Help overclocking an AMD 5x86 133

Posted on 2020-11-18, 16:47

by

by squelch41

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hi, I am trying to overclock my 5x86 but keep failing! It runs fine at the stock 133MHz but if I move the bus speed up to 40MHz, it is unstable. It will POST and I can get to a dos prompt if I dont load the ESS cdrom driver (usually crashes if I do). Pretty sure it is an ADZ varient but there is a …

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Re: Help overclocking an AMD 5x86 133

Posted on 2020-11-18, 16:58

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by debs3759

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

It sounds to me like you lost the CPU lottery, as you appear to have tried everything else.

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Re: Help overclocking an AMD 5x86 133

Posted on 2020-11-18, 17:10

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by rmay635703

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Some motherboards/cards aren’t stable at 40mhz and need different settings or even in some cases different cache

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Re: Help overclocking an AMD 5x86 133

Posted on 2020-11-18, 19:56

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by schlomoe99

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

rmay635703 wrote on 2020-11-18, 17:10: Some motherboards/cards aren’t stable at 40mhz and need different settings or even in some cases different cache I agree here. Have you tried switching from Write-Back cache to Write-Through cache in the BIOS?

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Re: AMD DX4 100MHz build

Posted on 2020-11-18, 20:18

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by RetroSpector78

in Marvin \ System Specs

in Marvin \ System Specs

Intel486dx33 wrote on 2020-11-17, 14:40: If you posts your Speedsys and topbench results I can compare with my VLB 486dx4-100 build. SpeedSys 4.78 = 37.55 TopBench 3.8 = 192

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Re: AMD DX4 100MHz build

Posted on 2020-11-18, 20:23

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by RetroSpector78

in Marvin \ System Specs

in Marvin \ System Specs

Oh, you have the write through version of the Am486DX4. Can you post a picture from the bottom side of your ST3660A please? Which SRAM and DRAM timing do you have in your BIOS? 20201118212026.png 20201118212031.png Haven't done much tuning yet. Enabling the CPU->PCI mem post write buffer seems to …

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Re: Help overclocking an AMD 5x86 133

Posted on 2020-11-18, 20:25

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by The Serpent Rider

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

(though looking online, it seems that pretty much all of them are? ADZ =/= better overclocking. ADZ can officially operate stable at higher temperatures and that's about it. If you can, increase voltage to 4V and it most likely will boot.

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Re: AMD DX4 100MHz build

Posted on 2020-11-18, 21:13

by

by Disruptor

in Marvin \ System Specs

in Marvin \ System Specs

Your ST3660A is a model without a chip from Creative Labs. Oh you have lots of wrong settings. Your ISA bus is overclocked to 11 MHz. ISA BUS clock should be 1/4 PCLK. All timings below should be set to minimum. You may enable DRAM Slow Refresh. You may enable CPU Burst Writes. PCI IRQ Activated By: …

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Re: Help overclocking an AMD 5x86 133

Posted on 2020-11-18, 21:57

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by PC-Engineer

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Three guesses from my side: 1. If you have a VLB IDE controller replace it with an ISA type. The VLB is not specified for two cards @40MHz. It is difficult to find a combination of cards, board and CPU which is running stable at 40MHz. 2. replace the Power supply or at least the capacitors at the …

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Re: Help overclocking an AMD 5x86 133

Posted on 2020-11-18, 22:08

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by squelch41

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Some motherboards/cards aren’t stable at 40mhz and need different settings or even in some cases different cache I agree here. Have you tried switching from Write-Back cache to Write-Through cache in the BIOS? Hmm, no I haven't. Though disabling the L2 cache all together made no improvement. Will …

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Re: Help overclocking an AMD 5x86 133

Posted on 2020-11-18, 23:53

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by adalbert

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The Serpent Rider wrote on 2020-11-18, 20:25: ADZ =/= better overclocking. ADZ can officially operate stable at higher temperatures and that's about it. If you can, increase voltage to 4V and it most likely will boot. Yeah, I once bought ADZ for overclocking, just to find out that my ADW worked …

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Re: AMD DX4 100MHz build

Posted on 2020-11-19, 00:37

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by maxtherabbit

in Marvin \ System Specs

in Marvin \ System Specs

Disruptor wrote on 2020-11-18, 21:13: Your ISA bus is overclocked to 11 MHz. ISA BUS clock should be 1/4 PCLK. Bullshit, if it is working at 11MHz he should leave it be I always overclock my ISA when possible, 11 is tame - it's when you get up over 12 that things stop working

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Re: AMD DX4 100MHz build

Posted on 2020-11-19, 07:13

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by RetroSpector78

in Marvin \ System Specs

in Marvin \ System Specs

Your ST3660A is a model without a chip from Creative Labs. Anything special about that combo ? Oh you have lots of wrong settings. Your ISA bus is overclocked to 11 MHz. ISA BUS clock should be 1/4 PCLK. All timings below should be set to minimum. You may enable DRAM Slow Refresh. You may enable …

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Re: AMD DX4 100MHz build

Posted on 2020-11-19, 12:50

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by Intel486dx33

in Marvin \ System Specs

in Marvin \ System Specs

Can you posts your benchmark results ?

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Re: Help overclocking an AMD 5x86 133

Posted on 2020-11-19, 20:27

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by amadeus777999

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Try another chip - you may have a dud.

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Re: AMD DX4 100MHz build

Posted on 2020-11-19, 20:52

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by RetroSpector78

in Marvin \ System Specs

in Marvin \ System Specs

Intel486dx33 wrote on 2020-11-19, 12:50: Can you posts your benchmark results ? Edited the original post with some numbers.

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Re: AMD DX4 100MHz build

Posted on 2020-11-19, 21:37

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by Intel486dx33

in Marvin \ System Specs

in Marvin \ System Specs

Those CPU benchmark scores seem low. I have seen higher scores using the Lucky star LS-486 motherboard. Even my VLB motherboard with Intel overdrive 486dx4-100 CPU scored a little higher. Are you using EDO ram ?

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Re: AMD DX4 100MHz build

Posted on 2020-11-20, 18:44

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by Disruptor

in Marvin \ System Specs

in Marvin \ System Specs

RetroSpector78 wrote on 2020-11-19, 07:13: ... With minimum you mean the lowest CCLK's values ( = should translate to higher throughput / performance) ? Cause all the ones you see are the lowest values. That is sad.

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Re: AMD DX4 100MHz build

Posted on 2020-11-20, 19:13

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by Disruptor

in Marvin \ System Specs

in Marvin \ System Specs

The Intel 486 dx 4 - 100 with 16 kb write back cache is really good.

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Re: AMD DX4 100MHz build

Posted on 2020-11-20, 19:16

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by Disruptor

in Marvin \ System Specs

in Marvin \ System Specs

Disruptor wrote on 2020-11-20, 19:13: The Intel 486 dx 4 - 100 with 16 kb write back cache is really good. Can you post a speedsys chart of your 486 / 100 overdrive? (I'm interested in your cache chart.)

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