Test protocol 2.0 beta
After two and a half years of loyal service, we decided to pension off the Sonata 3 and the first version of our full test protocol dedicated to measuring the thermal characteristics of graphics cards. Over this period we used thermal imaging to examine in detail at no fewer than thirty-seven graphics solutions and this has formed a useful database and given us the ability to position the results of new solutions objectively.
Test protocol 2.0 has also been designed to last and is in fact still under development. This report was a good debugging exercise for us and highlighted some areas which need to be improved.
This new test protocol uses a Cooler Master RC-690 II Advanced casing, radically different to the Sonota 3. With many perforations, it’s also better equipped cooler wise, with a 140 mm suction fan at the front and 120 mm and 140 mm extraction fans at the back, in place of the single 120 mm fan on the Sonata 3.
Instead of the X48 and Q6600, we’re now on a P67 and Core i7-2600 platform. We went for the Asus Sabertooth P67 motherboard which has an additional slot between the CPU and the first graphics port, which makes it easier to take infrared photos. We did however remove its plastic protection which was stopping us from viewing the temperature of various areas of the PCB. While previously we used the Intel boxed cooler, here we went for a Big Shuriken from Scythe, which is more effective and isn’t subject to the size issues you get with tower models, which would have been a problem for taking the photos.
We used a Scythe Kaze Master rheobus to control the speed of the CPU and box fans. The CPU fan was thus fixed at 900 RPM and what we imagined to be 9V for the casing fans, which don’t have speed monitoring.
We opted for a high-end power supply: the Seasonic X850. It has the advantage of being passive when the energy consumption is under 200W, namely when our system is at idle. We used an OCZ Vertex 2 64 GB for the system disk and two hard drives, a Hitachi Deskstar 7200 RPM and a Western Digital Raptor 10000 RPM, as secondary drives.
Thanks go to Asus, Cooler Master, Intel and Seasonic for supplying most of the components required for setting this test system up.
We kept our Fluke Ti25 thermal camera for the readings, which gives us an image of the different temperatures that we also took using the sensors on the Asus Sabertooth. However we have replaced our sonometers with the Cirrus Optimus CR152A Class 2 models that allow us to measure sound levels down to 21 dBA, which is as low as the room allows us to go. The noise level readings are not therefore comparable with the old ones, which went down to a minimum of 35 dBA.
The sonometer was mounted on a base and placed 50 cm from the side of the casing, raised up 25 cm from the table on which the casing was placed. The solutions measured at between 21 and 22 dBA can be considered as silent. Up to 25 dBA and the cooling is very discreet. Between 25 and 30 dBA can be seen as discreet. Between 30 and 35 dBA we have down as standard and between 35 and 40 dBA is starting to get noisy. Anything higher than this is noisy and becomes excessive for a computer, though of course, as with the other thresholds, this is subjective and depends on several factors such as the regularity of the noise and the environment.
This time we decided to measure noise levels both during standard usage of the casing and with the graphics card isolated, turning the hard drives and CPU/casing fans off. This allowed us to differentiate between the least noisy cards in much more detail.
The load test has also moved on. We have replaced the 3DMark06/07 Pixel Shader test, in which fps values went much too high, with the first scene from 3DMark 11. We opted for this one because it doesn’t use tessellation, a rendering technique that could lead to a drop in energy consumption on cards that are saturated at this level. This scene is however 5% less demanding in terms of energy consumption than that in 3DMark06, which worked the texturing units a good deal more. This load test is therefore now very similar to a very demanding game and a good deal different to tests such as Furmark and OCCT in terms of energy consumption. The CPU was loaded with Prime95 on 4 threads, with the lowest priority.
Here’s how we organised the tests:
- Ambient temperature reading to keep it between 25 and 26°C
- 45 minutes at idle
- Temperature sensor readings
- Noise level reading
- Casing is opened rapidly for thermal imaging photo
- Casing closed and two hard drives turned off
- 15 minutes at idle
- All fans are turned off and rapid noise level reading
- Hard drives and fans turned back on
- 45 minutes in load
- Noise level reading
- Temperature sensor readings
- 15 minutes in load
- Casing is opened rapidly for thermal imaging photo
- Casing closed and two hard drives turned off
- 15 minutes in load
- All fans turned off and rapid noise reading
This protocol is still at beta stage and we expect to improve it further, perhaps with the addition of a stage with overclocked cards and another at which the speed of graphics card fans is pushed to 100%. We also plan to modify the speed of the original casing fans between the idle and load phases or even replace them entirely in view of how poor they are, not to mention their lack of monitoring. Even with voltage reduced to 9V, they are still very noisy, with a very pronounced mechanical sound. We measured the level of noise linked to the casing at 34.1 dBA, which is much higher than that of the graphics cards alone at idle.
With the aim of highlighting the differences between the old and new test protocols, we compared the reference GeForce GTX 580 as well as the Zotac AMP²! Edition under both protocols. Note, the reference card expels almost all the hot air from the casing while the Zotac hardly expels any:
At idle, the temperature comparison between the two cards is identical in both protocols. The noise levels are however a good deal higher in the new casing as it's currently configured. While the Sonata 3 wasn’t very noisy at idle (remember the dBA values aren’t comparable), the RC-690 II Advanced is really annoying, in spite of the fact that its fans run more slowly. When the graphics card was isolated however, the new sonometer allowed us to note the difference in noise levels between the two cards more precisely.
In load, both graphics cards benefit from the new test system: they don’t heat up as much and the fan speed can therefore remain at lower levels. However, there’s more of a gain on the Zotac AMP²!, the new casing being a good deal more efficient in terms of evacuating the hot air that it gives off.
