Is that the K5 cpu? It's a pentium compatible, so I guess socket 5/7.

Here's the top

http://www.cpu-museum.de/?a=i&f=f&s=l&id=0010 … P75+75MHz+front

It's different from the top of any K5 I've ever seen.

Here ( http://en.wikipedia.org/wiki/AMD_K5 ) it says : There were two sets of K5 processors, internally called the SSA/5 and the 5k86, both released with the K5 label. The "SSA/5" line ran from 75 to 100 MHz (5K86 P75 to P100, later K5 PR-75 to PR100); the "5k86" line ran from 90 to 133 MHz. However, AMD used what it called a PR rating, or performance rating, to label the chips according to their equivalence to a Pentium of that clock speed. Thus, a 116 MHz chip from the second line was marketed as the "K5 PR166".

However it's a little strange if the 5k86 range is between 90 and 133, and that picture of yours has a 75MHz model....

[removed wrong assumptions 😉]

Edit: Ok I reread some stuff, so the 5x86 is a fast 486 core CPU (with 16 kB L1)
while the SSA5 / 5k86 / K5 is a completely new core.
( http://www.sandpile.org/impl/k5.htm )

I think the K5 is completely different from the 5X86. The latter is still a 486 while the K5(isn't that codename supposed to mean Pentium Killer :p ) is a pentium compatible chip. I notice also that the ssa/5 K5s are all of them PR rated, but that number is equal to the actual cpu speed. And now I see that the original pic that sliderider posted is indeed an ssa/5 model, so it's not strange after all that it runs at 75MHz.

Markk wrote:

Here ( http://en.wikipedia.org/wiki/AMD_K5 ) it says : There were two sets of K5 processors, internally called the SSA/5 and the 5k86, both released with the K5 label. The "SSA/5" line ran from 75 to 100 MHz (5K86 P75 to P100, later K5 PR-75 to PR100); the "5k86" line ran from 90 to 133 MHz. However, AMD used what it called a PR rating, or performance rating, to label the chips according to their equivalence to a Pentium of that clock speed. Thus, a 116 MHz chip from the second line was marketed as the "K5 PR166".

However it's a little strange if the 5k86 range is between 90 and 133, and that picture of yours has a 75MHz model....

But are 5K86's really K5's? The only K5's I have seen say K5 on them like the ones below.

I know. Up to now I also had seen only the K5 cpus. But if what it says over there at wikipedia is true, then there are 2 different series, and their difference is that the 5k86 uses the pr rating, but runs at the same speed, and the other one runs at a slower speed than it's pr rating.

edit : you can read here, too : http://www.pcguide.com/ref/cpu/fam/g5K5-c.html

There are two cores. The older chips don't have a fully completed design and perform slower which is why the PR rating equals the clock speed.

But they are mostly the same CPU. If they could have managed more clock speed they would have been excellent competition but they topped out quickly and were late to market.

swaaye wrote:

There are two cores. The older chips don't have a fully completed design and perform slower which is why the PR rating equals the clock speed.

But they are mostly the same CPU. If they could have managed more clock speed they would have been excellent competition but they topped out quickly and were late to market.

Kinda like Cyrix, except Cyrix managed to keep up a bit better then AMD in those days