I was reading a paper about Multi-core (several processors in the same package) vs single packed processors and I rembered why I didn’t enjoyed very much IT papers.
They tried to proof a multi-core architecure perform better than its older brother. They assume that a second processor in other package perform 80% and one in the same 70%.
Let have a processor of 3Ghz and dual-core of 2.2GHz each, you know they are made with lower speed to reduce power and heat:
- If you have two processors in differents packages, they perform as a single machine of: 3000Hz * 1.8 = 5400Hz
- If you have dual-core package they perform : 2200Hz * 1.7 = 3740Hz, so if we add another package you get: 3740Hz * 1.8 = 6732Hz
Oh! Yeah! You get much better performance with dual-core systems, nifty/cool!!!!
Let assume each extra package you add you loose a 20% of performe respect the previous package:
- If you have 4 processor of 3GHz each you get : 3000Hz * 1.8 * 4 = 21600Hz
Sigh! Who is right??!!
That’s why I love papers from biology journals, they almost never leave their proofs uncompleted.