Article View: comp.os.msdos.misc
Article #3623Re: Run 33MHz CPU at 40/50MHz?
From: Harald Milz
Date: Thu, 07 Jan 1993 17:35
Date: Thu, 07 Jan 1993 17:35
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In article <1993Jan6.162636.9927@ac.dal.ca>, francis@ac.dal.ca writes: |> I have a 486DX/33MHz system, and I have been told by the manufacturer that |> the motherboard is upgradeable to 50MHz by plugging in a new crystal and CPU. |> |> Question: Is it possible to plug in (say) a 40MHz or even a 50MHz crystal |> into the board *without* replacing the old (33MHz) CPU? |> If so, is there a performance improvement or will the 486DX 33MHz chip just |> burn itself out, ie, has it been internally hardwired for the specified clock ^^^^^^^^^^^^^^^ ^^^^^^^^^ burn out: veeeery probably. hardwired: not directly. The chip's power consumption does not allow for higher frequencies. In priciple, the shorter the switching times of the CMOS transistors, the less the power consumption will be (which occurs mainly during the hi-to-lo and vv. transition). Switching times are a random result in the manufacturing process, so that all chips from 33 to 50 MHz are born from the same fab. They are selected for frequencies thereafter. Intel shot the bird: When having problems with their 486DX at higher frequencies, thus producing many chips that wouldn't work even at 25 MHz, they un-bonded the co-pro and named the result 486SX-20. -- | iX | Harald Milz | email: hm@ix.de | | Multiuser | Editor | phone +49 511 547 47 66 | | Multitasking | Helstorfer Str. 7 | fax +49 511 547 47 33 | | Magazine | D-3000 Hannover 61 |
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Newsgroups: comp.os.msdos.misc,comp.os.msdos.programmer Path: arc1-ca.pugleaf.net!sparky!uunet!mcsun!Germany.EU.net!rz.uni-hildesheim.de!ix.de!hm From: hm@opus40.ix.de (Harald Milz) Subject: Re: Run 33MHz CPU at 40/50MHz? Message-ID: <1993Jan7.173530.27394@opus40.ix.de> Sender: hm@opus40.ix.de (Harald Milz) Organization: iX-Redaktion References: <1993Jan6.162636.9927@ac.dal.ca> Date: Thu, 7 Jan 1993 17:35:30 GMT Lines: 27