Building an Athlon XP PC

It all started on a Thursday afternoon. After lunch with my colleagues, I went over to the Macintosh area of the local computer store where they had a Power Macintosh G5. After admiring the construction and quietness of the machine, someone brought a CD containing a 35+ megabyte Photoshop 7 file. We were going to see how fast this G5 would open the file.

Unfortunately, the bad news is that it took over one minute to open the file. Not very impressive considering Apple's claims of top-notch performance. Granted that there was only 256 Mb in the G5, but I didn't expect the G5 to fare much worse than the dual G4s we use at work.

Let's Buy

The next day, I decided to build a Linux PC. I wanted to get back into having a Linux PC after a two-year hiatus. I also wanted to see if I can get the whole thing built for under $300. My last PC was a 233 MHz AMD K6, and my friends have been raving about the performance of the Athlon (K7) CPU.

The first step is to go to my large bin of computer junk. I had traded my last PC for a bunch of computer parts, a VCR, and a beach ball. I decided that I could use an old DVD-ROM, a Maxtor 30Gb hard drive, a PS/2 keyboard a USB mouse, and an old 15" monitor for diagnostic purposes only.

I went down to the local screwdriver shop and bought the following:

ASUS A7V8X-X motherboard with onboard USB/Ethernet and AGP 8x graphics
Athlon XP 2000+ CPU
GeForce3 MX400 32Mb video card
512 Mb PC2700 RAM (166x2 MHz)
Ugly PC Mini-ATX case

Why they call the case "mini" is hard to fathom for this Mac user. PC cases are all ugly beige/black boxes and look terrible compared to Macs (as I will show later). I considered a Shuttle/XPC, but I had a budget. Total cost for all the parts above came to $293 after taxes. While building the PC, my Mac was downloading copies of a Linux distribution. I was a Debian user and I wanted to use Debian 3.0, but I changed my mind after finding out it required 7 CDs (or 1 DVD). I simply did not want to download that much stuff even over a broadband connection. So, I ended up getting 2 CDs that comprise Gentoo Linux 1.4.

Let's Build

This picture shows the parts I bought. The two recycled components (DVD and Hard drives) join the others. The first thing is to examine the CPU. The Athlon CPU has four rubber pads that act as a cushion against the much larger heat sink. A heat spreader and 11 resistors is mated to the heat sink by a small pad of phase-change thermal paste.

Next, the motherboard and case are taken out of their boxes. I like this motherboard because it has no active cooling other than the CPU. I chose the VIA K400 chipset over the Nvidia nforce2 for this reason. In the picture, PCI/AGP slots are on the left, internal ports on the lower right, 3 RAM slots on the center right, and the CPU, North Bridge chip, and external ports on the upper right. That's Capacitor City up there. Apple's motherboards look better, but this one is very straightforward and functional.

First, I put the CPU, heatsink, and RAM on the motherboard before placing it in the case. This ensures that I don't accidentally crack the motherboard since the RAM takes quite a bit of pressure to seat. One also has to make sure that the heat sink and CPU are mated, and that requires inspecting the motherboard from the edges. The G5 is cooled by nine fans. This motherboard attaches to the case with 9 screws and standoffs.

Closeups of the external ports can be seen here and here. From left to right, we have:

PS/2 Keyboard/Mouse ports
Digital audio output (SPDIF)
Parallel port (who uses this anymore?)
Serial port
USB 2.0 ports (2)
10/100BT Ethernet + USB 2.0 ports (2)
Sound in/out (I'm not sure what that third port is)

The next thing to do is to connect the case cables to the motherboard. There are two groups of cables. The first group comes from the front panel and they consist of the on/off switch, various LEDs, and the front-mounted USB ports. The next set of cables come from the power supply and the internal IDE connectors. All the connections are shown in this picture. Only the ATX connector from the power supply is connected to the motherboard. The IDE connector is seen in the center of the picture and all other connectors are all on the left side, right below the internal speaker. I have also installed the GeForce3 AGP card to the left of the 3 RAM slots.

Here is another view of the mess, after installing the audio cable from the DVD to the motherboard. Note a power supply cord going from left to right - this is for the case fan that we will show later.

IDE cabling hiccup

If you look closely at the previous picture, you'll notice that the grey IDE cable is a mess. This is because PC component manufacturers can't tell the difference between their heads and their asses. IDE connectors are notched. Good design dictates that all notches should point in one direction to minimize twisting of the IDE ribbon cable.

PC components are not examples of good design.

This picture shows that the IDE cable twists getting to the DVD (slave) drive on the top, then twists again before getting to the hard (master) drive on the bottom. Of course, the cable to the motherboard starts from the bottom. Down->Up->Down, and one 180 degree twist. I placed the hard drive below the DVD drive. That's where 3.5" drives belong, not in the 5 1/4" bay. I could have placed the hard drive above the DVD drive, but I would then need a $6 adapter. [Also, who knows, I may get three or four optical/removable drives later. Heh heh.]

Throughout the entire assembly of this PC, I only needed one tool - a dual-ended screwdriver.

Let's Boot

Here are pictures of the completed system : from the front and the back (the side case fan can barely be seen on the right side).

Again, the G5 has nine fans. This PC only has three - one for the power supply, one for the CPU, and the case fan to make sure air is circulating inside the beige box.

I used CD 1 of Gentoo Linux to boot the system - note that I do not have a floppy, as this PC can boot from the DVD/CD drive. Installing Linux was very straightforward if you want to use the default kernel configurations. Later on, I will attempt to create a custom kernel that only uses hardware I have. I expect the custom kernel to improve performance by as much as 15% to 20%. We'll see. Instructions for installing Gentoo Linux can be found here.

I installed the minimum files to boot Gentoo Linux into a GUI/X11 environment. Thus, this picture shows the barebones X11 display using the twm window manager. Note the mini keyboard I'm using since my deskspace is limited. The Apple USB mouse also seems to be working fine, although I really can't use it for X11 since there is only one mouse button. It's off to Fry's to get a $3 PS/2 mouse. I'm getting close to hitting my $300 budget limit ($293 + $3).

After about 3 hours of putting together a custom kernel, my new Linux PC found it's place under my computer desk. I use the dual VGA/DVI input on my LCD monitor to swtich between the two machines. Later, I may try to use a USB switcher to get rid of the PS/2 keyboard and mouse.

I don't think my G4 Cube was too happy with the new neighbor. That PC is huge compared to my Cube. I'm sure the G5 will be just as big when I get one next year.

The Test

I installed Gimp on the PC and opened up a 30 megabyte Photoshop file I had gotten from work. Here is a table of the single test of opening the file:

System	File Open Time 30 Mb Photoshop 6 file
PowerMac G5 - 256 MB RAM	1 minute
Linux PC (Athlon XP 2000+) - 512 MB RAM	3 seconds

I know that the difference in RAM is not proportional, but something about the G5s performance at the store tells me that even with 1 Gb of RAM, it won't be able to beat my $300 computer. I love the Mac and have always used it as my primary computer, but there are times when a fast CPU, a faster operating system, and an even faster graphics application makes a difference. This is one of those times.

Alex Morando