David Hayward recalls an awesome processor
Moving up from an Intel 386 SX-25 to the utterly amazing Intel DX2-66 was one of the most powerful leaps in computing I've ever experienced; save for, perhaps, a Spectrum 48k to Atari ST. The DX range of processors were a quantum leap forward in desktop computing. The 386 DX had doubled the transistor count from the old 286, quadrupled the MIPS performance across the board and brought true 32-bit processing to the desktop masses. The memory address range was also vastly improved; up to 4GB of RAM or 64TB of virtual memory in protected mode - numbers considered almost too high to comprehend back in the 90s. The 486 DX was the first processor to feature a built-in Math Co-Processor and the first processor to finally break the one million transistor barrier.
The DX2-66 was the ultimate in gaming processors. It was fast, had an extra 8KB of on-chip cache and was priced just right for early DOS gamers to enjoy the benefits of an amazing gaming setup, where the likes of Doom and X-Wing ran beautifully.
History
The first of the 486 range of processors was introduced late in 1989, with the vast majority of the PC desktop world really getting to grips with the new line by the first quarter of 1990. The performance of the 486 was a vast improvement over the previous 386 processor range, and when used with the improved graphics cards, memory and hard drives of the day, combined to make a system that was unparalleled in the computing world outside of a university computing lab or research facility.
The first 486-DX chips ran at 20, 25, 33 and 50MHz without the clock doubling, then within a year or so a 486-SX version appeared, at a lower cost but with the floating point element missing or disabled. By mid-1992, the classic Intel 486 DX2-66 was launched, with slightly improved versions the following year.
The clock speeds further increased, until around 1994, when the DX4 range was introduced. The DX4 ran at triple clock rates, allowing a base clock speed of 100MHz and featuring either write back cache or write-through cache depending on the model.
Finally, though, the public warmed to the Pentium which was released in 1993. The first batch of Pentiums hadn't been received too positively, having been shown to have had some issues with gaming and, in some instance, a faulty floating point. By the time the second generation of Pentiums were available, however, the old DX range were long gone and developers were already taking advantage of the newer and more powerful processors.
The Good
At the time, this was the top of the range in terms of gaming and a blisteringly fast processor compared to what came before.
The Bad
Although I can't ever recall experiencing this, there were reports of the cache causing problems in some games, most notably Wing Commander.
Conclusion
The 486DX2-66 was a great processor and one of the first CPUs where we actually chose as part of a home built system over the previously more popular off the shelf varieties.
It was the start of PC computing for a lot of us, as well as higher end PC gaming in general. It soon became the holy grail of ownership; to say you had a DX2-66 inside your machine as you typed in the command to run Doom, while your friends looked on with an envious eye, was what it was all about.
Did You Know?
• The AMD version, the AM486 DE2 and DX2-66 was much cheaper than the Intel DX2-66, but it didn't perform quite as well.
• The 486 DX range introduced Pipelining, which was previously only reserved for mainframe computers.
• Intel had a choice of either running with the 486 range of processors or its new concept i860 RISC processors. Compaq pressured Intel to run with the 486, while, interestingly, Microsoft pressured Intel to put all its effort into the i860.
• The move from an SX-25 to a DX-66 alllowed Wolfenstein to look better than ever.