Southern Islands: a big hope in AMD’s GPU
1. Long glass and leave skirt
It is maybe, if
all of us decide to jump after the vibration-increase herd sound of Tahiti
played according to the way to name the high-end Southern Islands GPU. This
Tahiti XT chip is the first GPU producing 28nm we have ever seen. It is the
Tahiti Pro silicon array reduced in the upcoming HD 7950.
2. Prove itself
Dissatisfied
with being the first 28nm graphics card in the market, AMD also chose to change
the HD 7970 into the first card PCIe 3.0. Basically, that brings higher
available bandwidth. However, in the real world, it is almost not recognized.
3. Unworking cards
It may be the
fastest simple graphics card nowadays, but it still does impressive things with
power management. That is especially right in the CrossFireX architecture, and
in desktop mode, it can turn off completely unused GPUs until necessary.
4. In general
Graphics Core
Next GPU is not only about visual image since one of the main reasons for
rearchitecture is to allow higher ability in multi-functional computing
segment. So, HD 7970 is much powerful.
Graphics
Core Next GPU
Graphics Core Next architecture is built
from Compute Units, similarly to Nvidia’s threading microprocessors that it
introduced with Fermi architecture.
Tahiti XT GPU in HD 7970 is built with 32
of these Compute Units, which are basically independent processors that can act
independently.
In each Compute Unit, there are 4 vector
units, and in each vector unit, there are 16 homogeneous shaders, series
processors, or Radeon Core – depending on the person to whom you are talking.
That means in full Tahiti XT, you will find 2,048 shaders, and compared to
1,536 shaders of HD 6970, this is a quite impressive number.
Thanks to the combination between 4-way
vector processing and this scalar architecture, AMD hopes to push Tahit-based
GPUs to the first row of the graphics card segment.
However, it is not the number of Compute
Unit that creates difference in pertformance - Radeon HD 7970s real core clock
is also higher than previous cards. With the 925MHz, it is faster than Radeon
HD 6970’s 880MHz.
Money’s value
Now, we talk about the performance of this
new graphics card silicon array. It is very fast. Ah, quite fast.
HD 7970 beats Nvidia GTX 580 about graphics
card performance, image point increase, polygon processing. In all game tests,
HD 7970 made Nvidia card be ranked as the second, especially when you consider
the heavily required Heaven 2.5 and Crysis 2 tests. With these two tests, you
will see an improvement of 30% compared to Nvidia GTX 580.
However, we are scripts in the best cases,
because performance advantage in other games is not very outstanding, just
improves frame speed from 13% to 20%.
When talking about the previous generation
– HD 6970 is provided power by the famous Cayman – everything appears to be
more impressive. HD 7970 as 65% improvement compared to the older card in the
Heaven 2.5 test. It is the fastest performance increase, but in the worst case,
it is also around 25% faster.
It is all before you waggle overclocking
magic wand. This chip can be overclocked. In fact, we encountered the limit of
AMD OverDrive software rather than that of hardware. We pushed the card to
1125MHz over core clock speed and 1575MHz over memory clock speed.
With these numbers, performance increase
compared to GTX 580 and HD 6970 is more remarkable, with HD 7970s beating the
last generation nearly 80%. When overclocked, it is also as nearly good as the
last generations of two GPU, GTX 590 and HD 6990. GTX 590 has the highest speed
of 33fps while HD 7970 is close to 32fps. HD 6990 stands behind it with 29fps.
However, it is not only about raw
performance data since AMD has had much effort with Radeon HD 7970s power
demand, especaIlly when running in free mode and with turned off screen.
ZeroCore Power technology means that when the screen is turned off and the
computer falls into long free mode – where computer still runs but nothing is
updated on its screen, so the screen falls into sleep mode – there is only a
simple chip on card that still runs.
That chip is present so as for the computer
to know that there is still a card in PCIe slot and there is no need to worry.
The remained part of graphics card is completely turned off, including fan.
