http://www.maximumpc.com|JAN 2011 |MAMAMAXIMXIMXIMXIMUUUUMMPPPCC| 81
instead of the dual mini-DisplayPorts that AMD
envisioned, and XFX’s custom cooler delivers
better airfl ow. The GPU and 1GB frame buff er
on this card are clocked at the stock rates of
775MHz and 1,000MHz, respectively.
The Radeon HD 6850 is manufactured
using the same 40nm process as the Radeon
HD 5850, but the die size is much smaller
(255mm^2 versus 334mm^2 ). The new chip has
480 fewer stream processors and 24 fewer
texture units, but its ROP count remains the
same and its core clock speed is considerably
higher (775MHz compared to 725MHz). In
spite of this, the card consumes much less
power at idle and under load, and requires
just one 6-pin power connector.
In terms of performance, XFX’s stock-
clocked Radeon HD 6850 held up very well
against overclocked Nvidia GeForce GTX 460
cards with 768MB and 1GB frame buff ers, as
well as an overclocked Radeon HD 5850. That
makes the power-consumption numbers all the
more remarkable.
But other than the redesigned heatsink and
fan, that leaves XFX’s excellent warranty as the
only other justifi cation for the $20 premium
XFX expects to fetch over AMD’s retail price
guidance. Is it worth it? That’s up to you.VERDICT$200, http://www.xfxforce.com^8
XFX RADEON HD 6850XFX RADEON HD 6870
It’s obvious that 6870 is 1,000 better than 5870,
right? Of course not. AMD’s second second-gen
DX11 part is not AMD’s new top-shelf GPU.
Instead, the HD 6870 is more comparable to
the older HD 5850, but it’s much cheaper and
consumes considerably less power. It’s not
about fratricide with AMD though—the real
targets are Nvidia’s mid-priced 768MB and 1GB
GeForce 460 GPUs.XFX’s take on the Radeon HD 6870 hews
much closer to AMD’s reference design and
features a mounting bracket with two mini-
DisplayPort 1.2 connectors, one HDMI 1.4a, one
dual-link DVI, and one single-link DVI. XFX’s
core and memory clock speeds are also the
same as AMD’s reference design: 900MHz and
1,050MHz, respectively.
The spec chart helps explain why the
Radeon HD 6870 fails to overcome the older
high-end part: The new GPU has 480 fewer
stream processors, 24 fewer texture units, and
its 1GB of GDDR5 memory runs at a slower
clock speed (1,050MHz versus 1,200MHz). The
6870’s core clock speed, on the other hand, runs
50MHz faster than the older 5870 (900MHz
versus 850MHz).
Despite running at reference-design
clock speeds, XFX’s take on the Radeon
HD 6870 delivered impressive benchmarks
compared to the overclocked 768MB and
1GB GeForce GTX 460 cards we tested, aswell as an overclocked Radeon HD 5870.
The Radeon HD 6870 boasts an exceptional
price/performance ratio, with an even more
impressive performance-per-watt ratio. This
card is most defi nitely a winner.VERDICT$250, http://www.xfxforce.com^9
XFX RADEON HD 6870The XFX 6870 gives you a ton of output options.SPECS
Radeon Radeon
HD 6850 HD 6870
Die Size (mm^2 ) 255 255 255255
Transistor Count 1.7 Billion 1.7 Billion1.7 Billion 1.7 Billion
Memory Bandwidth 4Gbps 4.2Gbps4Gbps 4.2Gbps
Stream Processors 960 960 1,1201,120
Texture Units 48 48 5656
ROPs 32 32 3232
Core Clock (MHz) 775 775 900900
Memory Clock (MHz) 1,000 1,0501,000 1,050
Memory 1GB GDDR5 1GB GDDR51GB GDDR5 1GB GDDR5
Power (watts idle/load) 19/127 19/15119/127 19/151
Power Connectors One 6-pin Two 6-pinOne 6-pin Two 6-pin3DMark Vantage Perf 14,292 17,068 14,225 15,514 19,282 13,737 14,609 15,412
Unigine Heaven 2.1 (fps) 16 19 13 14 13 18 18 24
Crysis (fps) 24 29 21 26 33 19 18 14
BattleForge DX11 (fps) 36 42 30 42 45 38 37 50
Far Cry 2 / Action (fps) 67 65 42 53 66 56 54 68
Far Cry 2 / Long (fps) 68 78 47 61 78 68 66 83
HAWX DX10 (fps) 62 73 50 76 92 63 65 86
STALKER: CoP DX11 (fps) 28 34 26 30 38 25 30 32
Just Cause 2 (fps) 30 35 26 32 37 30 31 33
Aliens vs. Predator (fps) 23 27 19 25 31 21 22 30
Power @ idle (W) 133 129 137 142 141 128 131 161
Power @ full throttle (W) 218 254 241 290 283 248 251 353Best scores are bolded. Our test bed is a 3.33GHz Core i7-975 Extreme Edition in an Asus P6X58D Premium motherboard, with 6GB of DDR3/1333 and an 850TX Corsair PSU. The OS is 64-bit Windows 7 Ultimate. All games are run at 1920x1200 with 4x AA.
BENCHMARKS
XFX Radeon XFX Radeon XFX Radeon Asus Radeon HIS Radeon Asus GTX Gigabyte EVGA
HD 6850 HD 6870 HD 5830 HD 5850 HD 5870 460 768MB GTX 460 1GB GTX 470