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Sapphire HD 7750 Ultimate Edition

Taking advantage of the AMD’s Radeon HD 7750 low 55W TDP, Sapphire has outfitted it with a fanless cooler. The HD 7750 Ultimate offers silent operation for only US$15 more than actively-cooled versions of the same card.

Sapphire HD 7750 Ultimate Edition

March 18, 2012 by Lawrence Lee

Product
Sapphire HD 7750 Ultimate
PCI-E Graphics Card
Manufacturer
Sapphire
MSRP
$125

A few months ago, AMD launched the HD 7000 series of graphics cards to much fanfare. As with previous generations, the top models were released first, the US$449 HD 7950 and US$549 HD 7970, to garner positive press for mind-blowing high resolution and multi-monitor gaming performance. More mainstream cards followed in the wake of this applause — like the US$110 HD 7750, pitiful by comparison to the early high-end releases, but a piece of hardware that will ultimately find its way into many more systems. The lower-end GPU boasts very modest power draw, allowing Sapphire to produce a completely fanless version, the HD 7750 Ultimate, which is the subject of this review.

Sapphire has been making Ultimate edition fanless graphics cards for a long time, going back all the way to the Radeon 9000 series in 2003. Back then, they simply slapped on Zalman’s famous VGA heatpipe cooler, but today they design their own passive cooling solutions. The HD 7750 Ultimate has the same specifications as the reference design, including the scant 55W TDP, so it shouldn’t take a lot to cool without a fan. Obviously you could do this with an aftermarket cooler to replace a stock fanned one, but it is probably not worthwhile: The HD 7750 is currently selling for about US$125, only $15 more than the various actively-cooled versions of the same card.

Sapphire HD 7750 Ultimate: Specifications
(from the product
web page
)
Model
Radeon HD 5750/6750*
Radeon HD 5770/6770*
Radeon HD 7750
Radeon HD 7770
Fabrication Process
40 nm
40 nm
28 nm
28 nm
Transistor Count
1.04 billion
1.04 billion
1.5 billion
1.5 billion
Die Size
166 sq. mm
166 sq. mm
123 sq. mm
123 sq. mm
Shader Units
720
800
512
640
Core Frequency
700 MHz
850 MHz
800 MHz
1000 MHz
Memory Frequency
1150 MHz
1200 MHz
1125 MHz
1125 MHz
TDP
86W
108W
55W
80W
Street Price
US$80
US$100
US$110
US$155
*HD 6750/6770 are rebranded versions of the HD 5750/5770

The HD 7750 and 7770 are based around the new GCN (Graphics Core Next) architecture, packing 44% more transistors into a die 74% of the size of its HD 5000/6000 predecessors thanks in part to the substantial conversion from a 40 nm to 28 nm manufacturing process. With these improvements comes a drastically lower TDP with the HD 7750 rated for only 55W. Though the name suggests it is a replacement for the HD 5750, the current street price positions it above the HD 5770 despite slightly lower clock/memory speeds and 36% fewer shader units, which are critical for performance.


The Sapphire HD 7750 Ultimate box.

The blue exterior is simply a cover, hiding a second plain cardboard box holding the package contents. The video card itself is well protected in a thick foam compartment. Included with the card is a manual, a driver disc, a DVI to VGA adapter, and, surprisingly, an HDMI cable (note: the HDMI cable not listed in the specifications).


Package contents.

PHYSICAL DETAILS

The Sapphire HD 7750 Ultimate has a hefty, impressively-sized fanless heatsink. The card takes up two expansion slots and weighs 450 grams (about 1 lb), with the heatsink accounting for 310 grams.


The bulky two heatpipe cooler extends past the edge of the card lengthwise by 2.5 cm (one inch). The PCB itself is only 16.7 cm (6.6 inches) long.


The heatsink is separated in two pieces held together in part by a black metal plate. The fins of the two sections are oriented perpendicular to each other but they are all approximately 0.28 mm thick and spaced 1.77 mm on average. The heatpipes are 6 mm thick.


Output ports: DisplayPort, HDMI, DVI-I. Widthwise, the cooler extends 14 mm past the edge of the PCB.


The smaller portion of the cooler wraps around the edge of the card, extending 15 mm above the trace side of the PCB. The heatsink is held on by four spring-loaded screws in the same pattern as previous Radeon HD series cards.


The GPU core makes contact with a small rectangular copper base soldered to the rest of the aluminum heatsink. Helping to keep the two heatsink sections together are a pair of fused horseshoe-shaped metal pieces.


The PCB has a fairly clean layout. The memory chips and VRMs are covered with extremely low profile heatsinks.

TEST METHODOLOGY

Our test procedure is an in-system test, designed to:

1. Determine whether the cooler is adequate for use in a low-noise system.
By adequately cooled, we mean cooled well enough that no misbehavior
related to thermal overload is exhibited. Thermal misbehavior in a graphics
card can show up in a variety of ways, including:

  • Sudden system shutdown, reboot without warning, or loss of display signal
  • Jaggies and other visual artifacts on the screen.
  • Motion slowing and/or screen freezing.

Any of these misbehaviors are annoying at best and dangerous at worst —
dangerous to the health and lifespan of the graphics card, and sometimes to
the system OS.

2. Estimate the card’s power consumption. This is a good indicator of how efficient
the card is, and it affects how hot the GPU runs. The lower the better.

3. Determine how well the card decodes high definition video.

Test Platform


GPU-Z screenshot.

Measurement and Analysis Tools

Estimating DC Power

The following power efficiency figures were obtained for the
Seasonic S12-600
used in our test system:

Seasonic S12-500 / 600 TEST RESULTS
DC Output (W)
65.3
89.7
148.7
198.5
249.5
300.2
400
AC Input (W)
87.0
115.0
183.1
242.1
305.0
370.2
500
Efficiency
75.1%
78.0%
81.2%
82.0%
81.8%
81.1%
80%

This data is enough to give us a very good estimate of DC demand in our
test system. We extrapolate the DC power output from the measured AC power
input based on this data. We won’t go through the math; it’s easy enough
to figure out for yourself if you really want to.

Video Test Suite


1080p | 24fps | ~10Mbps
H.264:
Rush Hour 3 Trailer 1
is a H.264 encoded clip inside an
Apple Quicktime container.

1080p | 24fps | ~14Mbps

H.264: Space is a 1080p x264 clip encoded from
the Blu-ray version of an animated short film. It features a hapless
robot trying to repair a lamp on a spaceship.


720p | 25fps | ~2Mbps

Flash: Iron
Man Trailer #1
is the first trailer from the feature film
of the same name. It’s a YouTube HD video, though technically it
is not quite 720p.

Testing Procedures

Our first test involves monitoring the system power consumption as well as CPU and GPU temperatures using SpeedFan and GPU-Z during
different states:

  • Idle,
  • Under load with CPUBurn to stress the processor,
    and
  • CPUBurn plus FurMark to stress both the CPU and GPU simultaneously.

This last state is an extremely stressful, worst case scenario test which generates
more heat and higher power consumption than can be produced by a modern video
game. If the card can survive this torture in our low airflow system, it should be
able to function normally in the vast majority of PCs.

If the heatsink has a fan, the load state tests are repeated at various fan
speeds (if applicable) while the system case fan is left at its lowest setting
of 7V.

If the card utilizes a passive cooler, the system fan is varied instead
to study the effect of system airflow on the heatsink’s performance.

Our second test procedure is to run the system through a video test suite featuring
a variety of high definition clips played with PowerDVD and Mozilla Firefox (for Flash video). During playback, a CPU usage graph is created
by the Windows Task Manger for analysis to determine the average CPU usage.
High CPU usage is indicative of poor video decoding ability. If the video (and/or
audio) skips or freezes, we conclude the GPU (in conjunction with the processor)
is inadequate to decompress the clip properly. Power consumption during playback
of high definition video is also recorded.

Finally we run a few gaming benchmarks to get a general idea of the GPU’s 3D performance.

TEST RESULTS

Baseline with Integrated Graphics: First, here are the results of
our baseline results of the system with its integrated graphics, without
a discrete video card. We also need the power consumption reading during
CPUBurn to estimate the actual power draw of the discrete card later.

System Measurements:
VGA Test System (IGP)
Measurement
Idle
CPU Load
CPU Temp
33°C
51°C
SB Temp
33°C
41°C
SPL@1m
13 dBA
System Power (AC)
52W
140W
System Power (DC, est.)
unknown
111W
Ambient temperature: 22°C
Ambient noise level: 11 dBA

System with Sapphire HD 7750 Ultimate:

As the Sapphire HD 7750 Ultimate is passively cooled, the measured noise level below was generated by the rest of our test system components. It is a very quiet machine with just one Nexus and two Scythe Slip Stream fans. Like many modern video cards, the HD 7750 Ultimate produced some coil whine on load, but it was too soft to be picked up by our mic and inaudible from a one meter distance.

System Measurements: VGA Test System
(Sapphire HD 7750 Ultimate)
State
Idle
CPU Load
CPU + GPU Load
System Fan Speed (SPL@1m)
7V (12~13 dBA)
9V
(16 dBA)
12V
(20~21 dBA)
CPU Temp
29°C
51°C
53°C
49°C
47°C
SB Temp
36°C
41°C
44°C
42°C
40°C
GPU Temp
36°C
39°C
67°C
63°C
60°C
System Power (AC)
60W
149W
188W
186W
186W
System Power
(DC, est.)
unknown
119W
153W
151W
151W
Ambient temperature: 22°C

The HD 7750 Ultimate GPU stayed well under 70°C on load even with only a single case fan undervolted to 7V, a level that made the system almost inaudible. This is impressive, considering FurMark is a highly demanding synthetic torture test that exceeds the stress level of modern games, and our test system is about as airflow-starved as you can get. Increasing the system fan speed resulted in marginal thermal improvements. We also saw only a 2°C increase in CPU temperature while stressing the GPU, so there wasn’t much heat wafting upwards from the video card. The power consumption levels were also quite stingy. The system pulled 39W more when stressing the GPU, compared to the CPU on load alone.

POWER CONSUMPTION

The power consumption of an add-on video card can be estimated by comparing
the total system power draw with and without the card installed. Our results
were derived thus:

1. Power consumption of the graphics card at idle – When CPUBurn is
run on a system, the video card is not stressed at all and stays idle.
This is true whether the video card is integrated or an add-on PCIe 16X device.
Hence, when the power consumption of the base system under CPUBurn is subtracted
from the power consumption of the same test with the graphics card installed,
we obtain the increase in idle power of the add-on card over the
integrated graphics chip.

2. Power consumption of the graphics card under load – The power draw
of the system is measured with the add-on video card, with CPUBurn and FurMark
running simultaneously. Then the power of the baseline system (with integrated
graphics) running just CPUBurn is subtracted. The difference is the load power
of the add-on card. Any load on the CPU from FurMark
should not skew the results, since the CPU was running at full load in both
systems.

Both results are scaled by the efficiency of the power supply (tested
here
) to obtain a final estimate of the DC power consumption.

Note: The actual power
of the add-on card cannot be derived using this method because the integrated graphics may draw
some power even when not in use. We estimate that the integrated HD 4200 graphics chip in our test configuration uses 3~4W. However, the relative difference between the cards should be accurate.

With an estimated idle power of 8W, the HD 7750 Ultimate used a third of that of the Asus EAH5750 Formula. On load, it consumed about half of the HD 5750’s 77W. This a substantial improvement if the two cards are indeed comparable in performance.

Video Playback

As the HD 7000 series features the same UVD 3.0 chip as the previous generation, there were only negligible differences in CPU utilization during HD video playback. Much of the work is offloaded to the GPU. However, as the 7750 has a lower idle power draw, it managed to edge out budget variants of the HD 6000 series in power consumption.

3D Performance

While 3DMark is a completely synthetic benchmark, it is a good general indicator
of 3D performance, particularly when the score differences are quite high. In this case, we see the HD 7750 only pulling slightly ahead of the HD 5750 in both 3DMark11 and 3DMark Vantage.

At 1680×1050 resolution with high levels of detail, the HD 5750 and HD 7750 were basically neck and neck in our three game benchmarks. Most users consider 30 fps as representing a smooth gaming performance, and both cards seem to deliver at this resolution. There are more — and less — demanding titles than these three, but 1680×1050 seems to be the maximum optimal resolution for a ~US$100 card.

FINAL THOUGHTS

Gaming: The HD 7750 offers similar performance to the HD 5750/6750. Users can expect fairly good framerates at 1680×1050 in most games, but anything higher would probably be pushing it. For more extensive 3D testing of the HD 7750, we encourage you to check out more gaming-oriented reviews at sites
like Guru3D, HardwareCanucks or AnandTech.

Video Playback: Video playback remains unchanged in the HD 7000 series, as the same capable UVD 3.0 decoder from the HD 6000 series is present. You can expect the usual goodies including H.264/VC-1 acceleration, bitstreaming for Dolby TrueHD and DTS-HD MA audio, stereoscopic 3D, etc.

Power Consumption: By our estimates, the HD 7750 uses about 8W when idle and up to 42W on full load, though these figures may be slightly higher for versions of the GPU with less extravagant cooling. Its energy efficiency is amazing when you consider that it uses just 55% of the power the HD 5750 consumes on load.

Cooling: The massive fanless heatsink is what separates the Sapphire Ultimate edition from the other the HD 7750 cards. Given the GPU’s low power demands, the cooler is larger than it needs to be, but the extra bulk certainly doesn’t hurt. In our thermally-demanding test system, the GPU never peaked past 70°C and produced no noise.

Price: Currently selling for US$125, the Sapphire HD 7750 Ultimate is a very good deal compared to other HD 7750 models, which can be found for around US$110. Fifteen dollars is a minuscule premium to pay for an upgraded fanless cooler. But there is a bit of a problem with the pricing of the HD 7750 in general. The previous generation HD 5750/6750 cards offer the same performance for about US$80. Yes, the HD 7750 is more energy efficient, but are these differences enough to justify paying 38% more? In addition, you can acquire an HD 5770/6770 for just US$90, which is a step up in performance from both cards.

There’s no question that the Sapphire HD 7750 Ultimate deserves our recommendation, given its no noise performance and low power consumption. Only the value question holds it back from an Editor’s Choice award.


Sapphire HD 7750 Ultimate is Recommended by SPCR

* * *

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* * *

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