View Full Version : Computer question

08-10-2000, 08:40 AM
My computer, Packard Bell, 680 Orlando, has a motherboard which runs at 3.3 volts. It has a Pentium processor running at 120MHz. Others have installed 233 MMX processors in this board and it works with the appropriate jumper settings and BIOS upgrades. The 233MMX is designed to run at 2.8 volts, however, and this board has no voltage regulator.

How much extra heat can I expect to have to dissapate via a heat sink and fan because of the increased voltage? How much of a safety factor is built into a processor which will allow it to operate outside of it's normal design voltage without frying?

I know this isn't a computer chat line, but I'm impressed by the knowledge the of engineers who post here.

08-10-2000, 10:02 AM
First, I hate Packard Bell and would recommend replacing it. That's just my opinion, though, and if you're determined to keep this computer, it shouldn't cause too much trouble. I've found that the MMX processors can handle the extra voltage, although I wouldn't recommend it. I would shop around for a fairly large heat sink w/ a built on fan. Don't use the one that came with the original processor. I don't think it would be enough. Other than that, just try it out. If the processor starts to overheat, you'll know it pretty quick. The PC will start flaking out pretty badly. If you turn the computer off right then, you can probably avoid permanant damage to the chip. As a fan of overclocking, I've done this a few times. Good luck anyway.

08-10-2000, 10:07 AM
I'm not an engineer, I'm just a commercial real estate agent but I have been inside more than my fair share of PC's. With that caveat aside here is the free advice.

While it is fun (sometimes too much fun!) to upgrade older machines you can find complete and semi-complete 233 desktops for $50-$70. (see Ebay and auction sites) Given that 233 chips by themselves are typically $ 15-$30 it might make more sense overall to go the entire machine route for the few extra dollars involved and still have a backup system.

Given the relatively small voltage differential a 233 CPU could conceiveably run without a VR on your box but why put your data integrity (if it's important) at risk by stressing the CPU. Were taking tens of dollars difference after all.

If it's really just a goof to see if it works try it, however, even a $ 15 to $ 20 big, fat high quality heat sink-fan combo is not going to entirely solve the over voltage problem. You are still pumping more voltage through the CPU than it was specified to handle and beyond heat issues this simply isn't a good idea for a stable system.

08-10-2000, 01:52 PM
Go with the advice above, it'll be cheaper ( and easier on the nerves )to simply by a better machine.
Even the most BASIC new machine would work out cheaper than any serious upgrade.

HP sux re: upgrading.

08-11-2000, 10:23 PM

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