To make the economics tangible, take the following baseline hardware parameters. ⁴ 2 GHz CPU with 2GB RAM (cabinet and networking) $2,000 200 GB disk with 100 accesses/ second and 50 MB/s transfer $200 1 Gbps Ethernet port-pair $200 1 Mbps WAN link $100/month From this we conclude that $1 equates to = 1$ ≈ 1 GB sent over the WAN ≈ 10 TOPS (tera CPU operations) ≈ 8 Hours of CPU time ≈ 1 GB disk space ≈ 10 M database accesses ≈ 10 TB of disk bandwidth ≈ 10 TB of LAN bandwidth The ideal mobile task is stateless (no database or database access), has a tiny network input and output, and has huge computational demand. For example, a cryptographic search problem: given the encrypted text, the clear text, and a key search range. This kind of problem has a few kilobytes input and output, is stateless, and can compute for days. Computing zeros of the zeta function is a good example. ⁵ Monte Carlo simulation for portfolio risk analysis is another good example. Of course, SETI@Home is a good example: it computes for 12 hours on half a megabyte of input. Using parameters above, SETI@Home performed a multibillion-dollar computation for $1 million—a very good deal! SETI@Home harvested more than a million CPU years worth more than $1 billion. It sent out 1 billion jobs of a half-megabyte each. This pet-abyte of network bandwidth cost about $1 million. The SETI@Home peers donated $1 billion of “free” CPU time and also donated 10¹² watt-hours, which is about $100M of electricity. The key property of SETI@Home is that the ComputeCost:NetworkCost ratio is 10,000: 1. It is very CPU intensive. Most Web and data-processing applications are network or state intensive and are not economically viable as mobile applications. An FTP server, an HTML Web server, a mail server, and an OLTP (online transaction processing) server represent a spectrum of services with increasing database state and data access. A 100-MB FTP task costs 10 cents, and is 99 percent network cost. An HTML Web access costs 10 microdollars and is 88 percent network cost. A Hotmail transaction costs 10 microdollars and is more CPU intensive so that networking and CPU are approximately balanced. None of these applications fits the CPU-intensive stateless requirement. Data loading and data scanning are CPU intensive; but they are also data intensive, and therefore not economically viable as mobile applications. Some applications related to database systems are quite CPU intensive—for example, data loading takes about 1,000 instructions per byte. The “vision” component of the Sloan Digital Sky Survey that detects stars and galaxies and builds the astronomy catalogs from the pixels is about 10,000 instructions per byte. So, they are break-even candidates: 10,000 instructions per byte is the break-even point according to the economic model in table 1 ( 10 TOPS of computing and 1 GB of networking both cost a dollar). It seems the computation should be at least 30,000 instructions per byte (a 3: 1 cost benefit ratio) before the outsourcing model becomes really attractive. The break-even point is 10,000 instructions per byte of