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486DX PC running really slow. Thoughts?

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Reply 40 of 46, by rmay635703

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darry wrote on 2021-01-19, 20:27:
alvaro84 wrote on 2021-01-19, 18:14:
rmay635703 wrote on 2021-01-19, 16:31:

Sadly Intel insisted on this holy terror

CF39475D-45CD-4568-B19A-39CB9AA5DF3E.png

What a beautiful and pointless chip, definitely missing from my collection...

This one is more pointless, IMHO, ecpecially considering the 1991 release date .

https://en.wikichip.org/wiki/intel/80486/486sx-16

At least you could overclock every 16mhz sx to 50mhz

The dx2-40 did serve one purpose
They used less power in laptops which is where they eventually ended up when dx2-66s were mainstream
but one wonders why they needed the clock multiplier to do that?

Reply 41 of 46, by darry

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rmay635703 wrote on 2021-01-19, 20:59:
At least you could overclock every 16mhz sx to 50mhz […]
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darry wrote on 2021-01-19, 20:27:
alvaro84 wrote on 2021-01-19, 18:14:

What a beautiful and pointless chip, definitely missing from my collection...

This one is more pointless, IMHO, ecpecially considering the 1991 release date .

https://en.wikichip.org/wiki/intel/80486/486sx-16

At least you could overclock every 16mhz sx to 50mhz

The dx2-40 did serve one purpose
They used less power in laptops which is where they eventually ended up when dx2-66s were mainstream
but one wonders why they needed the clock multiplier to do that?

I imagine that at least some 486DX2-40 chips coukd be overclocked to 50 or even 66 MHz .

My thought about the 486SX-16 part was why would Intel bother releasing a part that was probably barely competitive with a 386DX-25 ? Maybe they were trying to push people to buy a shiny new 486DX-16, even if crappy, by promising low cost up front and convenient but not that cheap overdrive upgradability down the line ?

Reply 42 of 46, by rmay635703

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darry wrote on 2021-01-19, 21:32:
I imagine that at least some 486DX2-40 chips coukd be overclocked to 50 or even 66 MHz . […]
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rmay635703 wrote on 2021-01-19, 20:59:
At least you could overclock every 16mhz sx to 50mhz […]
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darry wrote on 2021-01-19, 20:27:

This one is more pointless, IMHO, ecpecially considering the 1991 release date .

https://en.wikichip.org/wiki/intel/80486/486sx-16

At least you could overclock every 16mhz sx to 50mhz

The dx2-40 did serve one purpose
They used less power in laptops which is where they eventually ended up when dx2-66s were mainstream
but one wonders why they needed the clock multiplier to do that?

I imagine that at least some 486DX2-40 chips coukd be overclocked to 50 or even 66 MHz .

My thought about the 486SX-16 part was why would Intel bother releasing a part that was probably barely competitive with a 386DX-25 ?

convenient but not that cheap overdrive upgradability down the line ?

Why offer a dx2-40 that is barely competitive with a dx33?
(In reality if the dx33 has VLB, it likely wasn’t)

Intel had its arm twisted by Dell to make a 16mhz sx to slot in the significant gimped value 486 segment, because reasons

Dells plans obviously didn’t work out (very few 16’s exist)
and Intel made cash by relabeling other sx chips as 16mhz just for Dell who is the only reseller I know of that carried them.

Yes it was a way to save cash and have an upgradable unit later on but from what I remember the SX16 in question wasn’t priced all that well and didn’t make sense even then
Considering $2000 16mhz, 1992, 2mb Ram, onboard 256k vga made for a slug with limited ISA upgradability

Reply 43 of 46, by nathanieltolbert

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Any ideas on if any of those three points on the CD-ROM drive relate to the strength of the laser? If not I understand, but super high speed DVD/CD drive in there right now is driving me nuts with how loud it is when running. On a more modern pc it's not much of an issue due to the fact that you don't use it as often, but in a 486 Multimedia PC, it's constant. I would like to get back to the BTC 16X, I just need to improve the laser as it doesn't read all of my legit CDs.

Reply 44 of 46, by alvaro84

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appiah4 wrote on 2021-01-19, 12:54:
alvaro84 wrote on 2021-01-19, 12:35:

But I should give a "486DX-60" a try. 66...? I'm not sure. Because VLB and all.

That's why he said PCI motherboards.

Well, it took this long but finally I got a PCI/5x86@180 system working. It's the M912's PCI counterpart, the M919 but it performed even a tad worse than the M912. No problem, the 160 setting feels so right, it just works with the fastest cache/memory settings and when I can force the PCI bus NOT to fall back to half speed it performs okay-ish in that respect too - still very far from Shuttle HOT-433 (same UM8881/88 chipset) for some unknown reason, much closer to something SiS496 based.

And, unlike 180, many (though not every) 5x86 can do it at stock voltage.

Shame on us, doomed from the start
May God have mercy on our dirty little hearts

Reply 45 of 46, by weedeewee

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nathanieltolbert wrote on 2021-01-29, 15:35:

Any ideas on if any of those three points on the CD-ROM drive relate to the strength of the laser? If not I understand, but super high speed DVD/CD drive in there right now is driving me nuts with how loud it is when running. On a more modern pc it's not much of an issue due to the fact that you don't use it as often, but in a 486 Multimedia PC, it's constant. I would like to get back to the BTC 16X, I just need to improve the laser as it doesn't read all of my legit CDs.

On the first photo you posted is the only potentiometer you could adjust. from the photo it seems to be at the halfway position. No Idea if it's the laser intensity pot, so give it a try, a little bit to the left, or a little bit to the right.
Best to only test it the casing closed. Enjoy & Good Luck.

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Reply 46 of 46, by Am386DX-40

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rmay635703 wrote on 2021-01-18, 23:49:

58B9B76C-4F42-4774-BE1C-204B6928ABF2.pngEven the original 486-20 had a DX in the long string on the bottom of the chip (from what I can remember)

Cant find a pic of a survivor from 1989

Here