Socket7 couldprovidedualvoltage to the CPU via a split
rail.Thesocketsareotherwisebasically the same, to the
pointwhereyoucouldputa Socket 5 CPU in a Socket 7
motherboardandit wouldrunfine.Chipsetchoices
ThiswasbeforeAMDmadeitsown chipsets, but there
werestillplentyofoptions.If you wanted the best
compatibility,yourbestSocket7 option was Intel’s Triton
series,whichpeakedwiththeTriton 430TX in 1997. The
430TXsupportedeithera 60MHz or 66MHz front side bus,
andalsogaveyoutheoptionofthree types of memory –
fastpagenon-parity,EDOandSDRAM, with the latter two
options coming in the brand
new DIMM form factor. This
led to many motherboards
coming with both DIMM
slots and the older 72-pin
SIMM slots.
However, your choice
wasn’t limited to Intel
chipsets. Plenty of third-party chip makers, including VIA,
ALi, SiS and Opti had their own Socket 7 chipset options.
For the most part, they held up pretty well, and they were
usually cheaper than genuine Intel boards, but there were
also sometimes compatibility problems. As an example,
when I worked in a computer shop in the late 1990s, we
often had problems with ALi-based motherboards not
working with the 32x Samsung CD-ROM drive we stocked.Is it a bird, is it a plane? No, it’s Super Socket 7!
Intel pulled the plug on Socket 7 after the Pentium MMX,
and instead moved its Pentium II CPUs to the new Slot 1
format (see Issue 200, p107). In the meantime, it settled on
ATX as the motherboard and PSU standard for Pentium II.
There were some ATX Socket 7 motherboards, but
most of them used the older AT form factor, which split the
main power socket into two parts and only had a (large DIN
socket) keyboard output fixed to the board as standard –
the rest of the ports all connected to the motherboard with
ribbon cables.If you used an AT power supply, you also had to physically
switch off the PC after use, as it couldn’t be shut down
with software. Again, though, this was a strange crossover
period, and there were motherboards that conformed to
the AT form factor, but which also had both AT and ATX
power sockets.
While Intel was busying itself with ATX and Slot 1, though,
AMD and its chipset partners went all out on Socket 7. The
result was Super Socket 7, which maintained compatibility
with older Socket 7 CPUs, but also supported AGP graphics
cards and could clock the front side bus at up to 100MHz.
There was also a range of Super Socket 7 motherboards in
both ATX and AT form factors.
Super Socket 7 was great for cash-strapped enthusiasts,
as it meant you could keep most of your old PC – the PSU,
case, hard drive and even the memory in many cases; you
just needed a new motherboard and CPU if you wanted a
decent upgrade. It was massively cheaper than upgrading
to Pentium II.
You could run a Pentium CPU in a Super Socket 7
motherboard too, or a Cyrix M-II or IDT WinChip 2, but what
you really wanted was an AMD K6-II or K6-III. AMD’s last
Super Socket 7 CPUs really pushed the limits of this old
socket and the AT era, with the 100MHz front side bus
often making these systems faster than the 1st-generation
66MHz Pentium II CPUs, while costing much less money.
The K6-III even pushed the clock speed up to 550MHz, and
integrated 256KB of L2 cache onto the die.End of an era
AMD finally moved to its own Slot A platform with the first
Athlon CPUs, as well as introducing the Ironbridge chipset
under its own brand, before it discontinued the K6-III at the
end of 2003, eight years after Intel first launched Socket 7.
Meanwhile, Cyrix was bought by VIA, which later produced
a few CPUs for Intel’s Socket 370 platform, as well as its
own embedded EPIA platform. But the days of multiple
CPUs being supported by one socket are now over – the
mainstream desktop PC market has since been mainly
dominated by just Intel and AMD using their own CPU
dedicated sockets.Socket 7 supported
CPUs from multiple
manufacturers,
including Intel,
AMD, Cyrix and
IDT. Photo credit:
Konstantin Lanzet
THE K6-III EVEN
PUSHED THE
CLOCK SPEED UP
TO 550MHZ