The Zalman Twins: 9500 & 9700 Air Tunnels
by Wesley Fink on February 19, 2007 12:40 AM EST- Posted in
- Cases/Cooling/PSUs
Noise
For many enthusiasts upgrading cooling the goal is maximum stable overclock, and they will live with the inconvenience of a louder system. For other users silence is the most important factor, and these users will forgo maximum overclocking if this increase system noise levels. In general the Zalman 9500 and 9700 can be considered very quiet, but performance of either cooler is not standout against the competition - at least where noise is concerned.To test idle and load noise levels, the Zalman fan controller was used to dial in the lowest and highest fan speeds the fan could achieve. Lowest speed results are reported as idle and high speed results are reported as stress noise. These are procedures that we plan to use, if possible, in future CPU cooler reviews. Both sets of results will be reported if there is a significant difference in low-sped and high-speed noise.
There are virtually no power supplies that do not have a fan. While Zalman and a few others do make a few expensive fanless power supplies, we have not seen a fanless unit larger than 500W, or one that would be used for seriously overclocking a system. With that in mind the noise level of the system with all fans turned off except the power supply was measured. The power supply used for the cooling test bed was the OCZ PowerStream 520, which is one of the quieter of the high performance power supplies. The noise level of the power supply was 38.3dB from 24" (61cm) and 47dB from 6" (152mm). The measured noise level of the test room is 36.4dB, which would be considered a relatively quiet room with a noise floor slightly below the OCZ PowerStream 520 PSU.
Measured noise levels in this chart should be considered worst case. Measurements were taken with an open side of a mid tower case 6" from the open HSF and 24" from the open HSF. Real world would be a completely closed case with a further reduction in noise.
Zalman, silence and low-noise all go hand-in-hand in the mind of most computer users, so Zalman is expected to be the standard against which others are measured. Put another way, noise is an area where Zalman is expected to top the charts. The Zalman 9500 and 9700 both exhibited noise levels below the system floor at idle speeds measured 6" and 24" from the cooler. This is typical performance with most of the heatpipe towers we have tested in recent weeks.
However, when pushed to the highest speeds available under stress conditions, the noise levels of the 9500 and 9700 were average at best. Neither Zalman was particularly quiet at high speed, and the 9700 was one of the noisiest coolers we have tested in the lab at 2800 RPM - 3db is twice the sound energy of the Tuniq Tower 120 at high speed and almost as loud as the Monsoon II Lite which is plagued by buzzing and clicks from fan switching. On low speed the 9500 and 9700 are very quiet, as are most heatpipe towers, but higher fan speeds yield much higher noise.
The measurements we made are also what you will get with either Zalman, since the fans are custom and embedded in the Zalman design. Zalman did not design the fans to be replaced with other 92mm (common size) or 110mm (Uncommon size fans). All-in-all the Zalman 9500 and 9700 were competitive with other tested coolers in noise levels, but they were not stand-out in any way. This is a reflection of how far the competition has come in addressing noise concerns in the PC environment.
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Scorpion - Wednesday, February 21, 2007 - link
Page 5 states:So for 30 minutes, you capture 450 data points. It's expected that the data will ramp up over the 30 minute interval and reach an approximately linear stability region towards the end.
I have a problem with your measurement evaluation and findings. I do not think this is a very conclusive or accurate measurement and evaluation criteria. This information could be useful, yes, but only as an additional evaluation criteria.
All tests need a good, quantifiable evaluation metric. The "goodness" of a test is only as good as that metric. And I conclude that what you've chosen is a poor metric. Your posterior evaluation is highly influenced by noise. The maximum could be the result of a large noise addition to the measurement.
A better choice would have been to analyze the data results from all the tests to determine a stability region in the latter part of the data measurements, for all tests. Treat the data in that region as a random variable and take the expectation over that region. That would give you a much better evaluation criteria. You could also compute the variance of the data in this region to determine how stable the performance is for each cooler. This could also be a useful metric, although I know that this may not mean much to your typical audience. Another interesting metric would be to evaluate the other region in the data, in order to measure how quickly temperature ramps up. Or put into other words, how quickly each fan responds to temperature changes.
I'm saddened to see a good and useful article brought down by it's poor evaluation criteria. It effectively reduces the confidence in your conclusions.
Wesley Fink - Friday, February 23, 2007 - link
We try to answer two questions in our cooling tests. First, most users beef up cooling to improve overclocking. We determine the highests stable overclock using a standard CPU/test bed by finding the overclock the cooler can maintain for 30 minutes of looping a demanding game. The highest OC is a very good measure of the effectivenes of the cooler and is compared to other coolers. We also measue and report the highest temperature in this load condition - and yes it does spike up and level off as you suggest. We haven't seen the huge spikes you might fear are there in our test data. Temps rise quickly and stabilize at the temp we report. This is a good indication of cooler efficiency.Second, some users beef up cooling to reduce noise. We also report the lowest noise measurements for the cooler we are testing.
Your suggestions would provide much useful information, and we may add additional testing in the future. However, for now, we are trying to cut through all the hype surrounding cooler testing and provide as much useful info to our readers as possible in a timely manner. We are comfortable that we answer the two questions above in our cooler reviews, and those are the main questions our readers are always asking us about cooler performance.
cyberkost - Tuesday, February 20, 2007 - link
I did not quite get the methodology of the noise level comparisons...Were the coolers required to provide "same cooling performance" (e.g., same CPU temperature some long time into running some stress test)? It does not seem that they were. I'm worried about Anandtech intending to adapt the noise-comparison technique described in this article. The proper technique (IMHO) would be:
1) install cooler
2) run a stress test
3) dial cooler RPM till a (judiciously) chosen (same for all coolers) CPU temperature is achieved (say 40C) in a stable manner
4) record the noice level and put it on the comparison chart
strikeback03 - Tuesday, February 20, 2007 - link
Reading the respective reviews, it would appear that at stock speeds (and possibly some others) that the Katana, for example, does not get as cool as the Tuniq even when the Katana is at max RPM and the Tuniq at minimum.rjm55 - Tuesday, February 20, 2007 - link
Can you please review the Austrian Noctua NH-U12. I've seen good and bad reviews and I want to see what you find.gloutch - Tuesday, February 20, 2007 - link
The performance of those headpipes coolers is reduced if not properly oriented.SO: What was the position of the Zalmann coolers during the test ????????????????????
Wesley Fink - Tuesday, February 20, 2007 - link
From page 4 - CPU Cooling Test Configuration:"All cooling tests are run with the components mounted in a standard mid-tower case. The idle and stress temperature tests are run with the case closed and standing as it would in most home setups. We do not use auxiliary fans in the test cooling case, except for the north bridge fan attached to the 680i for overclocking."
As an aside we have found the impact of heatpipe cooler orientation to be pretty small - we just don't leave that test criteria to chance. An article on the impact of heatpipe cooler orientation on performance could be interesting.
orion23 - Monday, February 19, 2007 - link
Hi!Thanks for this awesome review. Only 2 top coolers left to review:
Thermalright Ultra 120
Scythe Infinity!
It is great to see Anandtech starting to review other PC components such as CPU Coolers and RAM. Things can be very quiet around here unless a new CPU, GPU or MotherBoard comes along......
Hopefully this is only the beginning of a new Anandtech that will review other important PC components such as the PSU, CPU Coolers, (AIR / Water), Fan Controllers...
It wouldn't hurt to have more stuff to read around here!
DrMrLordX - Tuesday, February 20, 2007 - link
Actually, the SI-128 and Noctua NH-U12F probably deserve a review at some point as well. Maybe even the Scythe Mine? The Mine can supposedly outperform the Ninja when using high-cfm fans, but your guess is as good as mine when it comes to actually mounting a 120mm fan on the Mine that normally takes a 100mm fan.DrMrLordX - Tuesday, February 20, 2007 - link
Woops, I forgot the Big Typhoon and Big Typhoon VX.