# 0.6 Results and discussion  (Page 2/5)

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Similarily, [link] compares SFFT to FFTW 3.3 running in patient mode, and [link] compares SFFT to SPIRAL. There are fewer columns in the heatmaps of [link] because SPIRAL only computes single-threaded FFTs for sizes ${2}^{1}$ through to ${2}^{13}$ .

## Fftw 3.3 in estimate mode

[link] shows that SFFT is faster than FFTW 3.3 running in estimate mode in almost all cases over a range of Intel x86 machines that implement SSE. The horizontal streaks of yellow-red that can be seen in some heatmaps are outliers and likely caused by transient system processes that were running while SFFT was being benchmarked. Similar streaks appear at the same locations in Figures [link] and [link] .

## Fftw 3.3 in patient mode

[link] shows that SFFT is faster than FFTW 3.3 running in patient mode in the majority of cases over a range of Intel x86 machines that implement SSE. SFFT was generally slightly slower than fftw3-patient on older machines such as the Pentium 4's and the 1GHz Pentium M, while on the newer machines such as the Sandy Bridge based Core i7-2600 and the Nehalem based Core i5-660, SFFT was clearly faster than FFTW (see [link] ). This could be explained by the fact that FFTW performs extensive instruction level optimizations, such as scheduling, and that the older processors have smaller instruction and trace caches.

## Spiral

The last row of [link] shows that SFFT is generally slower than SPIRAL when both libraries are compiled with clang 1.1. However, with more recent releases of clang, which do much more code optimization, the situation is reversed, as shown in [link] . In some cases SPIRAL compiled with clang 3.0 is slower than SPIRAL compiled with clang 1.1, while SFFT is generally faster when compiled with clang 3.0. This demonstrates that the speed of automatically tuned SPIRAL code is specific to certain compilers.

SPIRAL's double-precision performance is slightly better than SFFT when compiled with icc or gcc, while SFFT's single-precision code is faster than SPIRAL on recent machines, and of similar speed on older machines.

## Avx

Of the machines that were used for benchmarks, only two supported AVX: the Macbook Air 4,2 with an Intel Core i5-2557M, and a Linux machine with an Intel Core i7-2600. [link] shows that SFFT is clearly faster than FFTW up until about 1024 points, while performance between the two is similar for larger transforms.

Results for Intel IPP are also plotted in [link] , but only for the Core i7-2600. IPP did not detect the existence of AVX on the Core i5-2557M, and instead used SSE, as plotted in [link] . Apple vDSP does not support AVX, and so SSE vDSP results for the Macbook Air 4,2's Core i5-2557M are also plotted in [link] .

## Arm neon

SFFT and FFTW 3.3.1 were compiled with Apple clang 3.0 and benchmarked on an Apple iPod touch 4G and an Apple iPad 2, which contain the Apple A4 and A5 SoCs respectively. The A4 implements the ARM Cortex-A8, while the A5 implements the ARM Cortex-A9, both of which support ARM NEON.

anyone know any internet site where one can find nanotechnology papers?
research.net
kanaga
Introduction about quantum dots in nanotechnology
what does nano mean?
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
it is a goid question and i want to know the answer as well
Maciej
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
for screen printed electrodes ?
SUYASH
What is lattice structure?
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
what's the easiest and fastest way to the synthesize AgNP?
China
Cied
types of nano material
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
how did you get the value of 2000N.What calculations are needed to arrive at it
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