AMD K6-II vs K6-III

Huge difference between the two. Lots more on die cache on the k62+, k63,k63+

They are harder to find as the k6III was mainly sold in laptops tho. Grab it if you can find it cheaply.

http://en.wikipedia.org/wiki/AMD_K6-III

They both suck. The K6-2 processor ran incredibly hot -- the computer store I worked at in high school custom-built some K6-2 machines, and despite the fact they had a monster of a heatsink on the proc and two case fans, the machines ran so hot that customers who didn't have air conditioning at home couldn't use them. They ran right on the borderline of overheating, so that if the ambient temperature was just a little too high, the machine would freak out.

A K6-3 is top of the line for a Socket7. It's do decent against an old P-II, but compared to any speedy P-II or any P-III (or even a Celeron) it'll start to show it's age.

"Suck" is probably a little strong, but as you note they were... tended to operate closer to their thermal limits then Intel CPUs of the time did.

Things to remember before shopping:

A: Honestly, you're not likely to see any real-world difference between the two. The K6-III would always beat the K6-2 by a "significant" margin on synthetic benchmarks which fit in its onboard cache, but the real world difference is a few percent at most assuming a motherboard with onboard cache. (Which basically any decent Super 7-capable Pentium board should have.)

B: If the machine you're thinking of upgrading has a non-Super 7 motherboard, which is basically a sure thing if it doesn't already have a K6-2 in it, it's probably a waste of time bothering, as you'll almost certainly need a voltage regulator module. (Some non-Super boards do have the 2.2v setting for the K6-2, but there's no guaruntees. You'll fry it if you stick it in a Pentium board that only supports the 2.9v core used by the original K6 and Pentium MMX.)

C: Older Pentium II/III computers are *really* cheap now, and for the most part are at least as fast as, more reliable, and more compatible with weird OSes then Super 7 machines.

Happy Hunting.

--Peace

The machine (MLB, crappy case, floppy, + some SCSI ISA cards) that I have has ASUS SP97-V motherboard in it. Officially only supports up to 233MHz (MMX chip is in it) but I found some information on the web some time ago stating that one could use K6-2 or K6-3 in it up to 450MHz. More specifically, I have a printout stating that 5.0, 5.5 and 6.0 are multipliers that are not found in the manual along with 2.2, 2.3, and 2.4V (it also shows how to set the jumpers to get those).
A separate website printout (sorry don't have location) (in german with header "ASUS Support Q&A Nr. 003") claims that SP97 series boards can use 75MHz frontside bus and the aforementioned 450MHz limits on K6-2 and K6-3.

But the bummer is that this MLB uses Simms (4 slots) which means that the memory is more expensive and more limited than if it used Dimms (or is it SDRAM?).

I'm just figuring out what is the cheapest way of building a half-decent machine (given what I have) to run Openstep and maybe get to some "use" out of it as a fileserver (storage really) or something like that. But if the Super7 may not be all that compatible with Openstep then I'll try it out first with the 233MHz MMX chip that is already in it

Recently I'm increasingly getting interested in restoring old hardware to run some of the older and discontinued GUI OSs. So this kind of goes together with my Quadra 950 - A/UX build and my planned BeOS, OS2, and 7100/66 - MkLinux projects.

Thanks all for the info.

IC

DIMMs don't have to be SDRAM, but usually they are. The old PCI PowerMacs and Ultra Suns used FPM and EDO DIMMs.

As for your mobo, if it doesn't take PC-66 or PC-100 DIMMs, I wouldn't even bother trying to use anything over 233MHz in it. Regular FPM/EDO runs at 16MHz. Even with a good cache, you'd have an effective CPU speed of just over 16MHz while waiting for all that data to get read into the cache from the slow RAM. Really, SDRAM DIMMs have a huge effect on performance over FPM/EDO. The big cache, system bus speed (100MHz) and good RAM (PC-100) make a K6-III run well. If you remove any of those, you create an instant bottleneck. Effective speeds can be created by disabling all cache on the system. That way it all runs straight out of RAM. You'll see just how slow it really is. Do the same on an SDRAM system witht eh same CPU and you'll be able to tell for sure.

Googling your motherboard model number ( ASUS SP97-V ) turns up this:

http://www.cheek.org/tech/009.htm

Rock! ;^>

--Peace

Wow. I recognized the picture of the main board box. I have an ASUS SP97-V box. I'm pretty sure I don't and have never had an SP97-V. It probably came to me with other parts in it, but that was a slight revelatory moment when I realized I already knew what the box looked like.

Not spending a dime on this. Thanks Jon for keeping me from throwing the money away. I'll try getting Openstep to run on the thing as it is (or will be, 3GB HD, SCSI card and a SCSI CD-ROM). If it looks interesting (which it will) I may go to the local university surplus and pick up something worth while to run it on.

Thanks again,

IC

I just sold a K6-3 that wouldn't work on my motherboard, I wanted a small rack system that didn't need a fan (A K6-3 at 400 with 1.7 volts doens't need a fan to run)

I tested its on another board and it ran fine at 600MHZ (100FSB*6). Like someone else said though, I can sell you a Pentium 3 for just about the same as a new K6-3. Or get an old mac and run Virtual PC on it. I'm doing that right now, it's amazing to see Win98 boot on a Beige Mac!