Pentium III

Posted on July 10th, 2011 in Prehistory

The Pentium III architecture was released in 1999. As far as I know, the first processor was clocked at 400 MHz, with 100 MHz FSB, of course – 133 MHz FSB was introduced later.

There wasn’t much of a performance increase when users went from the 60/66 MHz FSB of the Pentium Pro architecture to the 66/100 MHz FSB of the Pentium II architecture. They could have made 100 MHz FSB Pentium Pros with simply higher speeds just fine. The Pentium Pros were, however, more expensive to make than the Pentium II. I read that’s because the L2 cache was “external,” i.e. separated from the processor’s core. The Pentium II had it integrated and a new package was released: Slot 1, officially called SECC (Single Edge Contact Cartridge). Having it separate from the core was more expensive in terms of manufacturing costs.

So the Pentium II was simply a better and cheaper to make Pentium Pro. Well, for the typical user, anyway. The Pentium Pro supported multi-processor configurations, while the Pentium II did not. You could have a machine with two Pentium Pros (and I think even four), but you couldn’t have a machine with two Pentium IIs. The point is that most people didn’t want one anyway.

Here’s where the Pentium III was undoubtedly better: Streaming SIMD Extensions, or SSE. This is a great improvement for floating-point calculations. The biggest benefactor from these is 3D graphics, which was hot new stuff back then.

I remember people weren’t very enthusiastic about the new Pentium III, since it didn’t exactly look like a great improvement over the P II. The latter was released in 1997 and the P III in 1999 (the Pentium Pro, by comparison, was made between 1995 and 1998). Some people may have had their BS meters topped. Intel’s arch-rival AMD was trying hard to compete by offering good performance and cheaper prices.

But the P III processors were good and they can still be used even today for some routine tasks. An old Pentium III system, provided it has enough RAM, can still do internet surfing, office applications, etc. Like with any technology, most people mostly bought averagely clocked models: 700, 800, maybe 933, sometimes 1000 MHz. And there were also the cheaper versions, the Pentium III Celeron models, which were the annoying crap products that everybody chose just so that they can brag about having a more “premium,” Intel system. A lot of people chose these over the “full” P IIIs and then wondered why AMD’s offerings were cheaper or equally priced and performed better. The reason was obvious: if you wanted something good, you had to be prepared to pay for it. But this is a problematic mentality still encountered worldwide: everyone wants the mediocre model from the premium range. Intel’s “failed Pentium III chips that were re-engineered as Celeron,” as a friend described them, provided the perfect opportunity for that.

At some point, Intel decided that the Slot 1 packaging could also be made cheaper, and released the Socket 370, officially dubbed FC-PGA (Flip-Chip Pin Grid Array). In order not to force people to get new motherboards, they continued to make both Slot 1 and Socket 370 versions of the Pentium III.

In the meantime, Intel was also making processors for pro users. Those were dubbed Xeon (the name is still used today, for the latest pro-oriented models) and there were Pentium II Xeon models and Pentium III Xeon ones. All of them used a cartridge-like physical interface, the Slot 2 (of course, the official name was SECC 2). They were meant to be a better version of the consumer-oriented models and the Slot 2 motherboards always supported more and faster features.

This is where it gets interesting. Intel decided to also adopt the cheaper-to-make package for the Xeon models. They had released the first Pentium 4 with a new Socket 423, clocked at 1.3 GHz, marketed to have 400 MHz FSB. It actually ran at 100, but the transfer rates could be four times the speed of the bus because the data transfer was quad-pumped.

Their Pentium III Xeons, when moved to pin grid array packaging, were no longer called Xeon, instead just Pentium III-S. The new socket looked identical to the Socket 370 used in the consumer market, but the processors weren’t compatible with each other’s sockets. The new socket was dubbed FC-PGA2.

The consumer Pentium III models were, at that point, somewhat respected because of their core dubbed Coppermine, which was a good performer. The new, FC-PGA2 processors for the pro-user had a new core developed, called Tualatin. The Tualatins were only supposed to work on special FC-PGA2 motherboards, but some companies made adapters so that you could use a newer Tualatin in your old Socket 370, FC-PGA motherboard. There were also adapters made for Slot 1 motherboards and even some rare models made for Slot 2 motherboards.

All of a sudden, everyone could use the new Tualatins in their older systems. These processors performed exceptionally well, but the marketing was attracting attention towards the new Pentium 4.

A little note: during the Pentium II and Pentium III era, everyone, including AMD, made use of SDRAM (Synchronous Dynamic Random Access Memory). This kind of RAM had been around for a while, at least since the 66 MHz FSB Pentium II. It ran at 66, 100 or 133 MHz and usually, the computer’s FSB speed was the same.

Well, when the first Pentium 4 and the first Tualatin Pentium III were released, newer and faster RAM technologies were also released. Intel went for RDRAM, developed by the Rambus company (which is what the first R in the acronym stands for), while AMD went for DDR SDRAM (DDR stands for Double Data Rate). Of course, there was a big battle over what is better. RDRAM only works in dual-channel, so they always named it with double the actual speed it was working at. The best RDRAM known to people was PC-800, working at 400 MHz. That’s also the top speed of the first DDR standard. However, it seems that Rambus didn’t stop developing RDRAM and made even faster versions later. But, by then Intel had already abandoned RDRAM and also moved to DDR.

The battle between DDR and RDRAM was, of course, a popularity battle. RDRAM was expensive, DDR was cheaper. You always had to buy RDRAM in pairs, too. You couldn’t just add more RAM easily, like you could with DDR. If the motherboard had four RAM slots and you decided to start with 256 MB with the thought of upgrading to 512 MB later on, you had to buy two sticks of 128 MB and then another pair of 128 MB.

DDR was much simpler – just like a faster version of SDRAM. You could add memory at will.

The Pentium III architecture had been limited to SDRAM, up to this point. Intel silently made the 840 chipset, thus giving RDRAM support to the Pentium III. Such motherboards were rare enough – I have seen one for the Slot 1, supporting one processor only, and two that were built for dual-processor configurations (one with dual FC-PGA sockets, the other with dual Slot 2).

However, if one managed to fight through the general obscurity of these technologies and also managed to procure the necessary adapters, one could have a single-processor Tualatin with RDRAM, or dual Tualatin with RDRAM, which is the fastest configuration of Pentium III ever made possible. Again, during all this, marketing was pushing you to buy the Pentium 4 or the Athlon and Athlon XP, AMD’s offerings. The fastest Tualatin was clocked at 1.4 GHz and had 512 KB of L2 cache.

The kicker is that this hard-to-get Pentium III configuration appears to outperform all the socket 423 Pentium 4 processors, up to 1.7 GHz (that was reported by a Upgradeware, a former company who made FC-PGA2 socket adapters). That’s when the new generation of Pentium 4 processors was released, along with the new Socket 478. The dual processor Tualatin configuration is even better, but there were only two motherboards that could do this and they both needed adapters for FC-PGA2.

 The Tualatin Pentium III at 1.4 GHz, or maybe all the Tualatins, were the first Intel processors to have the previously exposed core covered with a metal cap, for added resistance both thermally and mechanically. The Socket 423 Pentium 4 models looked similar.