Those are pretty ridiculous coolers for any Pentium MMX. Were they trying to air-condition the server room at the same time?

The sticker on the southbridge is typically Soyo, if dual MMX, this has to be i430HX chipset, so this is almost certainly a Soyo 5TH0/H2/H5:
http://www.uncreativelabs.de/th99/m/S-T/34070.htm

Agreed that those Gorbs deserve a P3 that actually needs cooling. For P55C, they would work fine as passive heatsinks, just disconnect the fan.

Edit:
As for other stuff - it's an HX chipset. so max RAM 512MB. How much is cacheable depends on the tag RAMs, with one it can only cache 64MB, with two it can cache all 512MB. That pic shows two tags, so 512MB is cacheable.

Apart from that, max official CPU is P233MMX, but the chipset can easily handle 75MHz FSB and frequently also manages 83MHz. You can't do dual CPU on K6 or MII CPUs, but you can overclock those P200MMX beauties if you can figure out how to... it might be interesting to see what setting JP10 and JP11 both to open does. Depending on the PLL, it might do 55MHz (crap), 68MHz (not really interesting) or 75MHz (now we're talking).

yes, this is SMP Soyo 5TH10 (intel 430HX)

Wow, cool. I have seen a bunch of dual slot 1 boards, but dual socket 7 is a lot more rare.

I am like 99.999% sure there were no MMX dual cpu boards. The best chips those could be are the non-mmx 200.

luckybob wrote:

I am like 99.999% sure there were no MMX dual cpu boards. The best chips those could be are the non-mmx 200.

Afraid it's that 0.001%

P55C was SMP-capable, and any i430HX chipset will (with suitable VRM and BIOS support) do SMP with them. Years back I ran two myself on a P65UP5/C-P55T2D (weird backplane motherboard with two different CPU boards, either 2x So7 with i430HX chipset or 2x So8 with i440FX chipset). Apart from this Soyo board Asus also had a more 'normal' dual P55C-board, the P55T2P4D. They even still have it on their support site, with official support for P200MMX and P233MMX: https://www.asus.com/supportonly/PE-P55T2P4D/HelpDesk_CPU/

I own the p65up5, and its big brother p65up8. ^.^ Although I do need to get the p55t2d card.

I'm kinda still in the camp of MMX not being SMP.

I'm willing to bet the farm, the board might accept a single MMX chip and run fine, but its burned into my brain, SMP wont work with MMX. I'd LOVE to be proven incorrect though! The only dual socket 7 board I own (TYAN S1562D) specifically states, no smp with mmx. Doens't even allow jumper settings for 233mhz either. (A tyan board)

luckybob wrote:

I own the p65up5, and its big brother p65up8. ^.^ Although I do need to get the p55t2d card.

I'm kinda still in the camp of MMX not being SMP.

I'm willing to bet the farm, the board might accept a single MMX chip and run fine, but its burned into my brain, SMP wont work with MMX. I'd LOVE to be proven incorrect though! The only dual socket 7 board I own (TYAN S1562D) specifically states, no smp with mmx. Doens't even allow jumper settings for 233mhz either. (A tyan board)

Not sure about the Tyan S1562D, but the S1563D certainly seems to be able to do it: https://youtu.be/Ruwltdtff-g

Edit:
Another Vogon did it on the S1562D too - Tyan S1562 Dual Pentium MMX succes

luckybob wrote:

I'm kinda still in the camp of MMX not being SMP.

I was pretty sure about that too, until reading this thread - and the links in this thread .. I'd like to own a P55 SMP system 😎

n0m4d wrote:

Hi. Can somebody tell me something about this MB?

I can tell you that it looks AMAZING and that I WANT IT.

luckybob wrote:

I own the p65up5, and its big brother p65up8. ^.^ Although I do need to get the p55t2d card.

I'm kinda still in the camp of MMX not being SMP.

I'm willing to bet the farm, the board might accept a single MMX chip and run fine, but its burned into my brain, SMP wont work with MMX. I'd LOVE to be proven incorrect though! The only dual socket 7 board I own (TYAN S1562D) specifically states, no smp with mmx. Doens't even allow jumper settings for 233mhz either. (A tyan board)

Overdrive MMX processors are definitely not SMP capable, but it seems regular MMX processors are - eg https://datasheet.octopart.com/PENTIUM-MMX-23 … eet-7279168.pdf

Have also a dual MMX with smp
Re: Dual Socket 5/7 Boards

luckybob wrote on 2019-08-18, 00:02:

I own the p65up5, and its big brother p65up8. ^.^ Although I do need to get the p55t2d card.

I'm kinda still in the camp of MMX not being SMP.

I'm willing to bet the farm, the board might accept a single MMX chip and run fine, but its burned into my brain, SMP wont work with MMX. I'd LOVE to be proven incorrect though! The only dual socket 7 board I own (TYAN S1562D) specifically states, no smp with mmx. Doens't even allow jumper settings for 233mhz either. (A tyan board)

I think you are thinking of tillamook which indeed can not smp any of the times that I have tried.

JidaiGeki wrote on 2019-08-21, 09:18:

luckybob wrote:

I own the p65up5, and its big brother p65up8. ^.^ Although I do need to get the p55t2d card.

I'm kinda still in the camp of MMX not being SMP.

I'm willing to bet the farm, the board might accept a single MMX chip and run fine, but its burned into my brain, SMP wont work with MMX. I'd LOVE to be proven incorrect though! The only dual socket 7 board I own (TYAN S1562D) specifically states, no smp with mmx. Doens't even allow jumper settings for 233mhz either. (A tyan board)

Overdrive MMX processors are definitely not SMP capable, but it seems regular MMX processors are - eg https://datasheet.octopart.com/PENTIUM-MMX-23 … eet-7279168.pdf

Why on earth would they not implement smp on the overdrives? 🤔 seems like a no brainer for upgrading socket 5 smp systems.

The Gigabyte GA-586DX is another dual socket 7 mainboard with Pentium MMX support.

Socket 5 / 7 Pentium Overdrives. Higher Multipliers? SMP? Let’s find out..

I’m about to do some investigation into smp on overdrive mmx. I think it’s gonna work actually. Looking over the datasheet the pins for smp seem to be active.

Smp even quad and octa was supported on the pentium II overdrive. (Though only dual officially) So I think it’s gonna work, but I gotta figure out if I can do it between a overdrive and a non overdrive. I think I’ll only run it long enough to see it detect. Then power down till I get two overdrives.

I´m quite sure MMX ODs are capable of SMP since Intel must have been aware of dual Socket 7 systems. This means double business when upgraded.
In the case of the Tillamook the focus was on the mobile market (with single CPU designs).
Btw - this Soyo Dual Socket 7 HX-board has two TAG-RAM chips and was probably released about the same year as the SY-5TF (with just one). So Soyo did know how to do it right.

majestyk wrote on 2022-06-04, 08:41:

I´m quite sure MMX ODs are capable of SMP since Intel must have been aware of dual Socket 7 systems. This means double business when upgraded.
In the case of the Tillamook the focus was on the mobile market (with single CPU designs).
Btw - this Soyo Dual Socket 7 HX-board has two TAG-RAM chips and was probably released about the same year as the SY-5TF (with just one). So Soyo did know how to do it right.

(MMX OD) http://db.zmitac.aei.polsl.pl/Electronics_Fir … ts/29060701.pdf
Page 16 - "D/P# O The Pentium OverDrive processor with MMX technology does not support dual processing."

vs

(MMX) (https://datasheet.octopart.com/PENTIUM-MMX-23 … eet-7279168.pdf)
Page 17 - "D/P# O The dual/primary processor indication. The Primary processor drives this pin low when it is driving the bus, otherwise it drives this pin high. D/P# is always driven. D/P# can be sampled for the current cycle with ADS# (like a status pin). This pin is defined only on the Primary processor. Dual processing is supported in a system only if both processors are operating at identical core and bus frequencies. Within these restrictions, two processors of different steppings may operate together in a system."

However it would be fun to know if there is a workaround!

Well, I can confirm at least one of those is most likely incorrect.

Re: A-symmetrical MPS on pentium 1 multi processor PC

I appear to have gotten two pentiums to run at different speeds. Even though cpuz refused to admit it, super pi highly suggested it was a success.

I could take this one step further using solder on processor shim tweakers, and cutting the pins. Set one at 1.5x, one at 3x and test again. Should give a better confirmation.

As for mps on overdrive.. we’ll see. Though if the datasheet says no, then maybe not…

Sphere478 wrote on 2022-06-04, 09:24:

Well, I can confirm at least one of those is most likely incorrect.

Not necessarily. There's a difference between "is not supported" and "cannot work".

i440BX at 133MHz isn't supported, 1GB of SDRAM on i440LX and for that matter enabling 256kB of L2 on a K6-2+ 😉 isn't supported yet they work.

Challenge is figuring out which of the two is the case here.