[bombcar]

I remember arguments (and benchmarks) around all the variations of the 486 since the bus speed/clock speed was uncoupled (the /2 is clock doubling). For some applications, a 50Mhz 486 with a 50Mhz bus would beat a DX/2 66Mhz with a 33Mhz bus.

And sometimes the DX/4 100Mhz would be slowest of all those at 25Mhz bus.

[Sheeplator]

Nearly correct. The DX/4 100MHz had a 33MHz bus. The DX/4 75MHz had the 25MHz bus. I remember well because I had both.

[bombcar]

Now I remember being annoyed that it wasn't the DX/3 as it should have been!

[einr]

Especially since when actual clock quadrupled chips eventually came out they had to call themselves ridiculous things like ”5x86” instead of DX/4. (The Am5x86 133 runs at 4x33 MHz)

[cout]

I think 5x86 had more to do with marketing than anything else, because the Pentium had already been on the market for a while when the Am5x86 came out.

[einr]

I think it’s a bit of both. It absolutely tried very hard to pretend that it was a ”586” (Pentium class) but also ”5x” is right there and implies that if the DX4 is 4, this is 5.

The full name on the chip on some of them is ”Am5x86-P75 DX5-133” which implies a lot of things, some of which are flat out misleading (it does not get very close to ”P75” performance)

[Zardoz84]

I had one of these back on the day. A very fine 486

[saltcured]

I remember being so excited when I figured out how to jumper my DX/4 100 and operate it with clock doubling and a 50 MHz front side bus speed. Same core speed, faster memory and I/O.

My peripherals seemed to take it. My graphics output showed some slight glitches, which I was OK with for the speed.

However, I think it was a bit unstable and would fail a correctness challenge like compiling XFree86 or the Linux kernel, which were like overnight long runs. Must have been some bit flips in there occasionally. I seem to recall that once that reality settled into my brain, I went back to the clock tripler config.

[bombcar]

I still remember scribbling on Athlons with a pencil to max them out - we probably spent as much on heatsinks as we saved on CPUs.