Cpu Adapters/Mods Compilation (SlotKets, etc)

[CHips]

I wanted to compile a list of known Adapters or similar, and speculate about what could Exist...
Post if you have seen some Existing Combinations missing here or thought non existent, or your opinion on whether an unknown Combination could be possible :p
Or just to share your experience using one of these

Format: Cpu Socket -> Motherboard Socket

Known Adapters

Socket 370 -> Socket 8: Extremely Rare, examples in some Japanese News, on Vogons
Socket 8 -> Slot 1: Very Rare, Asus C-P6S1 and few other Models, there are also Clones out there so could become easier to find, but no idea where the Project went since then.
Socket 370 -> Slot 1: ubiquitous... though Tualatin Capable ones like the PowerLeap PL-iP3/T are Rare.
Slot 1 -> Slot 2: Epox EP-S2C and one or some Others, Extremely Rare.
Socket 478 -> Socket 423: can occasionally be found, even here
Socket 479 (Pentium M) -> Socket 478 (Pentium 4): Very Rare Asus CT-479 (not working on many Motherboards), not aware of another Model
Socket 478 (Pentium 4) to Socket 775: something called "Socket 775 to 478 CPU Adapter"/PTCA-01, Extremely Rare. Notably used to test SL7QB/SL7Q8s here

Socket 5/7 -> 4, Unconfirmed

Not Adapters but Known Mods

Bga Pentium 2 -> Socket 370 like this Pentium 2 267
Modding Socket 771 Cpus to make these work on 775 is well known (the other way should be possible too I guess? but never heard of that since it is less interesting I suppose...)
Mods/Fakes of Mobile Pentium Mmx to Socket 7 are well known.
Core Gen 2-9 Mobile Bga to the respective Mobile or Desktop Pga Mods Exist (for example, QJR9s have been Modded to work on 1151)
There are some Mods to Run Intel Core 8xxx or 9xxx on 6xxx or 7xxx Motherboards

Atom -> 775 Mod appears to Exist, have yet to see some proof that it works.

Other similar known Upgrades or Oddities

486 on 386 Platform: RapidCad and some other Non Intel
Pentium on 486 Platform: Pentium OverDrive 63/83
Pentium 2 on Pentium Pro Platform: Pentium 2 OverDrive 333
Some AsRock Socket A Boards allowed you Upgrade to 754 via the 754Bridge
Some AsRock 754 Boards allowed you Upgrade to 939 via the 939CPU Board
There were also 939 Boards allowing Upgrade to Am2 via the AM2CPU Board (these also worked for Upgradeable 754 Motherboards it seems since they say "from socket 754/939 to socket 940(AM2)")
Sandy/Ivy Bridge 1155 on Nehalem/Westmere Platform: Intel SIBX_CRB (Prototype)
Nehalem/Westmere 1156 on Sandy/Ivy Bridge Platform: AsRock P67 Transformer
Crossflashing or Modding Bioses may make Broadwell work on 8 Series Chipset
Some Chipsets for consumer and mobile CPUs (H, Q, B, Z series etc) can run HEDT/Xeon E5 chips if the motherboard is designed around them

Supposed to Work without Adapter nor Mod (if Bios Compatible)

Socket 5 Cpu on Socket 7 Motherboard
Socket 603 on 604
Socket Am3 on Am2 or Am2+

Have not heard of those, some are silly or physically cumbersome and certainly do not exist but are probably possible considering existing Adapters or Platform Designs?
Assuming any fixable issues like missing Microcodes or Voltages are taken care of.

386 on 486 Platform?
Timna on Regular 370 or the other Way?
Socket 615 or Socket 479 (Pentium 3 Mobile) -> Socket 370: should be possible since Bga Pentium 2 -> Socket 370 Exists?
Socket 478 (Pentium 4) -> Socket 479 (Pentium M): why not since the other way is possible with the Ct-479?
Socket 423 -> Socket 478 or even 775: since 478 -> 423 Exists, so could the other way? And then, since 478 -> 775 Exists too, 423 -> 775 should be possible? And also the inverse directions? Let's Run Cedar Mills or even Pentium Ds on 423 Lol; getting Nx for Windows 10 or 11 Support on 478 or even 423 would be some Grail that have been pursued by some people!
Socket 479 (Pentium M) -> Socket 775: should be possible since we can do 479 -> 478 and 478 -> 775? Is there anyone in this world having both the Ct-479 and Ptca-01?
Atom -> 478/479 (Pentium 4/M) Interposer?
Socket A -> Slot A just like Socket 370 -> Slot 1? How come there are so many Socket 370 -> Slot 1 but nothing for the As?
Am2(+) -> Am3?
Slot 2 -> Slot 1?
478 <-> 603/604?
604 -> 603?
Other Mobiles Bga -> Mobile/Desktop Pga or Mobile Pga -> Desktop Pga?

Any theoretical possibility for these?
Assuming any fixable issues like missing Microcodes or Voltages are taken care of.

Anything between Socket A, 754, 939, 940 or Am2 besides these specific AsRock Boards? Something like the 478 -> 423 Adapters?
Anything between the 115x? Again as Adapters rather than Platform of Different Gen Chipset.
Am3 <-> Am4 <-> Am5?
Anything Else?

Should be Impossible.
or similar to recreating a whole Motherboard on top of the Socket, but that would be Cheating Lol

486 <-> Socket 4 or 5/7 ❌ 32 vs 64 bit bus
Socket 5/7 <-> Socket 8, 370, A, Slot 1 or A ❌ Bus signaling vastly different
Socket 370 <-> Socket 423 ❌ Bus signaling vastly different

[Wasmachineman_NL]

>I cannot find it anymore but I am pretty sure to have seen a Sandy Bridge work on 1156 (or was it the other way?)

Other way around, P67 Transformer. There's one for sale on Marktplaats right now actually.

[Glory_Cloud]

Interesting, I just pulled ten Slot 1 to Tualatin adapters from
some Dell Opt1plex PC's. I have seen the PL-IP3/T V2.0's
before but I am unfamiliar with the PS12437's. Is it a
PowerLeap as well? I don't see a manufacturer on it.
It has an Intel SL6C8 Celeron processor installed on it.

[xsecret]

[H3nrik V!]

IIRC there was some Celeron for socket 8 as well?

[crazybubba64]

I would expect most of the core 2 and mobile CPUs (Socket M, Socket P, etc. both soldered and socketed) to be able to run in an LGA775 board with the right theoretical adapter (good luck mounting a heatsink though). All of those used the same CPUIDs as their desktop counterparts and behave VERY similarly.

A lot of the limitations on laptops were imposed by the bus speed offered by the chipset and power budget. Most desktop boards are flexible enough that it shouldn't be a limitation really.

I'd expect it to be similar to the more modern mobile CPUs soldered onto LGA interposers.

[wren4777]

[cvandijk]

Do not forget the Slot 1 -> Slot 2 adapter like the Epox EP-S2C https://web.archive.org/web/20160304072212/http://www.anandtech.com/show/318

[CHips]

Cool, some nice replies, updated the first Post accordingly and added a few more theoretical combinations

Now I remember, it was that Topic from you Wren4777 that I thought about: https://www.cpu-world.com/forum/viewtopic.php?t=35789
I did actually misremember and thought that it was some Es Socket 1156 Sandy Bridge Cpu rather than a Gen 1 Platform with Socket 1155 Cpu (or the other way around as pointed by Wasmachineman_NL), but still interesting oddities!

Nice about the Atom on 775 Interposer, would take if there are some more Available...
Some Dual Core PineView like the D525 on 775 would be interesting for Benchmarks Vs Pentium 4/D or Core 2 on equivalent Platform rather than NetBook Vs Desktop or so...
And good replacements for the inefficient power hungry Pentium 4/Ds.
Considering 775 -> 478 should be Possible (since 478 -> 775 is), Atom on 478 should as well and would be really neat !

Have overlooked these Server Sockets and Slots, good find about the the Epox EP-S2C.
I guess 478 and 603/604 Platforms should be similar enough so some Adapter in the form of the 478 -> 423 or Ct-479 one would be possible...

[cvandijk]

There is different a slot 1 -> slot 2 converter (with a switch to select the cpu slot) on ebay, don't know the brand but here are the pictures:

[H3nrik V!]

The Celeron in Socket 8 has been described by Max1024 (or CPUShack) as well:

https://www.cpushack.com/2020/05/13/chapter-2-mini-mainframe-at-home-the-story-of-a-6-cpu-server-from-1997/

[CHips]

Well, that still counts as 370 -> 8...

Unless you meant some Socket 8 Celeron made like the Pentium 2 OverDrive, which I am not aware of and don't see anywhere in the Article.

[H3nrik V!]

[D.8080]

While browsing stuff I found this and asked the seller.

It's a socket 4 to 5 adapter.
Can't say if it is really that though.

[H3nrik V!]