Upgrade opportunist needs 100MHz FSB Pentium III processor
January 25, 2011 9:45 AM   Subscribe

Best processor I can put in a very old but stable PC, and what can I expect from it? Slot 1 / Socket 370 era, max 100MHz FSB, Intel 440BX. Thief in the night / ninja style upgrade opportunity with stability and minimal risk a must.

The computer is a Celeron 433 with 640MB RAM on a 100MHz FSB motherboard (ABit BE6) running XP SP3. Early Matrox AGP graphics card (can't remember what now).

I tend to have only about two hours a year, due to geography, of physical access to this machine. Remote access over broadband with TeamViewer is subsequently easy.

Recently a couple of Web 2.0 type of things have proven too much for it: Google Docs and BBC iPlayer. Other than that, it works very well due to keeping the Windows install clean and due to the fact that the user doesn't do much apart from e-mail, solitaire games and web surfing. The slowdowns feel CPU bottlenecked. (Machine is connected to good ADSL.)

When I next get access to the machine I'd like to be packing the best processor I can put in it. I don't know much about the cooling specs in the case so I don't want to overclock or run anything that gets subtanstially hotter than a Celeron 433.

My reading is that the ABit BE6 is 100MHz FSB and Slot 1. I know that the Celeron 433 is a Socket 370 in a Slot 1 Slotket adapter.

The BE6 manual says PIII 550 MHz as the maximum, but I assume that's just what was on the market at the time of publication.

With 100MHz FSB in my pocket, my reading is I can go as far as a Coppermine 1100 MHz E-model Pentium 3 -- in Socket 370 form factor, which I should be able to put in the existing Slotket.

Prices on these old processors, looking at eBay, are not too high at all although the faster CPUs seem rarer amongst current auctions.

If you were being conservative, what would be the processor you'd put in this machine?

Any other factors I haven't considered? BIOS upgrade perhaps?

I'm not expecting this to necessarily get iPlayer going on the machine, but I'm hopeful at least of a noticeable boost that would get Google Docs to be more responsive browser-side.

posted by galaksit to Computers & Internet (14 answers total) 1 user marked this as a favorite
Swapping in a 1100MHz P3 would almost certainly affect cooling, and may even affect power consumption.

Honestly, with a machine that old I'd just buy a cheapo barebones box (something like this at Newegg), boot it up with a clean windows 7 installation, and then copy over whatever you needed.

Computers (especially desktops) are so cheap these days it's not worth your time to upgrade something that old.
posted by Oktober at 10:02 AM on January 25, 2011 [1 favorite]

If you were being conservative, what would be the processor you'd put in this machine?

PIII 550 MHz. Anything faster would likely be underclocked by the motherboard/bios.

The Celeron from that era is kind of crap, but I can't imagine a CPU will get you very far. Memory may be better (although not sure what the max is on that board), as 640MB is next to nothing with modern browsers (my unused instance of Firefox I use for testing is currently eating 174MB, and the Chrome I'm using for real is way above 640 at this point.)

I have to say I'm on Oktober's side - you're best just picking up a barebones and swap the whole box.
posted by General Malaise at 10:22 AM on January 25, 2011

Response by poster: The barebones box is an option, but money isn't the issue -- the window of physical access is, without perturbing a system that is only barely understood by a non-computer-literate relative. This is why I consider the CPU upgrade an interesting conservative option.

As well as the limited time window, the machine is located across international and mains electricity boundaries which increases the difficulty of introducing a new machine. Without this, then there would be no question I would be building or sourcing second-hand parts for a better machine. It may be what I do, but the CPU upgrade is still interesting to me, hence the question. If I did introduce a new machine, for instance, I'd have import duties and PSU sourcing problems if I built it in advance and either shipped it or carried it on a plane. If I did it at the remote end I'd have to build it quickly and hope nothing went wrong because I mightn't have time to fix it for another whole year. It's more attractive in many ways but, like I say, much less conservative than just a CPU upgrade. I'd like to try that and maybe go for the new machine next time around.
posted by galaksit at 10:31 AM on January 25, 2011

A celeron to P3 upgrade to a similar or higher speed is going to make a noticeable difference. Celeron 433s had 128k cache, P3 550 had 512k cache. This was really a big difference at the time.

I'd say get a P3 550 on ebay for $5 or whatever and try it - it might really help. If it doesn't work, toss it and put the Celeron back. You could plug in any speed of P3 you have and see what you get - heck I have some here you could try. Do you have a friend with a pile of that old stuff?

Yeah yeah, a whole new computer would be nice, but that's not the question being asked is it?
posted by fritley at 10:34 AM on January 25, 2011

Response by poster: Max RAM would be 768MB according to the BE6 manual.

Thanks for the answers so far. BTW, to add to all that, the relative is resistant to me buying a new machine.
posted by galaksit at 10:36 AM on January 25, 2011

You should be able to go up to 1GHz on that socket, but I would be very wary in doing so. Once you get up to the early 1GHz P3's you run into a couple of bad performing chips. General Malaise is probably right in 550MHz P3 is going to be a top end.

The issue you will likely hit is in your power supply. Celeron 433's were released around 1999. That means your power supply is likely 11-12 years old. Time and heat take their toll on capacitors. I would instantly knock the PSU's wattage down 40% off of what it was rated just to avoid blowing capacitors. I would then calculate appropriately based on wattages.

I would try to see about bringing along a replacement PSU, additional memory and a replacement fan or two if you really want to keep that computer going for a whole lot longer.
posted by Mister Fabulous at 10:36 AM on January 25, 2011

Would replacing the machine with a laptop be an option? A modern laptop would be a lot faster, and most laptop power supply bricks will handle a change of power type with just a swap of a power cord. You could probably even re-use their existing monitor and keyboard, if they prefer using them to the laptop keyboard & display. And you know, lots of travelers carry laptops, and if you just happened to forget yours at the relative's home, well, these things happen...

Assuming the relative has a high-speed connection, I would use TeamViewer to take over their machine and ship all their data to the new machine ahead of time. Then when you get there, just do a final update of data, and swap the laptop in for the old machine.
posted by fings at 10:59 AM on January 25, 2011

What sort of mains electricity boundaries? Most power supplies will take a 50-60Hz, 120-240V power inputs without complaining.

An Atom-Based PC will also fit in your carry-on luggage.
posted by schmod at 11:09 AM on January 25, 2011

Boy, a CPU replacement sounds WAY riskier than simply replacing the machine with a dirt-cheap but still vastly more capable machine. What if you bend the pins, or whatever? I haven't installed a CPU in a while but I remember always breaking into cold sweat just before installing one, due to the delicacy of the process.
posted by The Lamplighter at 11:57 AM on January 25, 2011

Response by poster: U.S./U.K. power. I didn't realise that I could get a U.K. capable PSU so easily in the U.S.

A laptop was an idea I considered but was against for yet more reasons to do with the relative's attitude to me spending real money on it, but those points are very fair and it could be set up to use the existing, familiar keyboard and monitor while as you say, fings, very easy to power. I'll think about it some more. Your point about sucking all the data over via TeamViewer first is a good one -- I have done that in the past to fix corrupted mailboxes, etc. Even an old second hand laptop would be an option, and have USB 2.0, for instance.

Thanks for the comments on increased power needs and heat. I must admit I am constantly amazed that the PSU is still working as it's actually from 1997. The absolute worst case scenario would be to get a blazing fast (comparatively) CPU on there and for it to work but kill the machine over the coming days or, well, just any time I am not there to replace it, which is nearly all the time. I had feelings along these lines but your comments have made me see it as a more concrete risk.

I do agree with fritley, though, that the CPU upgrade could have a significant effect relative to what is now in the machine, and the PIII 550s are super easy to come by. It is still probably worth a try for less than the price of a six pack!

As far as the CPU goes, I'm assuming I will not break the Celeron and would be able to swap it back in if needed. That said it's obviously more than ten years since I built that machine and I'm not even sure how hard it was to install the CPU.
posted by galaksit at 12:04 PM on January 25, 2011

IIRC, the "Slot 1" connector is the same type of edge connector you see in a Super Nintendo game. It's dead easy to switch. I'd be more worried about insidious heat/power effects creeping up later, e.g., it boots fine the first time, but if your dad is copying a cd to the hard drive the CPU doesn't get enough power and the system hangs, etc.
posted by Oktober at 12:59 PM on January 25, 2011

Most important:
Your existing Slotket may not be able to handle Coppermine-core CPUs; the earliest Slotkets can't. Check the manual to be sure.

I wouldn't worry about the power supply. A Celeron 433 consumes about 25 W, and a Coppermine-core P3 1100 consumes about 35 W, thanks to its lower voltage. Not a big difference.

The 1100 MHz coppermine P3 is ~$40, while the 1100 MHz coppermine Celeron is ~$20. It has half of the L2 cache, but it's otherwise identical.

Yes, get the latest BIOS from Abit to get the best processor support. I used to have the dual-CPU Abit BP6, and people actually made modified BIOSes for that board to support new CPUs after Abit stopped caring. If the CPU you want isn't covered by the official BIOS, a modified BIOS may exist.

You may be able to use Tualatin core processors if your Slotket supports them (or you mod the slotket). That would let you use a 1400 MHz Celeron (100 MHz bus, $25 new according to Pricewatch.com) or a 1400 MHz Pentium 3 (133 MHz bus, see below).

133 MHz FSB
You can run the Abit BE6 at 133 MHz FSB; the biggest problem you'll face is the AGP video card, which would have to run at an AGP bus speed of 89 MHz. The Matrox card may or may not be able to handle it; anecdotal evidence suggests that it can. You may find setting the AGP mode to 2x (instead of 4x) to be helpful.

Of course, your RAM also needs to support 133 MHz. You get a significant boost from the higher system bus, and you may need the extra memory bandwidth to be able to support Flash video. According to Pricewatch.com, you can get 512 MB of PC133 memory for $8.84, so don't let that stop you.
posted by LightStruk at 1:33 PM on January 25, 2011

Minor mistake: the 1100 MHz Coppermine P3 consumes 40 W, not 35 W. Still not a big difference in heat or power, but you will want a modest CPU fan that can handle that.

The 1400 MHz Tualatin P3s and Celerons consume less, about 33 W, thanks again to their lower voltages.
posted by LightStruk at 1:38 PM on January 25, 2011

Response by poster: Thanks LightStruk. I'm a little cautious of going to 133MHz in the time frame I'll have, but it's good to have the power consumption info for the chips.
posted by galaksit at 7:12 AM on January 27, 2011

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