If someone finds a box of thousands of these, then I'm sure it will be enough for everyone 😀 Till then you should have luck or/and a very deep pocket.

SnipeUout, you could consider AMD X5-P75. I think it's easier to find although its performance is not so bad.
486 DX4 vs Cyrix 586 vs AMD 5x86

vetz wrote:

The AMD X5 P75 133mhz can be overclocked to atleast 160mhz. If you're lucky and a have a 486 PCI board it may also run at 3x60 (180mhz). At that speed it minimum equals a Cyrix 5x86 133mhz and the POD at 100mhz.

I'd say an AMD 5x86-X5-133ADZ is the most affordable high performance 486 solution. You can glue a heat spreader to it and run without active cooling even with some overclocking like 4x40MHz or 3x50MHz.

Recent Voodoo-based gaming results shed a new light on the Cyrix 5x86-133 stacked up against the Am5x86-160. Voodoo 1 vs. Voodoo 2 on a 486

Bang for buck, go with an Am5x86-133 and run it at 160 MHz. Only in GLQuake and GLHexen2 did the Cyrix 5x86-133/4x come ahead of the Am5x86-160. In other games, the 160 won.

What is your intended gaming target for this system?

If you want to dump $1000, you might be able to find a CPU-world collector willing to sell you their Cyrix 5x86-133/4x. The advanced features of the Cyrix 5x86 chips are neat to play with. If you like the appeal of some next generation features in your 486, you can also try for a Cyrix 5x86-120. Because of the 40 MHz PCI bus these chips run at, they keep up with the Cyrix 5x86-133/4x in games.

The Cyrix 5x86-133 was never easy to find.
However, there was a lot of CPU collecting going on even when 486 was considered just slow old trash.

An overclocked AMD 5x86-133 may be a good alternative, as would a POD.
And finding a (working) board that will work with any of these CPUs might be a challenge on its own.
But it can be quite challenging, getting an optimal rig together.

How much do the Cyrix 5x86-120 CPUs normally go for nowadays? I would kinda like to get one, but don't want to overpay when/if I do find one.

cyclone3d wrote:

How much do the Cyrix 5x86-120 CPUs normally go for nowadays? I would kinda like to get one, but don't want to overpay when/if I do find one.

I've seen some go for IIRC $20-30 on collector's sites recently.

POD is a good choice, since it can work with many old 5V boards. Not cheap though. But AMD is much more practical.

feipoa wrote:

Recent Voodoo-based gaming results shed a new light on the Cyrix 5x86-133 stacked up against the Am5x86-160. Voodoo 1 vs. Voodoo 2 on a 486

Bang for buck, go with an Am5x86-133 and run it at 160 MHz. Only in GLQuake and GLHexen2 did the Cyrix 5x86-133/4x come ahead of the Am5x86-160. In other games, the 160 won.

Sounds like the old FPU (Quake engine) vs ALU (everything else in those days) thing.

stamasd wrote:

cyclone3d wrote:

How much do the Cyrix 5x86-120 CPUs normally go for nowadays? I would kinda like to get one, but don't want to overpay when/if I do find one.

I've seen some go for IIRC $20-30 on collector's sites recently.

Usually they go for 40USD and up. This is for untested CPUs.

Last one sold for 30USD and it was kinda mistake by the seller. Never seen any sell for less than 30USD.

Last time I checked you already had to pay 40€ for a 5x86-100. There's a 50/50 chance that these run well at 120 MHz, however. From those I had, I kept the ones that run at 120 MHz and sold the rest. 😁

stamasd means collectors forum. eBay is another world. But as said, collectors don't care if a pin is missing or the cpu doesn't work - at least most of them.

kixs wrote:

stamasd means collectors forum. eBay is another world. But as said, collectors don't care if a pin is missing or the cpu doesn't work - at least most of them.

Correct. One sold just a few days ago for $30 on the forums at cpu-world. And believe it or not, collectors do care. A missing pin means a massive drop in prices people will pay.

Missing pin equals potentially unfixable dead CPU. And as a junk it's not worth much.

A missing pin can be soldered back usually, but most people don't bother to or have no skills to. I have intercepted a box of Tualatin-S CPUs once upon a time which was heading to a scrap refinery. Most CPUs missed a pin or two and those were important ones. Had to spend some time fixing.

kixs wrote:

stamasd means collectors forum. eBay is another world. But as said, collectors don't care if a pin is missing or the cpu doesn't work - at least most of them.

I definitely care if a CPU doesn't work, I even prefer no missing pins - though I may be okay with an unimportant missing pin (like one of a hundred GND lines) if the chip is rare and is fine otherwise.

CPU collecting is what led me deeper into retro computing. I wanted to test as many of my chips as possible - plus I have fond memories of the DOS demoscene and games.

I never said that no one cares. But I bought many times from different sellers and only a few times the cpus were in a good shape. Bent pins are standard. As no one has tested the cpus, you're buying at your own risk. The price is lower for a reason. If it works fine, if not, you can always resell it for the same price.

kixs wrote:

The price is lower for a reason. If it works fine, if not, you can always resell it for the same price.

The artificial word "mathom" pops into my mind 😐

I hope these mathoms won't get sold as "untested" again. But I fear they do.

Edit. As for the main topic, I've never seen a Cx5x86-133 in the wild and I don't have any. My only Cx5x86 is a -100 which is known to work because I tested it myself.

alvaro84 wrote:

The artificial word "mathom" pops into my mind :neutral: […]
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kixs wrote:

The price is lower for a reason. If it works fine, if not, you can always resell it for the same price.

The artificial word "mathom" pops into my mind 😐

I hope these mathoms won't get sold as "untested" again. But I fear they do.

Edit. As for the main topic, I've never seen a Cx5x86-133 in the wild and I don't have any. My only Cx5x86 is a -100 which is known to work because I tested it myself.

I meant resale it again on collectors site.