Well, the datecode is inline with the earliest 5x86 chips, but the font on both of those chips looks non-original.

feipoa wrote on 2024-02-23, 21:08:

Well, the datecode is inline with the earliest 5x86 chips, but the font on both of those chips looks non-original.

Could it be a fake...?, then I'll try it when there's a Socket3 motherboard on the test bench to see what it shows.

DarthSun wrote on 2024-02-24, 09:12:

feipoa wrote on 2024-02-23, 21:08:

Well, the datecode is inline with the earliest 5x86 chips, but the font on both of those chips looks non-original.

Could it be a fake...?, then I'll try it when there's a Socket3 motherboard on the test bench to see what it shows.

I'm not sure what a test will show. Both my 80 MHz 5x86 chips tested fine at 100 MHz. I'm not sure what criteria Cyrix used for qualifications. The most likely situation is that your 80 MHz CPUs were intended for OEMs so they deliberately left the speed grade off. I've seen Cyrix chips sent to some upgrade companies without the speed markings.

Sorry if already asked:

Is there any advantage to either of these CPUs? They're both tagged '6x86MX PR300' and both run at the same voltage but the multipliers and FSB are different:

- One is gold-topped and runs at 3 x 75MHz.
- The other is grey, and 3.5 x 66MHz.

The gold one looks nicer 🤣 - but I went with the other one because I don't want to be suckered out of my extra 6MHz.

When I was testing Cyrix CPUs I found higher MHz was better than higher FSB.

mwdmeyer wrote on 2024-04-14, 00:37:

When I was testing Cyrix CPUs I found higher MHz was better than higher FSB.

Thank you for confirming. I probably should have checked first with real people, damned ChatGPT assured me that that the higher multi version is better.

Is the difference significant?

No not massive. I think Cyrix used higher FSB as they struggled to get MHZ up, so it helped a bit.

I have completed the 6x86MX PR300 build and I’m…slightly underwhelmed.

I wasn’t expecting Coppermine performance, but Duke3D at high settings in DOS is not as butter smooth as I expected. Last time I tried it was on a DX2-66, so I thought this system would eat the game alive, but it’s jerky at times.

Fade To Black is excellent, much better than the 486 could ever run it. Might finally complete it.

Now, late 90s and early 2000s games seem to be out of the question. Project IGI is unplayable. Is this expected?

I should say at this point that my SS7 board does not have an AGP port and the only reasonably price PCI card I could find at this point was an FX 5500, I’ve modded an older, more lightweight driver to work with it which actually adds 20% to the performance, but still, any of the late 90s 3D stuff just chugs.

So is this normal for my CPU? Or is something wrong here?

Also, just to throw this out there:

3DMark 2000 with Pentium III 500MHz and FX 5500: 2940 marks.

3DMark 2000, same GPU but with 6x86MX: 746 marks.

Oof this is embarrassing, just noticed the external cache is disabled by default. Let’s try again.

6x86MX PR300 will be similar to K6 200MHz, no where near a P3.

mwdmeyer wrote on 2024-04-19, 00:12:

6x86MX PR300 will be similar to K6 200MHz, no where near a P3.

Of course. But I didn’t expect the P3 to bench 4x higher, especially a 500MHz one.

SSE in the driver probably

Almost certainly, somebody warned that anything pre-coppermine would bottleneck the 5500.

I’m at a loss as to what GPU to seek out for the PR300 given the lack of AGP.

I did a similar build and used a PCI Voodoo 3 2000.
https://www.youtube.com/watch?v=RZINWXDovHg

Otherwise TNT2 M64 PCI, Geforce MX 4000 PCI are some other options.

Wow, this thread brings back some memories.

I used to love Cyrix processors, in fact, I'm using an IBM branded one in my current Win3.11/DOS6.22 build. 😀

It was so nice to have 3 trusted options when I was building systems back then, Intel, AMD, and Cyrix. For many of my personal builds, I almost always picked Cyrix. After they went the way of the Dodo, I leaned toward AMD, as I still do to this day.

Good times!

The 6x86L makes me very sad, fine if you are doing basic windows/office apps but many issues with games and even some apps! Had a PR200+ and "downgraded" back to a Pentium 133.

The MX is much better.

mwdmeyer wrote on 2024-04-19, 01:25:

I did a similar build and used a PCI Voodoo 3 2000.
https://www.youtube.com/watch?v=RZINWXDovHg

Otherwise TNT2 M64 PCI, Geforce MX 4000 PCI are some other options.

Cheers appreciate it. There is a PCI MX 4000 for sale locally for a not terrible price. I notice they’re early 2000s cards, are they not shackled the lack of SSE in 6x86?

The Geforce MX 4000 is basically a Geforce 2 MX.

I'm honestly not sure if it will be better than the FX or not in that machine. I don't know how big a difference SSE makes in the drivers.

It is always possible that it will not improve anything!

EDIT: Google says NV18 so Geforce 4 MX, but again very simlar to Geforce 2.

There are a few more alternatives, but I am not sure if they would bring you an advantage.
I want to mention them anyhow.

Geforce 6 series:
- Geforce 6200: EVGA made some in PCI (512-P1-N402-LR and 256-P1-N399-LX), might be troublesome with the newer drivers, though
- Jaton made a version with 2 x Geforce 6200 on one PCB (VIDEO-348PCI-Quad)

Geforce FX series:
- Geforce FX5700LE: (from Albatron, Apollo and Jaton), probably all only with 64 bit, so not really an upgrade if you already have an 128 bit card
- Geforce FX5600: (Inno3D made some) they are like overclocked FX5500, but rather rare to find
- Quadro FX 600: like a slightly overclocked FX5500, rather rare to find
- Geforce FX5500: as you have
- Geforce FX5200: (offered by a lot of companies) just mentioned for the sake of completeness
- Quadro NVS 280 PCI: like a FX5200 64-bit, needs DMS-59 cable, also just mentioned for completeness

Geforce4 series (Might look slower spec-wise, but maybe driver more suitable):
- Geforce4 MX 420, 440, 460: those should exist in PCI as well, but I have yet to find those
- Quadro4 NVS 100/200: like a Geforce4 MX 440SE, needs DMS-59 cable
- Quadro4 NVS 400: like 2 x Geforce4 MX 440SE on one PCB, needs DMS-59 cable (?)

ATI/AMD side:
- R9250 256 PCI
- FireMV 2200 PCI: similar to Radeon 9200
- FireMV 2400 PCI: similar to 2 x Radeon 9200 on one PCB

The plain Radeon PCI would be worth considering also, there's some cheap on fleabay for ppl in the US listed as "HP ATI 64MB PCI Radeon..." but the international shipping price is horrible.