Buying Old PCs

I install quite a number of internet gateway machines for one of my clients. While eventually he will probably move to using an ASUS EeePC [1] or something similar, the current plan is to keep using desktop PCs (unfortunately server-class machines make too much noise).

P4 machines use an unreasonable amount of power and don’t seem worth getting second-hand. P3 machines are the most power efficient machines that have been commodity PCs (with keyboard and monitor), see my computer power use document for an example [2].

So what I would like is to get a dozen name-brand P3 systems at a reasonable price. Currently the only companies I can find selling such machines are charging ridiculous prices (such as $300) with the aim of reaming corporations who want to complete a set of old machines rather than upgrading them all. Most online auctions etc are selling P4 and Celeron 2GHz as the minimum hardware. The Celeron machines are better than P4 (at around 50W) but not as good as P3 (at less than 40W).

If you read this post and are in Melbourne, Australia and have a name-brand P3 desktop system that you want to sell then let me know. If you have any suggestions of how to buy such machines then I’m interested in advice.

14 comments to Buying Old PCs

  • Jkinz

    Hi, I have solved your problem in a slightly different way. I use thin clients. They use tiny amounts of electricty, have enough CPU horspoer to do the job and, (some models), enough room for an extra NIC card. By re-writing the flash memory with a small linux kernel (equipped with iptables) I can produce a solid, stable, low power gateway system
    for a low price.

    These guys have some of thelowest cost units I have seen:

    (This is not a reccomendation as i have not yet purchased from them. )

  • While old desktops are doing a good job, I’d recommend an upgrade in any case. I’ve seen a design of a solar powered computer on Tom’s Hardware some time ago. [1] Of course it’s not the solar power that caught my attention, as the concept is from outside my climate zone. What took me was that using stock *desktop* parts they created a dual core 64-bit system (with a regular HDD and a DVD) that idles at an astounding 38 Watts + 23 Watts for the monitor. [2]

    I use my Mobile P3 1,13G in Thinkpad T23 and I couldn’t be more happy. The system idles at under 20 Watts and is a great machine unless I need more power. I might have seen your table on power consumption before, but I didn’t notice the huge advantage of P3 over early AMD K7. Then suddenly Intel went insane with the P4 and non-SpeedStep D-series. My cousin got the “finest” of this breed, the infamous D960 with TDP 130 W(!). It has SpeedStep, but he refuses to use it, because it supposedly affects responsiveness.



  • What about the intel d201gly? Unless you need a bunch of pci slots, you can’t beat an incredibly reliable setup in a mini-its case. Around $75 USD, but you’d need a case and a power supply. I use ones from mini-box, $50 for the case and $20 for the PS. I forgot to mention that in my experience the power supply is a huge consumer of power. I prefer using a DC-DC power supply,they are way more efficient.

    A properly setup little valley can use only 20-25 watts and its a powerful little machine. Doesn’t make much heat or noise either.

    I notice the link about the eeepc as a router – check out the pc engines ALIX. Its awesome – 1, 2, or 3 10/100 nics, all under 5 watts. If you are running linux or openbsd there is a driver for the aes security block, as well as a hardware rng. For routers, that’s my favorite, coupled with pfsense. Soekris makes similar hardware but I find their prices a little out of my range.

  • etbe

    Jkinz: I’m after machines to use as low-end servers and routers. Having 2 Ethernet ports and the ability to add more is mandatory. Also I want them to be stand-alone and be usable in a typical PC manner (IE keyboard and screen).

  • Actually, not all P4’s are that bad. Previously, I used a Dell OptiPlex GX240 machine as my home server (1.5GHz P4). With p4-clockmod, cpufreq, and a tickless kernel, the machine used ~38W idle, up to ~80W (kernel build). Since the machine was idle most of the day it was usually using less than 40W. I suppose things get worse very fast >1.5GHz.

    Fortunately in The Netherlands there is a company (NowThatsIT) that sells such machines for less than 100 Euro.

  • @Daniel:
    Desktop P4 1.5Ghz is the slowest of them all, so the lower power consumption is understandable. Your processor has a TDP of 55 or 58 Watts (depending on voltage) which is considerably more then the fastest P3 1.4GHz with a TDP of 32 Watts. [2] The huge gap is hardly justifiable. Because of the numbers I seriosly doubt the total demand under full load of 80 Watts.

    The P4 “Willamette” (180 nm) you have is actually technologically inferior in almost every way to the final P3 “Tualatin” (130 nm) line. The 130 nm P4 models were far better, as for the same TDP as your model they reach 2,2GHz.


  • Check into – they often have old, cleaned up hardware for cheap. I’ve bought a lot of stuff from them and have been quite satisfied. Unfortunately they don’t seem to have any P3s right now.

  • etbe

    Marcin: Thanks for the Toms Hardware link, that’s interesting stuff. While solar power might not work too well where you are, wind power might be an option.
    Albert: The d201gly looks like a nice board (link above). But if I used it then I would have to get back into the PC assembling business which is something I don’t desire.

    Daniel: I have not yet tested machines with a tickless kernel. My document on power use is idling on an older kernel, so I’ll have to do a bunch of new tests when the tickless kernel becomes common. I expect that the new test results will still show P3 machines taking less than half the power of P4 machines.

    Albert: Thanks for the reference for US readers. For me it seems unlikely that it would be possible to do business with them given the delay and expense of international shipping.

  • @marcin: I used a reliable appliance energy meter. But it’s probably not representative for the average P4 machine ;).

  • I didn’t say it’s impossible. You may got lucky to have an energy efficient mainboard. Chipset plays a huge role in power consumption, that’s why Core 2 on P35 still uses more power then Athlon X2 on AMD 790, even though it has lower TDP.

    One way or the other, P4 is as ad-hoc market-filler released by Intel because of AMD’s momentary advantage in desktop processors performance. Intel took one step forward and two (if not five) steps back. The much later Core processors were based on a Mobile P3 architecture, rather then P4 and smash its predecessor on every field.

  • Hi Russell – I hear you, building one computer can be fun, building two interesting, any more and its time for an assembly line! :-)

  • etbe

    Marcin: The P4 was simply bad by design. The Intel marketting people were pushing clock-speed so they produced CPUs that ran at a higher clock rate without regard to performance. The P3 core apparently does 1.5* as many instructions per clock cycle as a P4 core on average, so scaling up the P3 core with hyper-threading (as is the rumoured origin of the Core series) was obviously the right way to go.

    Albert: Yes, it is an assembly-line process. Red Hat’s “Kickstart” thing is good for this, it’s a pity that we don’t have something similar for Debian.

  • (an auction site that sells government seconds) has a bunch of PIII desktops at the moment for sale. Here’s a lot of 11 which seems to be IBM, HP, Compaq, Dell and erm, Ipex…

    I guess if you kept an eye out there on the site there’d be more.

  • etbe

    daveg: Thanks for the reference, I just won a couple of P3 systems on dola. I spent $18 on the auction and shipping is $52. $70 for two Compaq machines seems like a good deal. Of course I have to wait and see if they work…