Great value and performance, if you buy the
right version
The HD 7970 3GB is the old man here, first
seen in our last GPU Labs. Since then Nvidia has released the GTX 680 2GB, and
at first, it seemed to surpass the HD 7970 3GB’s performance for a similar
price of $639.
AMD
Radeon HD 7970 3GB GHz Edition
However, AMD’s improved Catalyst drivers,
its decision to legitimize the overclocked GHz Edition version of the card,
plus rigorous price cuts, have reversed the card’s fortunes. The Tahiti XT GPU
at its heart is now far more competitive.
That GPU is based around AMD’s Southern
Islands architecture and comprises 32 compute units, which in turn are made up
of four SIMD (single instruction, multiple data) engines of 16 stream
processors. The result is a total of 2,048 stream processors. Unlike Nvidia’s
kepler architecture, which performs tessellation at the SM level, the Southern
Islands architecture uses a dual front-end design that contains the GPU’s pair
of tessellators as part of its two geometry engines. Texture units are split
with four to a compute unit, giving you a total of 128, while the card’s six
64-bit memory controllers give you a 384-bit memory interface.
Stock HD 7970 3GBs ship with a set core
clock speed of 925MHz and a memory frequency of 1,375MHz, but the GHz Edition
increases this dramatically. The memory increases to 1.5GHz (6GHz effective),
for a huge 288GB/sec peak memory bandwidth, and the GPU gains AMD’s own clock
boosting tech. a base clock of 1GHz can increase up to 1,050MHz as long as the
card remains under its 230W TD. However, there’s a great deal of confusion
between older stocks of the 7970 3GB and the GHz Edition – be sure to look for
cards rated to 1,050MHz.
the
HD 7970 3GB GHz Edition is power-hungry, with our system guzzling 314W compared
to 273W with the GTX 680 2GB installed.
In Unigine Heaven, the HD 7970 3GB GHz
Edition scored 1,863, just two points off the GTX 680 2GB. At 1,920 x 1,080,
the GeForce has the edge, though, producing a minimum frame rate that’s 4fps
faster in BF3. However, at resolutions above 1,920 x 1,080, the GHz Edition
takes control, with results faster or equal to the GTX 680 2GB in almost every
test. In The Witcher 2, at 2,560 x 1,600 its minimum frame rate of 44fps is 12
per cent higher than the GTX 680 2GB’s 39fps. However, the HD 7970 3GB GHz
Edition is power-hungry, with our system guzzling 314W compared to 273W with
the GTX 680 2GB installed.
Conclusion
Costing at least $47.9 cheaper than the GTX
680 2GB, the HD 7970 3GB GHz Edition is now a major contender, offering superb
performance at higher resolutions for a very reasonable price. Just be sure to
grab a GHz Edition with its higher clocks speeds, rather than the slower
standard model.
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Details
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Price
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$559
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Manufacturer:
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www.amd.com
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Comeback:
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Cheaper than a GTX 680 2GB and faster at
high resolutions
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Rollback:
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High power consumption; variety of
versions is confusing
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Scores
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1920 speed:
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17/20
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2560 speed:
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18/20
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5760 speed:
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4/5
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Value:
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34/55
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