Some of the hardware in the UWM Beowulf system

Jason Harrington and Damien Cho showing off the insides of one of the 300 XL machines. These machines are perfect for our purposes: they have a 1.28 or 2.11 GByte SCSI disk, 8 SIMM slots that take standard (ie, cheap!) memory, a 4 x CD-ROM and a floppy disk built in. Most importantly though, they have a 300 MHz DEC Alpha 21164 CPU that is an excellent floating-point engine. The CPU lives on a plug-in board which is the large horizontal board about halfway up the open part of the system box. The gray plastic bit about halfway up on the right is a diverter that directs air from one of the system fans (bottom right) over the CPU heat sink (shiny rectangular object sticking up in the middle of the CPU board, just below and to the right of the bright red bar). These machines were designed and sold as the "Windows NT dream machine" but apparently DEC was not very successful selling to that market and decided to discontinue the product in early 1998. We bought up the last of the production machines for a very good price.

We purchased industrial quantities of SIMMS (about 7 gigabytes of 32 meg SIMMS) since this was the most cost-effective way to add physical memory to the systems. The 300XL can use "industry-standard" devices. The picture.sho.jpgws three trays that hold 50 SIMMS each.

This is a close-up of one of our 100BaseT fast ethernet cards. These cards (DEC DE500) come in three flavors, the DE500-XA, DE500-AA, and DE500-BA (plus a fiber-only card). Of these, we were not able to get the -BA models, which are the most recent ones, to work properly with either the tulip or de4x5 drivers. The -XA cards would not auto-negotiate properly. The -AA cards were the best choice.

The inside of a machine.

Another shot of the guts...

Some of the machines were DOA. Fortunately they were purchased with a three year on-site warranty. This is our DEC Service Engineer, Mr. Walter Spann, getting ready to swap a CPU board!