Overclocking the AT bus: Good or Bad idea? \ VOGONS

Overclocking the AT bus: Good or Bad idea?

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First post, by DonFuego

Posted on 2009-10-03, 15:32

DonFuego Offline

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My i486 BIOS allows me to set the clock divider for the AT bus. I tried running the AT bus at ~11 Mhz amd it seems to work although its about 35% overclocking. Do you guys have any experience of how much stress this puts on the components, stability, performance gain etc? I notice the Linear Read speed on the IDE card is increasing accordingly. Except for that I can't notice much difference.

I'm building the Ultimate 1994 Demo Scene Machine. Specs so far:

* i486DX2/66 * 32 Mb FPM 2-1-1-1/0 WS RAM * Cirrus Logic 5428 VLB 1 Mb (suggestions?)
* Maxtor uMAX II 6 Gb HDD * 3Com 3C509B * SB Pro 16 * GUS Max 1 Mb

Reply 1 of 3, by Anonymous Coward

Posted on 2009-10-03, 17:23

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It depends on what kind of cards you have on the AT bus. In most cases, I would strongly advise against clocking the AT bus over default 8MHz. Soundcards and SCSI cards in particular are pretty picky.

"Will the highways on the internets become more few?" -Gee Dubya
V'Ger XT|Upgraded AT|Ultimate 386|Super VL/EISA 486|SMP VL/EISA Pentium

Reply 2 of 3, by DonFuego

Posted on 2009-10-03, 17:31

DonFuego Offline

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Yep. Seems the performance gain is negligible with a VLB/PCI system anyway.... In my case, speeding up the VLB bus should do more effect. But I prefer stability/compatibilty. I guess I could throw a DX4/100 in there instead...

I'm building the Ultimate 1994 Demo Scene Machine. Specs so far:

* i486DX2/66 * 32 Mb FPM 2-1-1-1/0 WS RAM * Cirrus Logic 5428 VLB 1 Mb (suggestions?)
* Maxtor uMAX II 6 Gb HDD * 3Com 3C509B * SB Pro 16 * GUS Max 1 Mb

Reply 3 of 3, by swaaye

Posted on 2009-10-03, 21:07

swaaye Offline

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I've usually found that about 10 MHz is okay. I used to run my 486 with the FSB at 40 and ISA at FSB/10. Speed boost? I doubt it. I've read that it can be useful for ISA NICs, but if you need NIC speed you need a new bus and need to get rid of that ancient NIC! 😀

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