Pentium Pro question

[rommelrommel]

Hey, I need a Pentium Pro for the second processor in my folding rig. The markings on my processor now are:

KB80521EX200

SL254 256K

L7220529-0321

From what I gather the bold numbers there are the important ones. I need a:

200 mHz 256K cache Pentium Pro with stepping SL254

Now, I've had it suggested that steppings one different may be compatable in dual processor systems, ie: SL253 or SL255. Can anyone shed any light on that?

Thanks!

 

[AndyHui]

Although Intel does not recommend it, mixed stepping SMP is possible for the Pentium Pro. You should NOT use mixed steppings in a 4-way system.

You have an SB1 0x619 stepping SL254. The following S-Specs are compatible for mixed stepping SMP: SL22T, SL22V, SL23M, SL255.

There is no SL253.

I've left out the SA1 0x617 stepping processors. Intel indicates the mixing these are OK as well, but I would avoid it.

 

[SoundBoy]

Actually, intel does recommend mixed steppings, but they can only be one stepping apart. It might even be possible to find it on intel's site. Pentium Pro > errata.

 

[AndyHui]

Read the specification update. Mixed steppings are NOT recommended, although they are possible.

There is also no requirement that they be only 1 stepping apart. As long as the processor has the same family and model number, SMP may be applicable based on the mixed stepping SMP matrix.