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when an end-user is executing 3 or 4 processes simultaneously to a pair of opportunis-
tic virtual machines on a single desktop, the individual completion time of such
processes is approximately duplicated.
A
B
10%
10%
8%
8%
6%
6%
4%
4%
2%
2%
0%
0%
1
2
1
2
User processes
User processes
Fig. 2.
Measurements obtained on AMD Athlon X2 5000+ processors. A was obtained by using
VBox and B was obtained by using VMware.
These results show that intrusiveness directly depends on specific implementation
of technologies aimed to deliver performance and energy-efficiency on modern pro-
cessors. The results can be attributed to the fact that each subsequent generation of
processor architectures incorporates improvements on the performance and optimiza-
tions on thermal-controls. In particular, it is worthwhile to note that processors Intel
Core i7-4770 and Core i7-2600 incorporate Turbo Boost technology in version 2.0
whereas processor Intel Core i5-660 incorporates such technology in version 1.0.
Thirdly, Figure 4 shows the intrusiveness percentage measured over a desktop
based on the Intel Core i7-4770 architecture. In such tests, Turbo Boost technology
was deactivated from the BIOS. As a result, intrusiveness percentage decreased 4.3%
on average; however, similarly to the results previously presented, it can be increased
up to 60% in the worst case.
In such scenario centered on Intel processors and based on the limited data col-
lected, we hypothesize that variations not attributed to Turbo Boost technology may
be produced by other dynamic performance and energy-efficient technologies able to
modify power consumption, temperature, and CPU rate, among others features of the
processor. They include but may not be limited to: SpeedStep, Hyper-Threading, and
Thermal Monitoring technologies. They were designed to optimize energy consump-
tion and increase performance under particular circumstances. Therefore, reducing
intrusiveness through deactivation of such technologies is actually a counterproduc-
tive arrangement. In such case, the overall performance would be reduced dramatical-
ly thus meaning permanent intrusiveness to end-users.
