Digital 60

Horace: Manchester's most powerful PC

Horace isn’t a supercomputer. But he’s pretty special.

Horace is the University of Manchester’s single most powerful computer. Run and maintained by the Manchester Research Computing Division, this monster of information technology is housed in a temperature-controlled room in a building on the edge of the Science Park.

As Manchester's most powerful computer in 2008, Horace is the current holder of Baby's crown. So how do the two machines compare?

Check the specs - calculators at the ready!

NB. Due to the charges in computer architecture and the way they’re built, it is not possible to do a direct comparison and it’s important to note that figures are not like for like. However, they give a rough idea of the vast explosion of computing power in the last 60 years:

Baby

• One processor
• Dimensions: 5.2m long x 2.2m high and weighed one tonne
• Memory: 1024 bits
• It could only store a total of 32 numbers and instructions eg. an 80Gb iPod has 64 million times more storage than Baby
• Computing Speed: 1.2 milliseconds per instruction = 833 calculations per second
• It had less computing power than the average calculator today

Horace

• 192 processors
• Dimensions: 3m long x 2m high and weighs ¼ tonne
• Memory: has 24 nodes each with 16Gb RAM ie 3,072,000,000,000
• in other words, has 3 trillion times more storage memory than Baby
• Computing Speed: (now measured in floating point operations or FLOPS)
• Horace operates at 1.2 TeraFLOPS (10¹²) = 1,200,000,000,000 single calculations per second
• So Horace is 1,440,576,230 – or 1.4 billion - times faster!

Calculation

The first program to run successfully on Baby, on 21 June 1948, was to determine the highest factor of a number ie. the highest number that will divide exactly into the first number.

The original number used was quite small, but within a few days the team had built up to trying the program on 2¹ (2 multiplied by itself 18 times). The program tested each number down from 262,143 (2¹-1) to 131,072 (2¹), which is the initial number's highest factor. This meant that around 120,000 numbers were tested, which took about 2.1 million instructions. The correct answer was obtained in a 52 minute run.

If the maths are right, Horace would perform the same task in 0.00000222857 of a second!