Regular Pentium had wider databus:

64-bit external databus doubles the amount of information possible to read or write on each memory access and therefore allows the Pentium to load its code cache faster than the 80486; it also allows faster access and storage of 64-bit and 80-bit x87 FPU data. *

486 had 32bit databus so Pentium Overdrive obviously had less pins than original Pentium and had to be designed differently in order to work

Custom chip with surface mounted voltage converter.

The Pentium Overdrive is not just an adapted Pentium. It is a unique design - a modified P54C core with double L1 caches, half-size cache line size and 486 external bus.

On late 486 motherboard, it actually runs faster than regular Pentium in many, roughly matching the P90 (pre-Triton Socket 5 mb).

A normal Pentium couldn't be easily adapted to 486 bus due to different cache line size (a cache line fill would require two burst reads which would be highly inefficient)

Here are some benchmarks of a pod83 running on a late 486 PCI board: So... I picked up a simple unassuming beige AT computer and it turned out to be this....

Ok thanks, I didn't realize it was a unique chip design, thought it may have been a standard Pentium core with some kind of socket/voltage adapter.

Another interesting fact about the OverDrive is how late it was released, October 1995 per Wikipedia. Whereas, Socket 7 processors was already out in June. I haven't looked but I wonder digging around in magazines around the end of '95 what a price comparison would be between an Am5x86 upgrade, a Pentium OverDrive 83, versus a then-soon-to-be-obsolete Socket 5 board and processor (perhaps used?).

Price drove the least common of ODP 83. People were hanging on 486 and few went to pentium machines but EDO and BEDO memory was so pricey then. Paid 700 cdn for pair of 8MB BEDO ram when I got FX version of Asus motherboard with Pentium 100. I had that in 96 if I remember correctly.

Cheers,

It was retailing for $299

For reference at about the same time, the Am 5x86 133 sold for $97, Cyrix 5x86 $130 ( 120 Mhz $160) and regular Pentium 75 about $190 (at volume quantities, the PODP was retail-only chip).

I think there is no surprise it wasn't a very popular chip.

Had it been released in 1993/94 as promised it would have been a killer. Even at that price.

I compared those chips here

Another thing that made the chip unpopular was that it didn't work properly with many older 5V only motherboards. I remember reading that Intel changed some specs at the last minute, so many boards that were built with P24T support before the POD was released didn't actually work (especially in L1 WB mode).

Perhaps the Pentium OverDrive should have been called an 80588 or a PentiumSX.