Cloud Delivery and Hosting Models - Deploying and Managing a Cloud Infrastructure - page 163

Listing all the benefits of off-premises hosting would be redundant because we would
simply be reiterating the benefits of cloud computing in general, but here is a short, self-
explanatory list:

Global accessibility

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Scalability

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Built-in business continuity

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Consistency

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Miscellaneous Factors to Consider When Choosing
between On- or Off-Premises Hosting

Many people choosing between on- and off-premises hosting are focusing on raw face
values and losing view of the bigger picture. They tend to look at the simple arithmetic
involved of simply adding up-front costs and subscription fees, failing to see that there are
actually other factors that may affect the performance and cost throughout their system's
lifetime. Most of the factors that should also be considered (described in the following sec-
tions) will be pro off premises.

Power/Electricity Costs
This one should be obvious, but it is surprisingly always left out when considering costs
associated with running an on-premises system. It is probably because the power bill does
not come broken down into insightful tidbits, showing which items are consuming the most
power. The bill just encompasses all the consumption of the office or building, so it would
not be apparent to the decision makers how to factor the power consumption cost into the
total cost of ownership (TCO).
Most computer components—and by extension, computer systems—now consume less
power than their equivalents about a decade ago. But that does not mean their electrical
consumption has to be ignored. Unlike a laptop or a PC, a solid server contains a mixture of
multi-socketed processors, multiple sticks of memory, multiple sets of drives (often arranged
in a RAID configuration), multiple NICs and other components required for such a class of
computer, cooling systems, and two or more power supplies to power everything. That does
not sound like an economical machine; in fact, it sounds like a power-guzzling beast. If we are
to make a comparison to vehicles, consider a laptop as a Prius and that server as a Hummer.
A server contains a lot of components that a regular PC does not need because the key definers
of a server are power, uptime, and availability. That means this thing has to run 24/7.

Bandwidth Costs and Limitations
Off-premises or public cloud solutions can bring a lot of benefits, but just like the power
required to run servers in-house, bandwidth issues may come around to haunt you if you
do not do enough research.