Intel 486 Overdrives - SX with an FPU or not?

[CPUShack]

Here we see that the SX2 overdrive has an FPU integrated.
http://www.cpu-world.com/CPUs/80486u/Intel-SX2ODP50.html

Technically I think it does, but it is not enabled.
see the markings on OD boxes:
http://screencast.com/t/BNbZZmcY3Wz
http://screencast.com/t/tncZa42Mn

Clearly the SX2 does NOT have the FPU enabled

Same with earlier Overdrives

Also other then SL-Enhancements, what other differences are there between a ODP486DX33 and a DX2ODP486DX66

BOTH are based on DX2 architecture (according to the datasheet anyways)

[H3nrik V!]

As I understand this:

http://chookman.id.au/cpu/processors/Overdrive/overdrive.html

ALL overdrives are DX, DX2 or DX4 - all with the FPU enabled, and the "SX" actually is to tell the buyer, what processor it upgrades.
Again, as I understand it, they changed the naming at some point in time to avoid confusion of whether or not the overdrives had FPU or not.

[H3nrik V!]

Well, I do agree that your second images seems like there is no FPU.

Could you post an un-cropped version of the box?

[CPUShack]

yah can do
Here we see that the V3 of the original ODs added SL Enhancements
http://web.archive.org/web/20000818070147/http://support.intel.com/support/processors/overdrive/intel486/8518.htm

so V3 and the DX2ODs must be fairly similar
DX2ODPs were P23T core, not sure how that compares to the P24 and P24Ds

[CPUShack]

http://screencast.com/t/TZ8XAAcpzOjI

[CPUShack]

[Chook]

The few SX ODs that I have tested show up as a DX2 in the POST screen. I have not tested further.

Is the difference between the DX2ODP and the normal DX2 the multiplier? The ODs are designed to be just dropped in without having to change any jumpers or settings. I don't think you can do that with a normal DX2. I haven't tested whether the ODs have a fixed multiplier.

I thought that there is no difference between V3 ODP486DX and V3 DX2ODP. Intel just decided to change the marking system - as I wrote on my own Overdrive site. Its all speculation though as I have not confirmed any of it.

I would like to know what the V numbers indicate.

[Chook]

Ok, you got me curious now! I have pulled out my 486 mobo and tested my chips. The ODP486SX chips report as DX2 with co processor installed, but the SX2ODP50 shows up as SX2 with coprocessor not installed. The ODP486-33 Q695 reports as a DX2.

The board doesn't seem to like PGA169 cpus so I used a interspacer without the etra pin.

I'll have to get a hard drive and operating system to test them further.

[CPUShack]

interesting the SX shows as a FPU and the SX2 doesnt lol

V3 ODP and V2 DX2ODP are very likely the same

V4 DX2ODP maybe they changed the cache to WB (like the DX4ODP)

[H3nrik V!]

Well, maybe - the SX one is named as according to Chook's webpage (it would make NO sense at all to have an SX overdrive - what would you upgrade from?)
However an SX2 makes perfectly sense, as it doubles the speed of an SX processor equipped system.

[CPUShack]

ALL overdrives double the clock
SX20 overdrive runs at 40MHz for example

[H3nrik V!]

[Chook]

From my basic testing it would appear that when Intel changed the numbering system, they also introduced actual SX Overdrives. So the only upgrade you would get from a SX2ODP50 is double the clock speed. Looks like few people thought it worthwhile as they are rather rare.