MHz Celeron: 266–433 MHz |
| Predecessor | Socket 7 |
| Successor | Socket 370 |
| This article is part of the CPU socket series | |
Slot 1 refers to the physical and electrical specification for the connector used by some of Intel's microprocessors, including the Pentium Pro, Celeron, Pentium II and the Pentium III. Both single and dual processor configurations were implemented.
Intel switched back to the traditional socket interface with Socket 370 in 1999.
General[edit]
The remedy for these limitations is to abandon the Slot 1 CPU all together and use a FC-PGA (flip-chip) Coppermine CPU with a Slot 1 to FC-PGA adapter card (slocket). The Coppermine CPU can be either a Pentium III or a Celeron II. Here are the steps to upgrade the Asus P2B motherboard: Flush the P2B motherboard to the latest Bios 1012. Slot 1 refers to the physical and electrical specification for the connector used by some of Intel 's microprocessors, including the Pentium Pro, Celeron, Pentium II and the Pentium III. Both single and dual processor configurations were implemented. Intel switched back to the traditional socket interface with Socket 370 in 1999.
With the introduction of the Pentium II CPU, the need for greater access for testing had made the transition from socket to slot necessary. Previously with the Pentium Pro, Intel had combined processor and cache dies in the same Socket 8 package. These were connected by a full-speed bus, resulting in significant performance benefits. Unfortunately, this method required that the two components be bonded together early in the production process, before testing was possible. As a result, a single, tiny flaw in either die made it necessary to discard the entire assembly, causing low production yield and high cost.[citation needed]
Intel subsequently designed a circuit board where the CPU and cache remained closely integrated, but were mounted on a printed circuit board, called a Single-Edged Contact Cartridge (SECC). The CPU and cache could be tested separately, before final assembly into a package, reducing cost and making the CPU more attractive to markets other than that of high-end servers. These cards could also be easily plugged into a Slot 1, thereby eliminating the chance for pins of a typical CPU to be bent or broken when installing in a socket.
The form factor used for Slot 1 was a 5-inch-long, 242-contact edge connector named SC242. To prevent the cartridge from being inserted the wrong way, the slot was keyed to allow installation in only one direction. The SC242 was later used for AMD's Slot A as well, and while the two slots were identical mechanically, they were electrically incompatible. To discourage Slot A users from trying to install a Slot 1 CPU, the connector was rotated 180 degrees on Slot A motherboards.
With the new Slot 1, Intel added support for symmetric multiprocessing (SMP). A maximum of two Pentium II or Pentium III CPUs can be used in a dual slot motherboard. The Celeron does not have official SMP support.
There are also converter cards, known as Slotkets, which hold a Socket 8 so that a Pentium Pro CPU can be used with Slot 1 motherboards.[2] These specific converters, however, are rare. Another kind of slotket allows using a Socket 370 CPU in a Slot 1. Many of these latter devices are equipped with own voltage regulator modules, in order to supply the new CPU with a lower core voltage, which the motherboard would not otherwise allow.
Form factors[edit]
The Single Edge Contact Cartridge, or 'SECC', was used at the beginning of the Slot 1-era for Pentium II CPUs. Inside the cartridge, the CPU itself is enclosed in a hybrid plastic and metal case. The back of the housing is plastic and has several markings on it: the name, 'Pentium II'; the Intel logo; a hologram; and the model number. The front consists of a black anodized aluminum plate, which is used to hold the CPU cooler. The SECC form is very solid, because the CPU itself is resting safely inside the case. As compared to socket-based CPUs, there are no pins that can be bent, and the CPU is less likely to be damaged by improper installation of a cooler.
Following SECC, the SEPP-form (Single Edge Processor Package) appeared on the market. It was designed for lower-priced Celeron CPUs. This form lacks a case entirely, consisting solely of the printed-circuit board holding the components.
A form factor called SECC2 was used for late Pentium II and Pentium III CPUs for Slot 1, which was created to accommodate the switch to flip chip packaging.[3] Only the front plate was carried over, the coolers were now mounted straight to the PCB and exposed CPU die and are, as such, incompatible with SECC cartridges.
History[edit]
Historically, there are three platforms for the Intel P6-CPUs: Socket 8, Slot 1 and Socket 370.
Slot 1 is a successor to Socket 8. While the Socket 8 CPUs (Pentium Pro) directly had the L2-cache embedded into the CPU, it is located (outside of the core) on a circuit board shared with the core itself. The exception is later Slot 1 CPUs with the Coppermine core which have the L2-Cache embedded into the die.
In the beginning of 2000, while the Pentium-III-CPUs with FC-PGA-housing appeared, Slot 1 was slowly succeeded by Socket 370, after Intel had already offered Socket 370 and Slot 1 at the same time since the beginning of 1999. Socket 370 was initially made for the low-cost Celeron processors, while Slot 1 was thought of as a platform for the expensive Pentium II and early Pentium III models. Cache and core were both embedded into the die.
Slot 1 also obsoleted the old Socket 7, at least regarding Intel, as the standard platform for the home-user. After superseding the Intel P5Pentium MMX CPU, Intel completely left the Socket 7 market.
Chipsets and officially supported CPUs[4][5][edit]
Intel 440FX [6][edit]
- Introduced in: May 6, 1996
- FSB: 66 MHz
- PIO/WDMA
- Supported RAM type: EDO-DRAM
- Supported CPUs:
- Pentium II with 66 MHz FSB
- Celeron (Covington, Mendocino)
- Used in both Socket 8 (Pentium Pro) and Slot 1 (Pentium II, early Celerons)
- Does not support AGP or SDRAM
- Allowed up to two CPUs for SMP
Intel 440LX [7][edit]
- Introduced in: August 27, 1997
- FSB: 66 MHz
- Supported RAM type: EDO-DRAM, SDRAM
- Supported CPUs: Pentium II, Celeron
- AGP 2× Mode
- UDMA/33
- Pentium II with 66 MHz FSB
- Celeron (Covington, Mendocino)
- Introduced support for AGP and SDRAM
- Allowed up to two CPUs for SMP
Intel 440EX [8][edit]
- Introduced in: April, 1998
- FSB: 66 MHz
- Supported RAM type: EDO-DRAM, SDRAM
- Supported CPUs: Pentium II, Celeron
- AGP 2× Mode
- UDMA/33
- Pentium II with 66 MHz FSB
- Celeron (Covington, Mendocino)
- Same specifications as 440LX, but memory support limited to 256MB and no SMP support.
Intel 440BX [9][edit]
- Introduced in: April 1998
- FSB: 66 and 100 MHz (some motherboards supported overclocking to 133 MHz, allowing usage of Socket 370 CPUs using a Slocket)
- AGP 2× Mode (max memory mapping 32 or 64 MB)
- UDMA/33
- Supported RAM types: SDRAM (PC66 and PC100, PC133 with overclocking) up to 4 DIMMs of 256 MB
- Supported CPUs:
- Pentium II with 66 and 100 MHz FSB
- Pentium III with 100 MHz FSB (133 with overclocking)
- Celeron (Covington, Mendocino, Coppermine)
- Allowed up to two CPUs for SMP
Intel 440ZX[edit]
- Introduced in: November 1998
- FSB: 66 and 100 MHz (some motherboards supported overclocking to 133 MHz, allowing usage of Socket 370 CPUs using a Slocket)
- AGP 2× Mode
- UDMA/33
- Supported RAM types: SDRAM (PC66 and PC100, PC133 with overclocking)
- Supported CPUs:
- Pentium II with 66 and 100 MHz FSB
- Pentium III with 100 MHz FSB (133 with overclocking)
- Celeron (Covington, Mendocino, Coppermine)
Intel 820/820E (Camino)[edit]
- Introduced in: November 1999
- FSB: 66, 100, and 133 MHz
- AGP 4× Mode
- UDMA/66 (i820), UDMA/100 (i820E)
- Supported RAM types: RDRAM, SDRAM (PC133)
- Supported CPUs: All Slot 1 CPUs
- Allowed up to two CPUs for SMP
Via Apollo Pro / Pro+[edit]
- Introduced in: May 1998 (Pro Plus: Dec 1998)
- FSB: 66, 100 MHz (some motherboards supported overclocking to 133 MHz, allowing usage of Socket 370 CPUs using a Slocket)
- AGP 2× Mode
- UDMA/33 (VT82C586B/VT82C596A), UDMA/66 (VT82C596B)
- Supported CPUs:
- Pentium Pro with 66 MHz FSB
- Pentium II with 66 and 100 MHz FSB
- Pentium III with 100 MHz FSB (133 with overclocking)
- Celeron (Covington, Mendocino, Coppermine)
Via Apollo Pro 133[edit]
- Introduced in: July 1999
- FSB: 66, 100, and 133 MHz
- AGP 2× Mode
- UDMA/33 (VT82C596A), UDMA/66 (VT82C596B/VT82C686A), UDMA/100 (VT82C686B)
- Supported CPUs: All Slot 1 CPUs
Via Apollo Pro 133A[edit]
- Introduced in: Oct 1999
- FSB: 66, 100, and 133 MHz
- AGP 4× Mode
- UDMA/66 (VT82C596B/VT82C686A), UDMA/100 (VT82C686B)
- Supported CPUs: All Slot 1 CPUs
- Allowed up to two CPUs for SMP
See also[edit]
References[edit]
- ^'CPU Sockets Chart'. erols.com. Retrieved 2009-03-31.
- ^'PPro on a BX?-Usenet Gateway'.
- ^http://www.tomshardware.com/reviews/overclocking-special,94-2.html[dead link]
- ^List of Intel chipsets
- ^List of VIA chipsets
- ^Intel Corporation: 440FX PCIset Datasheet
- ^Intel Corporation: 440LX AGPset Design Guide[permanent dead link]
- ^Intel Corporation: 440EX AGPset Design Guide
- ^Intel Corporation: 440BX AGPset Design GuideArchived 2012-10-04 at the Wayback Machine
External links[edit]
| Wikimedia Commons has media related to Slot 1. |
- Intel's specifications for the SC242 connectors[permanent dead link]
- 1Socket 8
- 2Slot 1
Socket 8
Socket 8 was introduced in November 1995 and is the initial platform used for the P6 architecture, the Pentium Pro CPU. It was primarily used for workstations and servers, and mostly ignored by home users. Motherboards and the CPU itself were pricey, and Pentium Pro is not necessarily a significant improvement for typical home user applications. In the worst case, running 8/16-bit code, the PPro can be slower than a Pentium at the same clock speed. In the best case with 32-bit code or heavy FPU operation, it far outperforms Pentium.
For gamers the PPro was an exciting development. Its various improvements were highly beneficial for emerging 3D games. It can occasionally outperform the bottom Pentium II models.
The initial chipsets from Intel, 450KX/GX, are not ideal for gaming because of PCI deficiencies. It is best to use a later 440FX-based board. It is also a good idea to try the FastVid utility when playing SVGA DOS games because PCI throughput can be dramatically improved. Windows 9x video drivers usually take care of this though.
Chipsets
- Intel 450GX 'Orion'
- Intel 450KX 'Mars'
- Intel 440FX 'Natoma' (82441FX/82442FX/82371SB)
- Intel 440LX (82443LX/81371AB) AGP
- OPTi Discovery (82C650/651 or 650/651/652 with AGP)
- VIA 680 'Apollo P6'
Slot 1
Slot 1 was introduced in May 1997 and served as Intel's successor to Socket 7 and brought the P6 architecture to the home market. CPUs come in a cartridge which contains the CPU chip, cache chips and a cache controller. Later CPUs like Celeron 'Mendocino' have on-die cache and thus the cartridge became unnecessary and so Slot 1 was replaced with Socket 370.
440FX
Intel 440FX was the first Slot 1 chipset. It was originally designed for Pentium Pro and there are boards with both Socket 8 and Slot 1. 440FX lacks AGP, SDRAM support, and its IDE interface is limited to 16MB/s.
440LX
440LX introduced AGP, SDRAM support, and UDMA33. It still has a 66MHz FSB limit. The fastest CPU's that will work are the Pentium II 333MHz (or a Pentium II 400MHz downclocked to 366MHz), the Slot 1 Celeron 433MHz (though faster Celerons can be installed with the use of a slotket) or a downclocked Pentium III with the Katmai core (which will be recognised as a Pentium II usually by the BIOS). Other solutions are to use a special type of slotket that lets one use a Tualatin-core Celeron which will be underclocked also, but will provide a speed up to around 1000MHz. Some of the 440LX motherboards had issues with powering more modern AGP graphics cards.
440BX
The 440BX is an evolution of 440LX and was very popular. BX boards officially support 100MHz FSB, though many motherboard manufacturers feature other FSB speeds for overclocking. BX also supports up to 1GB of SDRAM.
440BX chipset notes:
- It doesn't support memory modules greater then 256MB.
- It's AGP slot requires 3.3v support from the AGP card.
- Overclocking the FSB to 133MHz will overclock the AGP bus to an out of spec 89MHz. PCI can remain at 33MHz with proper BIOS configuration.
- Not all BX motherboards will work with Coppermine CPUs and none support Tualatin without an adapter.
440ZX
This chipset is a low-cost version of the much more famous 440BX. It replaces 440EX, the 440LX's low-end counterpart, adding 100MHz FSB. Few drawbacks do exist when comparing 440ZX to 440BX, although they can be considered minor for most retro builds today:
- Lacks two memory banks, only 512MB total RAM supported.
- No SMP support, so there are no dual CPU boards based on 440ZX.
- No ECC/Parity RAM supported
The marketing effort behind this was to push some of the competition aside, providing entry-level logic with all the basic 440BX features, including 100MHz FSB. While some ZX-based boards were poorly built to further reduce the costs, others were as solid and reliable as a top-branded 440BX one. The ASUS P2-99 is a good example of such board.
810
The 810 (codename: Whitney) is a low end Intel chipset. The original chipset supports only a FSB of 100 MHz, the enhanced 810E and 810E2 support 133 MHz. None supports AGP graphics. The ASUS P3W-E is an example of a Slot 1 motherboard with 810.
815
There were some Slot 1 motherboards based on the Intel 815 chipset. Examples include SOYO SY-7ISM (with both Slot 1 and Socket 370) and Abit SH6.
820
The i820 chipset is designed to support only RDRAM and only 1.5v AGP, although some motherboards feature special RDRAM to SDRAM bridge chip. Using the bridge significantly affects memory bandwith and overall performance.
840
This chipset is a workstation/server logic, SMP capable, usually found in dual CPU motherboards. The i840 supports dual-channel PC600/PC800 RDRAM, ECC or non-ECC modules. There is no option to run this chipset in a single-channel mode, so, unlike i820, modules have to be installed in matching pairs. The memory controller first introduced in i840 is quite similar to those found in later NetBurst-supporting i850 and i860. In fact, its optional Intel 82803AA MRH-R (Memory Repeater Hub) is compatible with i860 as well.
The i840 was targeted to replace the aging 440BX/GX (as the x40 name may suggest) and is therefore a collection of pioneering and unique features implemented to outperform and outshine older chipsets:
- First x86 chipset to support RDRAM.
- First Intel chipset to support AGP 4x, as well as AGP Pro.
- First Intel chipset to combine AGP and official 133MHz FSB.
- 2GB of RAM (4GB with MRH-R)
The i840 board is a sensible, though expensive choice for a retro build. It will run reliably under Windows 98/98SE/ME (with single CPU and obvious RAM limitations), as well as NT4.0 and later NT-derived OSes. Retro games may benefit from faster AGP and wider RAM bus, but will lack raw CPU power compared to i815 B-Step systems due to no Tualatin support.
Other
There are some other chipsets that feature Slot 1. VIA chipsets tend to be less stable but have some advantages compared to BX because some feature AGP 2/4x, 133 MHz FSB and support for larger SDRAM memory modules.
Most Slot 1 boards are made in the ATX form factor but some AT versions have been made.
Today:: Slot 1 comes with a single significant advantage that seems to outweight all other benefits, as well as all downsides, and this advantage is called 'BX'. There were more chipsets available for Slot 1, but most others usually have some kind of disadvantage compared to BX.What makes BX so great and what makes BX so popular amongst retro computer enthusiasts is the great flexibility and stability BX motherboards often offer.BX has the advantage of supporting up to 1GB of SDRAM using 4 DIMM sockets (Intels own i815 was limited to 512MB) and was a very stable platform with very few critical hardware quirks. It also has good compatibility and BX motherboards often sport as many as 3 ISA slots in addition to the then usual PCI slots and the AGP slot.CPU support is pretty good out of the box, with basically all BX Slot 1 boards supporting anything from Klamath (early Pentium 2) and Deschutes (late Pentium 2) up to Katmai (early Pentium 3 which was only released in Slot 1 form). Quite a lot of the BX boards had native support for Coppermine Slot 1 CPUs as well, but compatibility differs between different Slot 1 BX motherboard models, often even between different revisions of the same motherboard. In some cases one revision of a certain motherboard may actually (unofficially) support Coppermine while another board with the exact same revision will not (ASUS P2B rev 1.10 being a great example of that, with rev 1.12 being the first P2B to officially support Coppermine).Officially Slot 1 was designed to only accept Slot 1 CPUs with the higher end Coppermines being the top of the line. But these Slot 1 Coppermines are not as easy to find compared to it's Socket 370 counterparts. It is still possible to install a Socket 370 CPU into a Slot 1 motherboard by use of a slotkey and with a slotket even a 1.4GHz Tualeron CPU suddenly is within reach.
Some people also find the peculiar Slot 1 design to be interesting and in some ways it has it's advantages. One such advantage is that, as the CPU is basically one giant cartridge with the CPU cooler part of the cartridge, swapping CPUs is an easy chore which is as easy as swapping around any dedicated PCI or AGP card, one doesn't need to remove the CPU HSF, clean the old CPU of it's TIM (Thermal Interface Material), replace it with new CPU and reinstall the CPU HSF again.
The disadvantages of BX are mostly related to it's native 2x AGP slot (AGP 8x cards won't work in BX) in addition to some of it's AGP slots having problems with AGP cards which need a lot of power. Another disadvantage is BX's inability to use SDRAMs with more than 256MB per module (BX supports SDRAMs with 16MB/chip and a higher density will, at best, result in only part of the total memory size of that module being recognized).
Socket 370
- See also: List of Socket 370 motherboards
Introduced in January 1999, Socket 370 was originally made as a budget CPU socket. Later it became Intel's main CPU Socket until the release of the Pentium 4, after which it moved to the budget end of the market again before being phased out altogether.
Common chipsets for Socket 370 are Intels i815 chipset and it's VIA counterparts, though other chipsets like 440BX and even 440LX were also used for Socket 370 boards. Especially the 815 and VIA 694 chipsets are very popular these days for use as a base for a retro computer. Socket 370 BX remains a good and popular option also, though the vast majority of BX boards came with Slot 1 instead of Socket 370.
Slot 1 Celeron Games
A wide variety of CPU's exist for this socket, ranging from the 333MHz Celeron (with Mendocino core) all the way to the Pentium III-S 1400MHz (also known as Tualatin-S). VIA also made a variety of CPU's for this socket, though compatibility is somewhat sketchy.
As this CPU socket went through a few revisions, not all Socket 370 CPU's will work in any given Socket 370 motherboard. Generally speaking there are 3 different types of motherboards using this socket: the early Celeron Mendocino-only motherboards (usually limited to a 66MHz FSB and often these boards will be equipped with Intels 440LX chipset), the Coppermine capable motherboards (having a maximum FSB of either 100MHz or 133MHz) and the Tualatin capable motherboards. Sometimes Tualatin capable motherboards have their CPU socket colored blue instead of the usual white.
To prevent usage of newer CPU's in older motherboards, Intel switched a couple pins around to prevent operation of Coppermine CPU's in the earliest Celeron-only boards and Intel repeated that trick when it started manufacturing Tualatin CPU's. This prevented the use of later chips in older motherboards, even if the right (lower) voltage could be supplied by the motherboard.
Usually Socket 370 boards have AGP slots, unless an IGP is present. The older ones have an AGP 2x (3.3V) and the newer ones have a universal 1.5V AGP 4x slot. Motherboards using ALi's M1631 (Aladdin TNT2) or Intel's i810/810E chipsets do not support an AGP slot. All Socket 370 motherboards have PCI slots and the older types of Socket 370 motherboards have ISA slots. ISA slots are more common on motherboards using non-Intel chipsets. Almost all Socket 370 motherboards are ATX (though a few AT Socket 370 motherboards are known to exist). Only very few Tualatin motherboards featured one or 2 ISA slots. Usually motherboards with the Intel i815 chipset have no ISA slots, except when the motherboard is equipped with a bridge chip. The bridge chip may cause some problems when using ISA sound cards.
The Intel i810/815 chipsets also only support up to 512 MB of SDRAM. Its main competitors didn't have that limitation. Even though Socket 370 will usually come with SDRAM slots, a few Socket 370 motherboards were made that will work with either RDRAM or DDR instead.
All Intel Socket 370 CPUs have their multiplier locked, which decreases it's effectiveness when it comes to underclocking (Socket 7 doesn't have this problem and for DOS Socket 7 is overall a more popular choice). However, many Intel Socket 370 ES (Engineering Sample) CPUs and most (if not all) VIA C3 CPUs can have their CPU multiplier changed, usually by either software or from the BIOS. ES CPUs are quite rare though and not all may come with their CPU multiplier unlocked.
Because Socket 370 shares it's dimensions with Socket A, CPU Coolers for Athlon XP are physically compatible with Socket 370 and as Athlon XP CPU coolers are typically newer, beefier and easier to find, using a CPU cooler designed for Athlon XP is very popular when building a Socket 370 retro computer.However, one should note that installing of many Socket A or Socket 370 CPU coolers for use of Socket 370 CPUs which come with an Integrated Heatspreader (or IHS) may prove difficult.
Today:: Socket 370 is a very popular basis for a retro computer these days, for several reasons.One reason is that these high-end Pentium 3 motherboards are widely available, overall very stable and flexible and it's also a well documented platform with lots of options on both the hardware side (think components like graphics cards and sound cards) as well as on the software side (Windows 98SE and ME are popular, but Windows 2000 and XP will also work). Many interesting parts for Socket 370 based retro rigs are also very common , easy to find (and often cheaply), partially because of the universal AGP slot with with the newer Socket 370 boards are usually equipped. Socket 370 boards featuring ISA slots and Tualatin CPUs (with or without the use of an adapter) combined with an ISA sound card is a very popular build for many retro computing enthusiasts.Another pro about Socket 370 (and mostly because of the higher-end Coppermines and Tualatin-S's) is Pentium 3's relatively low power dissipation compared to it's performance, which has the added benefit that even todays PSUs will usually work with Socket 370 builds, unlike Socket A which requires strong 5v rails which modern PSUs often do not provide.
Slot 1 Celeron Game
Socket 370 is overall a very good platform for both beginners as well as the more experienced retro computer enthusiasts, though motherboards that support the latest incarnation of Pentium 3 (the Tualatin) are a bit more tricky to find as these started to get hit by the capacitor plague and because Tualatin entered the market as Pentium 4 was starting to sell, meaning Socket 370 boards which support Coppermine at the most are greater in number to begin with.