Intel i486 DX33

Built in the 15th week of 1991, this is an early 486DX33. At that time, a 386 running at 25MHz or 33MHz was considered a modern PC. The 286 was already low-end and the 486 was high-end. Interestingly, the 486 logo lacks the DX suffix because the 486SX hadn’t been released yet. The first SX CPUs appeared in mid 1991 (I have one dated 21th week of 1991: i486SX-20. However, in the specification on the CPU it does already mention A80486DX-33. The earliest 486 CPUs (dated 1989) don't even mention DX at all.

In early 1991, this CPU offered ample processing power for most users, even though technology was rapidly advancing. Just a year later, in 1992, the 486DX2/66 was introduced which was twice as fast as the DX33. These were great systems back then, but unfortunately, VESA Local Bus (VLB) wasn’t available yet, so you’d be stuck with the slower ISA bus. For graphics-intensive applications and, especially games, the VLB bus truly made a difference on a 486.

The 486DX features an integrated floating-point unit (FPU) that significantly speeds up applications like CAD and spreadsheets. However, in most mainstream applications and games that run well on a 486, the FPU isn’t particularly noticeable. Running Doom or Windows 3.1 with or without the FPU doesn’t make a practical difference. 486s with the SX designation don’t have the FPU enabled.

In the 386 line, the DX and SX designations have different meanings. DX indicates a 32-bit external bus, while SX refers to a 16-bit bus. Despite this, both CPUs are internally 32-bit and neither features a FPU. In most cases, you can install a separate FPU in a dedicated socket.

A similar processor has been benchmarked! Click here to see this processor and the benchmarks.