It's a CPU that easily let's you upgrade the performance of you system (they ran at double or triple the speed of the bus often called the external clock). The ODP variants had an extra pin that automatically disabled the soldered on CPU while the ODPR lacked the pin and were ment for upgrading socketed CPUs. The DX4 Overdrives contained their own voltage regulator so they could be run in boards that only allowed 5V CPUs (DX4 operated at 3.3V internally). There were also Pentium Overdrives for 486 systems but they weren't compatible with all 486 motherboards.

+1 for Kamerat's explanantion. Personally. I would left the overdrive installed. Games are so much more playable with it.
The i486 overdrive still has a true 486 core, I believe, but may compensates for the bottle necks of the Compaq motherboard.
Also that Compaq came with such an upgrade socket preinstalled, so it it a period-correct system anyway. 😀

more like oeuvredrive

Alright. So the Overdrive seems kind of cool!

So it is a true Windows 3.1 experience/system, right? I do want to leave it in there if it is, because without it, I'm pretty sure Duke Nukem would not run correctly 😜

I did some research and it has a 486DX core. Essentially it's an Intel 486DX 50 MHz with those extra features. Great for retro gaming... and word processing! 🤣

Ultrax wrote:

I did some research and it has a 486DX core. Essentially it's an Intel 486DX 50 MHz with those extra features. Great for retro gaming... and word processing!

Actually it's not a DX-50 but rather a DX2-50, since the overdrive runs on an external clock of 25MHz multiplied internally by 2 (hence DX2ODP50). A DX-50 has no multiplier and runs on a 50MHz external clock.

Other than that yeah, it's a regular 486 DX2. It is indeed period accurate for Windows 3.1. Duke Nukem 3D came out in 1996, so that's more like Pentium/Windows 95 era (even though it's a DOS game).

on lowest resolution it will work but won't be smooth, I tried it on my 486dx50 with 8m ram and it would get lag spikes, 16m ram made a difference but 50mhz wasn't good enough.

next I put in a overdrive dx4 100 but ran at 75mhz because I had a 50mhz crystal (split in half running at 25mhz) so 3 x 25fsb.
on 75 mhz it also wasn't that smooth

Finally I got a 66mhz crystal and put in a amd 5x86 133 cpu on a voltage regulator and upped the ram to 32m

duke nukem 3d runs 90% good on this setup high detail

tried it on my pentium 133 with 16mb and runs optimum

so your 50mhz will struggle. I suspect on a pci or vlb dx4 486 system it would prob run good, better then it runs on my 586 isa system, but since yours is dx50 and I suspect ISA only then bit out of luck

you can also type "dnrate" to see the frame rate

Given that the DX2-66 was probably the commonest 486 CPU (PC ownership skyrocketed during the 486-era, going from something few homes had when the first 486 appeared to pretty ubiquitous by the last ones), a DX2-50 is most certainly an 'authentic 486 experience' - although of course not an 'authentic 25MHz 486 experience'

DN3D runs nicely (well, about 25 fps) when I start it from within DOS, but when there are a lot of things going on at once it can dip down to 15 fps. It's still playable. And the occasional lag makes me feel like someone in the 90s trying to play Pentium-era games on the only computer they have - so that's somewhat special 😁

My friend's 425 has only its 25 MHz CPU in it, and from what I hear, DN3D is simply not playable. (Actually, almost nothing is playable on his because apparently his screen has a "flicker" issue)
I was going to give him the 33 MHz SX out of my destroyed Presario 433, but it was damaged so bad that the socket bent the pins when I took it out. 🙁

So bend them back...

So3 pins are big, robust and widely spaced. With a small knife or flat-headed screwdriver it's easy to bend them into place.

dionb wrote:

...small knife or flat-headed screwdriver...

Or a 0.5mm mechanical pencil 😀

I used a sewing needle on a over drive I rescued, spent 1 or 2 hrs and 1 pin broke off but luckily it was a outside pin which I soldered back and I rushed that one was definitely avoidable.

that cpu was really bad tho alot of the pins were mashed down.

if it was a socket 370 or 428 no chance

So370 is a pain, but can definitely be done, as can SoA. Even So478 could be possible, but given the platform never really interested me and those pins are sooo damn small and fragile - nope.