AlessandroB wrote:

I take this opportunity for something I have in my head for a while. What is the benefit of using 5x86P75 instead of DX2? Aside from a benchmark talk, it's not as fast as a pentium so you earn some frames in heavy games like Doom but you lose the fact of having the legendary DX2 in your computer. Although slower it is still interesting to try the games in the cpu which was the standard (pre pentium). Not know if i explain. There is neither a 486 nor a Pentium. At the time it could be interesting to upgrade a 486, but now ?? If you need the speed of the pentium better get a pentium

The 5x86 gives you an extra bit of overhead while still working on a Socket-3 board. There's also the Pentium Overdrive 83MHz which was actually a Pentium slotted to Socket-3 if you want Intel's ultimate offering for the platform. At any rate, I believe the popularity is due to the fact that most people building 486 rigs are (speaking for myself at least) going back to the time when they wanted that bit of kit but could not afford it or justify the expense at the time. (Let's be honest here, a lot of this hobby is deferred wish fulfillment.)

Quake was the hard breakpoint between the 486 and what came after, and if you want to run Quake era games well you're better off going a bit beyond the original Pentium. I'm planning a K6 as my next true build but that's not going to be for a while yet.

j^aws wrote:

I can look into PMMX benches next time I'm running through testing the board. IIRC, the slowest PMMX on this board was around Speedsys 1.0 - 1.5 compared to Speedsys 0.45 for the K6-III+. Whilst the slowest Speedsys for a K6-III+ I've benched is 0.1 on another board. For reference, Speedsys 0.5 is around 4.77 MHz Intel 8080 territory on an IBM XT.

The PMMX is still very flexible - it just lacks the lower and higher end scores. It can also produce a smooth profile due to extra parameters available via Setmul.

Don't worry about any further detail on my account. You've given me a general sense of how the PMMX scales and that's what I was mainly interested in. I believe I remember K6-x processors being more sensitive to RAM performance. Was that confirmed by your work tweaking the memory controller for lower speeds?

j^aws wrote:

BTW, those K8 scores behave similarly to Pentium 4 with cache disabled, possibly faster in the DX4 region.

Indeed, although if this were other than an OEM machine, I would be able to manually reclock the LDT bus for more flexibility. Locked multipliers spoil some of the fun for Netburst CPUs.

gdjacobs wrote:

j^aws wrote:

I can look into PMMX benches next time I'm running through testing the board. IIRC, the slowest PMMX on this board was around Speedsys 1.0 - 1.5 compared to Speedsys 0.45 for the K6-III+. Whilst the slowest Speedsys for a K6-III+ I've benched is 0.1 on another board. For reference, Speedsys 0.5 is around 4.77 MHz Intel 8080 territory on an IBM XT.

The PMMX is still very flexible - it just lacks the lower and higher end scores. It can also produce a smooth profile due to extra parameters available via Setmul.

Don't worry about any further detail on my account. You've given me a general sense of how the PMMX scales and that's what I was mainly interested in. I believe I remember K6-x processors being more sensitive to RAM performance. Was that confirmed by your work tweaking the memory controller for lower speeds?

I don't recall making direct comparisons with RAM tweakings between a PMMX and K6. I lumped everything under BIOS options as one parameter, which included memory timings and chipset options, e.g. bus waitstates. These BIOS settings become very sensitive at ultra low speeds here, where a change can mean a difference between an XT and Turbo XT score. I'm sure both a K6 and PMMX would behave slightly differently with just memory tweaking.

gdjacobs wrote:

j^aws wrote:

BTW, those K8 scores behave similarly to Pentium 4 with cache disabled, possibly faster in the DX4 region.

Indeed, although if this were other than an OEM machine, I would be able to manually reclock the LDT bus for more flexibility. Locked multipliers spoil some of the fun for Netburst CPUs.

Not common, but you can get unlocked Netburst CPUs. Not as flexible as unlocked Core2s, as they can clock down to 600 MHz, and clock over 3GHz+. Combined with ISA DMA aware chipset (i865), they make a great compliment to K6/ VIA C3 builds.

sirnephilim wrote:

AlessandroB wrote:

I take this opportunity for something I have in my head for a while. What is the benefit of using 5x86P75 instead of DX2? Aside from a benchmark talk, it's not as fast as a pentium so you earn some frames in heavy games like Doom but you lose the fact of having the legendary DX2 in your computer. Although slower it is still interesting to try the games in the cpu which was the standard (pre pentium). Not know if i explain. There is neither a 486 nor a Pentium. At the time it could be interesting to upgrade a 486, but now ?? If you need the speed of the pentium better get a pentium

The 5x86 gives you an extra bit of overhead while still working on a Socket-3 board. There's also the Pentium Overdrive 83MHz which was actually a Pentium slotted to Socket-3 if you want Intel's ultimate offering for the platform. At any rate, I believe the popularity is due to the fact that most people building 486 rigs are (speaking for myself at least) going back to the time when they wanted that bit of kit but could not afford it or justify the expense at the time. (Let's be honest here, a lot of this hobby is deferred wish fulfillment.)

Quake was the hard breakpoint between the 486 and what came after, and if you want to run Quake era games well you're better off going a bit beyond the original Pentium. I'm planning a K6 as my next true build but that's not going to be for a while yet.

You talk only about performance but not about what DX266 was... having the CPU that open the PC-Gaming era. And in my opinion Play Doom at the original DX2 fps rate is a part of the game.

Warlord wrote on 2019-08-31, 23:44:

I'm working on such a system, that nobody here has done. […]
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I'm working on such a system, that nobody here has done.

915 Mobile Chipset with a Pentium M Single Core
Aureal Vortex MX 300 for 98se + Audigy 2 ZS for XP
Quadro FX1300 This is a NV38 AGP FX gpu on a PC Express Bridge. This should give me max compatibility with DX 5 to DX 9 So i still get support for things like table fog.

SInce Pentium Ms are unlocked I should be able to use plenty of slow down tricks sinces its a mobile chip Is my plan. and I should be fast enough to run XP smoothly even browse the WEB with it.

I have another trick up my sleeve with it, I have a brodcom crstal HD that I am going to put in it so it can even do HD Video watching. So basically max coverage single system. DOS to 2005 XP.

Because 915 chipset is probably 99% suported in 98se and 100% supported in XP It should be good

All of this is theory ofcourse thing is sitting on my bench right nnow.

Any news about your project? I found a cheap Quadro FX1300 and that can be very interesting to me...