AMD’s New Flagship GPU Shakes
Things Up
In last month’s review of the Nvidia
GeForce GTX 580, we advised our readers
to hold off. We’re generally not nostalgic
types, but with the launch of AMD’s
Radeon HD 6970, the contentious battle
for graphics supremacy really takes us back.
There’s nothing quite like two high-end
GPUs launching in close proximity. The
fanboys are frothing, prices are falling, and
we can’t help but get a little teary.
AMD’s Cayman XT owes its 2.7 TFLOPs
of raw compute performance to an 880MHz
core clock, and its 5.5Gbps memory bandwidth
to a 1,375MHz memory clock
and 2GB of GDDR5 running on a 256-
bit bus. Architecturally, the Radeon HD
6970 offers significantly enhanced geometry
performance, even compared to the
6800 series GPUs. Cayman features dual
graphics engines, which double the vertex
and geometry assemblers and deliver faster
geometry setup. Each SIMD features 64
ALUs; there are 24 SIMDs, which gives the
GPU a total of 1,536 ALUs.
AMD also revamped its shader hardware
by moving from VLIW5 (Very Long
Instruction Word; originally introduced
in the R600) to a VLIW4 design, which
utilizes four identical shader units compared
to VLIW5’s four identical units plus one
special function unit. Although the move
from VLIW5 to VLIW4 sounds like a
step backward, the special function unit
was extremely underutilized in previous
architectures, and by cramming more SPUs
into the reclaimed die area, AMD is able to
realize a 10% performance improvement
per mm2. AMD has also tweaked the render
back-ends to deliver faster 16-bit integer and
32-bit floating point operations. There are
96 texture units and 32 ROPs. Other new
features include AMD’s eighth-generation
tessellator and support for a new AA setting
called Enhanced Quality Anti-Aliasing.
The 6970 also features AMD’s fifthgeneration
vapor chamber technology, which
keeps the GPU cool and relatively quiet. As
a nod to enthusiasts, AMD added a dual
BIOS toggle switch, which lets you install a
performance-tweaked BIOS without fear of
bricking the card. If the BIOS fails, just flip
the switch, reflash the BIOS, and try again.
The switch won’t keep you from melting
your card, so practice caution when
installing and running these tweaks.
We like to think of TDP as the
upper limit for component power
consumption, but in reality, GPUs
tended to exceed that limit when
running rare workloads, such as
synthetic benchmarks like FurMark.
With AMD’s new PowerTune technology,
when the predetermined power
limit is reached, the GPU dynamically
lowers the core clock. This is important,
considering the 6970 matches the GTX
580 in load temps and noise output.
AMD claims that typical gaming and
idle power for the 6970 is 190W and
20W, respectively, well below its 250-
watt PowerTune maximum.
At $389, Sapphire’s Radeon HD
6970 (stock settings) is only slightly
more expensive than the GeForce GTX
570, but it surpasses Nvidia’s offering in
every benchmark but S.T.A.L.K.E.R.:
Call of Pripyat. Sapphire’s inclusion of
Battlefield: Bad Company 2 Vietnam
just sweetens the deal. Although it
couldn’t topple the GTX 580, for this
price, AMD has a real winner in the
Radeon HD 6970.
HD6970 2GB GDDR5
BFBC2 Vietnam
Game Edition
$364.99
Sapphire
www.sapphiretech.com
Add To Cart
Customer Review
Specs & Scores
Sapphire Nvidia
Radeon GeForce
HD6970 GTX 580
Price $389.99 $499
Idle Temp 41.6 C 39.1 C
Load Temp 85.2 C 87 C
Max Noise Output
68.5 dBA 65.2 dBA
3DMark 11 Performance
Overall P5275 P6002
Graphics Score 4890 5716
Physics Score 9148 8329
Combined Score
5050 5754
Graphics Test 1 (fps)
21.34 24.95
Graphics Test 2 (fps)
25.88 26.29
Graphics Test 3 (fps)
31.77 36.84
Graphics Test 4 (fps)
14.06 17.96
Physics Test (fps)
29.04 26.44
Combined Test (fps)
23.49 26.77
Games 1,920 x 1,200
Left 4 Dead 2 (8XAA, 16XAF)
119.62 133.29
S.T.A.L.K.E.R.:
Call of Pripyat (4XAA)
35.2 43.22
Aliens vs. Predator (4XAA)
40 43.2
Games 2,560 x 1,600
Left 4 Dead 2 (8XAA, 16XAF)
83.82 88.02
S.T.A.L.K.E.R.: CoP (4XAA)
22.63 27.3
Aliens vs. Predator (4XAA)
25 27.2
Driver: Catalyst 10.11/ForceWare 263.09
Specs: GPU: Cayman XT; Core clock: 880MHz;
Memory: 2GB GDDR5 (1,375MHz); 1,536 Stream
Processors; 96 texture units; 32 ROPs
Test system specs: CPU: 3.33GHz Intel Core i7-980X
EE; Motherboard: Gigabyte GA-X58-USB3; RAM: 6GB
Patriot Sector 7 DDR3; Storage: 128GB Patriot Zephyr
SSD; PSU: Antec TruePower Quattro 1,200W
Article From Computer Power User Magazine
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