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Zotac GTX 970 AMP! Extreme Core Noise Review

The Zotac GTX 970 AMP! Extreme Core Edition that formed the heart of our Quiet SLI Gaming Guide had an excellent cooling solution with a surprising weakness: A high minimum fan speed. An updated BIOS that addresses the issue, so we take another look at its new and improved acoustics.

April 5, 2015 by Lawrence Lee

Product
Zotac GeForce GTX 970 AMP!
Extreme Core Ed. (ZT-90107-10P
)
Graphics Card
Manufacturer
Zotac
Street Price
~US$400

In our most recent of gaming build guide, I assembled a Quiet SLI Gaming PC with a pair GTX 970 graphics cards which proved to be extremely well cooled. Under normal gaming conditions, it managed to keep GPUs under 80°C with stock cooling while maintaining a noise level of just 23 dBA@1m. Achieving such a low noise level with a high-end configuration would have been unfathomable just a year ago, at least not without some serious aftermarket cooling. A few different elements played major roles in attaining this result: the impressive airflow provided by the SilverStone Fortress FT05 case, the superlative energy efficiency of Nvidia’s Maxwell 2 architecture, and the heavy duty heatsink/fans of the two GTX 970s.


The Zotac GTX 970 AMP! Extreme Core Edition x 2.

The Zotac GTX 970 AMP! Extreme Core Edition I used has a few things going for it including a sizable heatsink/fan combination, high clock speeds, and better physical compatibility than most 970s. The PCB measures 26.6 x 10.6 cm with the heatsink/shroud expanding its footprint to 30.0 x 11.1 cm (11.8 x 4.4 inches), making it narrower than many competing models. The board extends just 1.0 cm past the corner of the I/O bracket with the board overhanging it by 0.5 cm and the illuminated name plate on the side jutting out by another 0.5 cm. Many variants of the R9 290/290X and GTX 970/980 have wider dimensions due to larger PCBs, heatsink covers, or heatpipes sticking out, all of which can make them incompatible with smaller enclosures.


Under the hood.

The stock cooler is formidable, featuring five copper heatpipes, a sizable portion of aluminum fins, three 92 mm fans, and a metal plate cooling all the memory chips, VRMs, and other necessary circuitry on the PCB. However, when I put together the SLI rig, the cooling solution proved to be a double-edged sword. Its minimum fan speed was a whopping 1450 RPM, so while I didn’t have to speed up the fans to keep the cards adequately cool on load, the system produced the same level of noise regardless of what it was doing. This is a far cry from cards like the Asus Strix GTX 900 series which can shut its fans off completely. However, recently Zotac informed us of a BIOS update that addresses this issue, so I thought it was worth a second look.

The BIOS and update tool isn’t available from Zotac’s site but can be downloaded from the links below:


Updating the BIOS from the command prompt.

The BIOS update process is fairly straightforward. Before beginning they advise uninstalling previous loaded drivers and cleaning out any remnants using a third party tool (I prefer Display Driver Uninstaller). Then put the update tool and BIOS in the same folder and navigate to it using the Command Prompt (running with Administrator rights). A simple command and confirmation later, and the firmware updates in less than 30 seconds.


GPU Tweak: default fan curve.

GPU Tweak reveals the fan profile has been recalibrated with the minimum setting now at 30% (~1060 RPM) compared to the previous 60% level (1450 RPM).

TEST METHODOLOGY

Test Platform


Our GPU test system.

Measurement and Analysis Tools

Testing Procedures

Our test procedures are designed to determine the power consumption, noise, and heat produced by the card/cooler with the system in various states. In addition to testing under “normal” conditions, we also perform a torture test consisting of FurMark running in conjunction with Prime95 to stress both the graphics card and processor simultaneously. This combination is more demanding on the CPU and GPU than any real gaming session. This final result is not indicative of a real-world situation, but rather a worse-case scenario; If it can cool the card and its components adequately it means there will be some degree of thermal headroom when deployed in a more conventional situation.

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.

Aftermarket coolers are installed on an ASUS GeForce GTX 680 DirectCU II OC, a factory-overclocked single GPU card that draws 225W by our estimates. The stock VRM heatsink is left on if possible. The cooler’s fan(s) is connected to the motherboard (if possible) and its speed is changed to various levels to represent a good cross-section of its airflow and noise performance.

Ambient Noise Level

For noise measurements, our mic is positioned at a distance of one meter from the center of the case’s left side panel at a 45 degree angle.

Our test system’s CPU fan is a low speed Scythe that is set to full speed at all times while the two Fractal 140 mm case fans are connected to case’s integrated fan controller. Three standard speed settings have been established for testing.

GPU Test System:
Anechoic chamber measurements
Case Fan Setting
System SPL@1m
High
24 dBA
Med
15 dBA
Low
12~13 dBA

When testing video cards and coolers with active cooling, the low setting will be used. For passive cards and heatsinks, all three settings will be tested to determine the effect of system airflow on cooling performance.

Estimating DC Power

The following power efficiency figures were obtained for the
Kingwin LZP-1000
used in our test system:

Kingwin LZP-1000 Test Results
DC Output (W)
22.2
41.9
65.5
90.7
149.0
199.6
251.2
300.3
400.9
AC Input (W)
35
56
81
105
166
211
265
322
426

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.

TEST RESULTS

System Measurements: GPU Test System with
Zotac GTX 970 AMP! Extreme Core (Updated BIOS)
State
Idle
Prime95
RE6 Demo (Peak)
Prime95 + FurMark
Prime95 + FurMark
GPU Fan Speed
1060 RPM
1510 RPM
1570 RPM
1120 RPM*
CPU Temp
29°C
40°C
45°C
57°C
58°C
MB Temp
27°C
27°C
38°C
39°C
40°C
GPU Temp
28°C
29°C
63°C
64°C
71°C
GPU Core Clock
135 MHz
1404 MHz
888 MHz
888 MHz
System Power (AC)
40W
78W
216W
228W
228W
System Power (DC)
27W
63W
204W
216W
216W
System SPL@1m
14 dBA
19 dBA
19 dBA
14 dBA
*manually adjusted fan speed
CPU fan at 500 RPM, system fans at 580 RPM.
Ambient noise level: 10~11 dBA
System noise level (on int. graphics): 12~13 dBA
Ambient temperature: 21°C

With a single Extreme Core Edition installed in our less demanding GPU test system, the machine measures just 14 dBA@1m with the updated BIOS. This is only an increase of 1~2 dB compared to the same rig running without a discrete video card. The rest of the components are barely audible so adding this card barely makes a noise impact.

Leaving the fan control on the stock/automatic setting, the GPU fans kick up to 1510 RPM during the most demanding portion of the Resident Evil 6 Demo Benchmark. This, along with some faint coil whine (which sounds mostly like innocuous white noise close up), results in a noise level of 19 dBA@1m, which is still fairly quiet. Our most stressful test, Prime95 + FurMark, only draws 12W more from the wall before the card hits its power limit, so only a slight increase in GPU fan speed is required, though this more prolonged and stable heavy load generates enough hot air to greatly affect the CPU area.

By default, the fans try to maintain a GPU temperature of 63~64°C which is a fairly aggressive goal in my opinion. Overriding the fan, I found that the minimum speed (which is a bit higher than at idle) is more than acceptable, even with this most taxing test. The GPU heats up to 71°C while the noise level returns to 14 dBA@1m, a superb result.

The GPU fans have a lower pitch with a rougher character than our system’s case fans but its not acoustically unpleasant, especially at lower speeds. In any event, the side panel of the case sufficiently dulls the noise it produces such that it sounds more or less inconspicuous. At 1510 RPM, it emits an even-keeled turbulence that is unlikely to bother any but the most noise-adverse.

Comparison: GPU Test System, FurMark + Prime95 @ 75°C
GPU Model
Est. Power Draw (DC)
GPU Temp
GPU Fan Speed
SPL @1m
Zotac GTX 970 AMP! Extreme Core
166W
71°C
1120 RPM
14 dBA
Asus GTX 960 Strix
151W
75°C
1120 RPM
14 dBA
Asus GTX 680
DirectCU II OC
226W
75°C
1200 RPM
17~18 dBA
Asus GTX 980 Strix
198W
75°C
1140 RPM
18~19 dBA
Zotac GTX 970 AMP! Extreme Core
166W
64°C
1570 RPM
19 dBA
Zotac GTX 970 (vanilla)
168W
75°C
2580 RPM
28 dBA
AMD R9 290X (reference)
308W
92°C
2950 RPM
39 dBA
CPU fan at 500 RPM, system fans at 580 RPM.
Ambient noise level: 10~11 dBA
System noise level (on int. graphics): 12~13 dBA
Ambient temperature: 21°C

For a comparison, I present the load results from recently tested cards, with the fan speeds adjusted to achieve a GPU temperature of 75°C (if possible).

The GTX 970 Extreme Core’s cooling solution is so strong, its GPU temperature tops out at 71°C at the new minimum fan speed, generating the same noise level as the GTX 960 Strix, and it runs 4°C cooler despite using 15W of extra power. This is the best cooled graphics card I’ve handled in some time.

Noise Level Comparison: Dual Cards (Idle)
System
GPU Test System
SLI Gaming Build
BIOS
Old
New
Old
New
GPU Fan Speed
1450 RPM
1060 RPM
1450 RPM
1060 RPM
System SPL@1m
20 dBA
15 dBA
23 dBA
19~20 dBA
(estimated)

With dual cards, the acoustic difference between the BIOS’ minimum fan speeds is similar in our GPU test system. Reducing the idle fan speed by ~400 RPM results in a 5 dB drop.

As for our SLI gaming build, I estimated the new noise level rather than putting the entire system back together to check the results of this one change. I set the GPU fans in the GPU test system to 1450 RPM (old BIOS level) and increased the speeds of the system fans until the rig produced the same 23 dBA@1m result I achieved previously with the SLI gaming build. Then I simply put the GPU fan speeds back to normal (updated BIOS level) for the final measurement, which turned out to be 19~20 dBA@1m. This is a substantial reduction which could be improved further by lowering the CPU and system fan speeds as well.

MP3 Sound Recordings

These recordings were made with a high resolution, lab quality, digital recording
system inside SPCR’s own 11 dBA ambient anechoic chamber, then converted to
LAME 128kbps encoded MP3s. We’ve listened long and hard to ensure there is no
audible degradation from the original WAV files to these MP3s. They represent
a quick snapshot of what we heard during the review.

Each recording starts with ambient noise, then 5~10 second segments of product
at various states. For the most realistic results,
set the volume so that the starting ambient level is just barely audible, then
don’t change the volume setting again while comparing all the sound files.

FINAL THOUGHTS

Many products come through our labs that could be vastly improved by a simple change. The Zotac GTX 970 AMP! Extreme Core Edition is such a product, a formidable piece of hardware that was surprisingly unsuitable (in its original state) for quiet systems due to its high minimum fan speed. When a GPU is heavily taxed, you expect a certain level of noise to deal with all that heat but it shouldn’t be noticeable when sitting idle. This affected our SLI Gaming Build twice as hard, which is a shame as the stock cooler is superb when a greater demand is placed upon it.

The updated BIOS rectifies this issue completely, making it a suitable high-end graphics card for quiet machines. The change makes the Zotac GTX 970 AMP! Extreme Core Edition one of the more appealing GTX 970s on the market as it also has a high clock speed, an excellent cooler, and a narrow physique that makes it more compatible with compact cases. If there’s anything left to criticize, it’s the card’s maximum power target of 106%, which is low compared to most of its competitors. This limits how much further the card can be pushed in terms of overclocking, but aside from that, it’s a compelling choice for a high performance graphics card.

Our thanks to Zotac for the GeForce GTX 970 AMP! Extreme Core Edition video card samples.


Zotac GeForce GTX 970 AMP! Extreme Core Edition is Recommended by SPCR

* * *

Articles of Related Interest
Quiet SLI Gaming PC Build Guide

Asus GeForce GTX 960 Strix OC Edition

Arctic Accelero Hybrid II-120 Liquid GPU Cooler

NZXT Kraken G10 Graphics Adapter

Asus GeForce GTX 670 DirectCU II

Asus Radeon HD 7870 DirectCU II

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