Checking https://www.ardent-tool.com/CPU/486_Step.html it says both are 5 volts. Exactly which DX4ODP100 are they, what are their S-Specs?

I am also wondering about the L1 cache size, I suspect it's 16KB, but have never has this confirmed. If you get NT4 or W9x running on them please will you check?

On way is to use my SIV utility, it will measure the L1 cache size on start-up and also has the [Cache-0 Latency] panel. Notice the big jump from the 16KB time to the 24KB time.

red-ray wrote on 2026-02-22, 20:18:

Checking https://www.ardent-tool.com/CPU/486_Step.html it says both are 5 volts. Exactly which DX4ODP100 are they, what are thei […]
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Checking https://www.ardent-tool.com/CPU/486_Step.html it says both are 5 volts. Exactly which DX4ODP100 are they, what are their S-Specs?

I am also wondering about the L1 cache size, I suspect it's 16KB, but have never has this confirmed. If you get NT4 or W9x running on them please will you check?

On way is to use my SIV utility, it will measure the L1 cache size on start-up and also has the [Cache-0 Latency] panel. Notice the big jump from the 16KB time to the 24KB time.

I think you misunderstood the issue, one is ODP, other is ODPR.

fsinan wrote on 2026-02-22, 14:50:

I'm a bit confused. DX4ODP100 is different from DX4ODPR100 with an extra pin for deactivating the soldered on board 486 cpu. OK […]
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I'm a bit confused. DX4ODP100 is different from DX4ODPR100 with an extra pin for deactivating the soldered on board 486 cpu. OK.

But can we use it on a normal 5V socket2?

And normal more modern regulator included 3.3V socket3 board? with DX4-100 settings?

Best Regards.

I have a DX4 ODP upgrade in my IBM 2168-552, that is socket 2 5v

https://theretroweb.com/motherboards/s/ibm-ps … a,-2168a-type-1

Never had an overdrive, however, as I understand the DX4 overdrive’s whole point is to be 5V capable to upgrade the slower and older 5V 486 on old boards.

fsinan wrote on 2026-02-22, 14:50:

I'm a bit confused. DX4ODP100 is different from DX4ODPR100 with an extra pin for deactivating the soldered on board 486 cpu. OK.

But can we use it on a normal 5V socket2?

Yes, if you remove the extra pin so it'll fit*

And normal more modern regulator included 3.3V socket3 board? with DX4-100 settings?

Best Regards.

Yes, it should take 3.3V input as well. Again, the pin needs to go*

*No guarantees. But it should.

Socket 1/2/3 all support 169 pin CPUs without removing a pin....

The ODP should work in a normal motherboard that does not have an existing CPU to disable. The pin would not be connected to anything...

Some motherboards that need to disable the onboard CPU have a jumper instead, and do not rely on the 169th pin.

It's only incompatible with very old 168 pin sockets. Motherboards that only support 3-4v CPU voltages are incompatible because the ODP's linear voltage regulator has a drop and needs 4-5v minimum to start.

MikeSG wrote on 2026-02-23, 15:36:

Socket 1/2/3 all support 169 pin CPUs without removing a pin....

Have you tried it? Some sockets have allowance for it because they are specifically dual purpose, and some old ones are so thin it happens to fit, but it's keyed to not fit.

MikeSG wrote on 2026-02-23, 15:36:

Socket 1/2/3 all support 169 pin CPUs without removing a pin.... […]
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Socket 1/2/3 all support 169 pin CPUs without removing a pin....

The ODP should work in a normal motherboard that does not have an existing CPU to disable. The pin would not be connected to anything...

Some motherboards that need to disable the onboard CPU have a jumper instead, and do not rely on the 169th pin.

It's only incompatible with very old 168 pin sockets. Motherboards that only support 3-4v CPU voltages are incompatible because the ODP's linear voltage regulator has a drop and needs 4-5v minimum to start.

Thats what I thought according to my search. When the cpu arrives, I will try immediately.

you can drop ODP into regular socket..
Most system works fine with him.

(checked with DX2ODP66 and DX4ODP100)

The ODPs should be 487sx pin compatible. If you’re having issues, you can try setting up your motherboard for that setting if present.

I've successfully used a DX4ODPR100 processor in Socket 1, Socket 2, and Socket 3 systems.

Even some strange ones like the Alaris COUGAR 486BL and Tekram G486PLB-3

Never had an issue.

Or were you asking if a DX4ODP100 with the extra pin could be used in Socket 1, Socket 2, and Socket 3 systems ?

douglar wrote on 2026-02-24, 15:14:

I've successfully used a DX4ODPR100 processor in Socket 1, Socket 2, and Socket 3 systems. […]
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I've successfully used a DX4ODPR100 processor in Socket 1, Socket 2, and Socket 3 systems.

Even some strange ones like the Alaris COUGAR 486BL and Tekram G486PLB-3

Never had an issue.

Or were you asking if a DX4ODP100 with the extra pin could be used in Socket 1, Socket 2, and Socket 3 systems ?

Ofcourse I'm asking for ODP. ODPR works on regular motherboards. Question is answered above.