Rules for Buying a Used Computer on Craigslist

I have been teaching myself how to build computers for the past 8 months now and I have been learning quite a bit. I read as much as I can about the theory and operation of computer hardware and then I get to actually go and build computers form spare and refurbished parts. I also check out Craigslist a lot for cheap desktops and it kills me at what I find for sale on Craigslist.

I need to remind myself that most people are not in touch with reality when they go to sell their computer that they paid $750 for over 10 years ago. Most people don't know that Pentium 4 computers are not worth $200 unless they have a new $150 video card in them. Computers and their parts have dropped significantly in the past 5 years and it is no longer necessary to buy a basic computer for $750 anymore. Here are some guidelines on prices that are worth paying for older computers.


Pentium 4 Computers:

• Do not buy anything lower than a Pentium 4, 2.4GHz computer. Actually that means do not buy any computer that has a lower Passmark.com CPU rating of 300. Even with a decent video card performance on sites like YouTube will be less than desirable.
• I would only pay $50 for a P4 tower only if I saw it running, it has a 40GB or larger hard drive, and it has at least 512mb of ram.
• If you happen to get come across a P4, 3.0GHz or higher you can pay a little more for those but nothing over $75 unless it comes with a graphics card of 128mb or higher.

Pentium Duo or Dual Cores:

• There are a few dual core Pentiums that Intel came out with. There are Pentium D's, Dual Core's and Core 2 Duo's.
• These are all pretty good processors but don't over pay only because they are dual cores. Always check current CPU prices and system prices on http://www.pricewatch.com. That is where I get all of my current prices on what to pay and what not to pay.
• Always check the performance of every CPU you plan on buying used or not at http://www.passmark.com.

AMD Athlon XP's:

• These are older processors but don't write them off quite yet. Athlon XP 1800+ and larger are still capable of getting on the internet when using a Linux operating system.
• I have an Athlon XP 1700+ & 1800+ running with Linux Mint just fine, not the fastest, but definitely capable on the internet.

AMD Athlon 64's:

• I like the AMD Athlon 64 processors. I have built a 3500 and two 3800 machines and these when combined with a good graphics card are capable of playing 3D games like Nexuiz and Assault Cube.

AMD Athlon 64 X2 Dual Core:

• I have one of these as well, a x2 3800 and it runs as fast as my $1,000 Dell. I built the X2 3800 for about $80 with an ok graphics card. I could use an upgrade there.

AMD Athlon II X3:

• This is a fast processor, faster than anything my internet connection can throw my way.
• I have the X3 450 that is rated at 2802, yes that is almost 4 times faster than the fastest P4.
• I built my X3 system with kick ass graphics card for $220.

In summary I would only go to Craigslist to buy a cheap machine that you plan on upgrading yourself. It is worth it to me to get a nice looking desktop and get a case, usable hard drive, and power supply for $40. Buy yourself a nice CPU motherboard combo and some memory and you could have a really nice desktop for $100.

Computer System Speed Comparison

Computer Speed Tests for the Average Person

This section is my attempt at showing the differences between processors and how their performance ranks.

Computer Speed Analysis:

CPU Descrip.	CPU Speed	CPU Cores	CPU FSB	CPU Cache	64 Bit	Mobo FSB	Sys RAM	Video	CPU Rank	Benchmark
AMD Athlon X3	3.2 GHz	3	2 GHz	1 mb	Yes	1 GHz	4 GB	ATI 5450	2715	4.09 sec.
AMD Athlon X2	2.4 GHz	2	1 GHz	1 mb	Yes	1 GHz	2 GB	ATI X600	1050	9.15 sec.
Intel Dual E2140	1.6 GHz	2	800 MHz	1 mb	Yes	1 GHz	1 GB	TBD	907	10.75 sec.
AMD Athlon64 3800	2.4 GHz	1	1 GHz	512 mb	Yes	1 GHz	2 GB	On Board	610	14.99 sec.
AMD Athlon64 3500	2.2 GHz	1	1 GHz	512 mb	Yes	1 GHz	2 GB	Nvidia 6600 GT	567	16.15 sec.
AMD Sempron 3100	1.8 GHz	1	256 MHz	256 KB	No	533 MHz	768 MB	ATI X300	450	19.20 sec.
Pentium 4	2.8 GHz	1	533 MHz	512 kb	Yes	533 MHz	768 MB	ATI X300	415	20.98 sec.
Celeron	2.6 GHz	1	400 MHz	256 kb	No	400 MHz	768 MB	On Board	295	20.98 sec.

Take a look at the above chart and see how your computer stacks up. All of the machines shown above will get on the internet and surf the web. If you need a budget gaming machine I would stick with machine with CPU ranks above 550. What does this mean for you? Do not overpay for older Pentium 4 machines and before you shell out your hard earned dough on a computer make sure you check your CPU's performance rating.

So What Does this List Mean?

In layman's terms I would never buy a used or refurbished computer slower than a Pentium 4 2.8GHz and even then I would not pay more than $40 -$50 for it and only if it came with a decent amount of memory and good hard drive. My most surprising budget build was the AMD Athlon 64 3500. It was fast enough of a machine to play Nexuiz, a 3D fast paced FPS for Linux. I am sure the 2GB of RAM and Nvidia 6600GT video card helped.

Data Sources: CPU rankings were obtained from www.passmark.com, an excellent source of CPU data. The benchmark numbers are actual measurements that I received from performing the CNC Blowfish test on the Linux Mint 11 operating system.

Laptop IDE Hard Drives

I enjoy building desktop PC's but I recently traded for some laptops to see what they were made of. Three of the laptops were antique relics from the 90's and only one of them actually turned on and posted. Through  lot of trades I have finally acquired enough laptop hard drives to trade for something else. Here are a few pictures of them.

Seven Laptop IDE Hard Drives

The Desktop Is Not Dead

I have heard a lot and read a lot of articles that say the desktop is dead. I am here to say that is a lie! I am sure many retailers and big buisness want you to think the desktop is dead but there are many good reason to have one still as your main computer. I myself still prefer the feel and use of a full size keyboard and large computer screen. I feel the laptop and smart phone are nice to have but to really enjoy computer work one must have a nice desktop. High powered desktops are not just for the gamer. They are really great for doing high end graphics and CAD design.

The desktop is the only system that you can heavily customize based on your application. You can build yourself anything from a low cost internet machine to a high end 3D gaming rig that will blow you away. You cannot do that with your laptop, smartphone, or tablet. I think that is how future corporations want things to be. The desktop will still enjoy everyday use in most companies, schools, and other institutions so I don't think we have anything to worry about. Stay tuned for more of my posts and updated pages that will show you how to build your own affordable computers.