The Zalman Twins: 9500 & 9700 Air Tunnels
by Wesley Fink on February 19, 2007 12:40 AM EST- Posted in
- Cases/Cooling/PSUs
Cooling Results
The Zalman 9500 and 9700 are both excellent performers in CPU cooling at stock speeds. However, as overclocks were raised, neither cooler was particularly outstanding in the ability to cool the CPU under stress conditions. To be as fair as possible all overclocking tests were run with the 9500 and 9700 fans at the highest speeds they could be pushed to with the Fan Mate 2 controller. These fan speeds also generate a great deal more noise than the low speed settings on either cooler.
Where the very good Intel stock cooler keeps the X6800 at 41C at idle, the 9500 can manage an excellent 30C, with the 9700 doing even better at 28C. This is not quite as cool as the Tuniq Tower 120 at stock idle, but it is among the best performance we have seen at stock idle speeds. As processor speed increases, however, the Zalman starts dropping rapidly in efficiency. The higher the speed goes, even at idle, the greater the cooling performance delta between the 9500/9700 and the leading Tuniq Tower 120
At 3.73GHz the retail HSF is running at 56C, compared to 42/38C with the Zalman 9500/9700. The performance at idle with both Zalman cooler is quite good at stock speeds, but performance drops fast with increased CPU overclocking. Both Zalman coolers reach rather average overclocks, considering they are very expensive coolers. The 9500 tops out at 3.81 GHz and the 9700 tops out at 3.83GHz. Many of the top coolers we have tested have done better.
It is easy to measure the effectiveness of a cooling solution at idle - when the computer is doing nothing except running the temperature measurement program. It is more difficult, however, to effectively simulate a computer being stressed by all of the conditions it might be exposed to in different operating environments. For most home users CPU power is most taxed with contemporary gaming. Therefore our stress test simulates running a demanding contemporary game.
The Far Cry River demo is looped for 30 minutes and the CPU temperature is captured at 4 second intervals with the NVIDIA monitor "logging" option. The highest temperature during the stress test is then reported. Cooling efficiency of the Zalman 9500 and 9700 under stress conditions was compared to the retail HSF and other recently tested CPU coolers. Once again the well-regarded Tuniq Tower 120 was the top air cooling solution, with the TEC/air hybrid Monsoon II Lite as the top performer. Both Zalman coolers were very average in performance among the coolers we have tested and well behind the Tuniq and Cooler Master at the top of the air cooling chart.
The Tuniq keeps the CPU at 34C under stress at stock speeds, where the Zalman 9500 manages 39C and the 9700 does better at 36C. However, the same pattern emerges under stress testing that we first saw under idle conditions: as the overclocked CPU speed increases the cooling effectiveness of both Zalman coolers drops rapidly. By 3.83 GHz, which is the highest overclock the 9700 could reach with stability, the Tuniq is at 50C compared to the 5700 at 59C. The 9500 at its highest overclock of 3.81 GHz is at 59C. Both Zalman coolers appear to be optimized for excellent performance at or near stock speeds. While the Zalman coolers are among the top performers in cooling at stock idle and load, as speed increases their effectiveness drops rapidly.
As stated many times, the overclocking abilities of the CPU will vary at the top, depending on the CPU. This particular CPU does higher FSB speeds than any X6800 we have tested, but the 3.9GHz top speed with the Tuniq is pretty average among the X6800 processors we have tested with Tuniq cooling. A few of the other processors tested with the best air coolers reach just over 4 GHz, but the range has been 3.8 to 4.0GHz. Stock cooling generally tops out 200 to 400 MHz lower, depending on the CPU, on the processors tested in our lab. The 3.83 GHz with the Zalman 9700 and 3.81 GHz with the Zalman 9500 - both achieved with the cooler fans at their highest noisie levels - are average at best. We would expect premium-priced CPU coolers to perform better.
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Avalon - Monday, February 19, 2007 - link
Keep up the good work. I'm enjoying watching the list of coolers you guys review grow and grow, and I think it's great that you'll be doing the Scythe Infinity and Ninja soon. I know I've mentioned this before, but I still want to see the Coolermaster Hyper TX if you guys can get your hands on one. Reason being is it looks as though it provides excellent PWM area cooling...which brings me to my next question...Have you guys considered throwing in PWM area temperatures? Some coolers are great at cooling the CPU, but awful at providing air anywhere else...and PWM cooling can help with stability.
Wesley Fink - Monday, February 19, 2007 - link
We agree that PWM is an important consideration, and it is something we will likely visit in a future article. Most of the top motherboards these days use passive sinks on the power transisitors and northbridges, but they also come with cooling fans for use with water cooling and HSFs that do not provide good cooling for board components. The 680i has such a fan and we use it in our testing to try to remove the variable PWM air flow and temps as a performance factor. Of course, that avoids the question by removing the variable, rather than answering it. We will try to address this in some future article, but for now we have a lot more coolers waiting for tests on our standard test bed.acivick - Monday, February 19, 2007 - link
I didn't see it listed anywhere in the review, but I'm assuming that the included thermal compound was used, at least for the 9500/9700. If the same compound was not used for all coolers, they should be retested, as it's not a valid test. Using the same compound on each would make it more of an even playing field and would thus be testing the performance of the cooler only.For instance, MX-1 is supposed to be much better than the stuff Zalman provided, giving a 3-5C decrease in overall temperatures.
Wesley Fink - Monday, February 19, 2007 - link
We use the thermal compound that comes with the cooler in most cases. If it is just a little packet of cheap thermal compound we use our standard, which is a silver colored tube thermal compound of pretty decent performance - not something exotic like MX-1.In the case of the Zalman 9500 and 9700 we used the Zalman Thermal Grease. Before replying to this question I tested the Tuniq Tower 120 with the Zalman Thermal Grease. Results were all but identical to the tests we ran using our bulk silver colored compound.
Over the years I've used many thermal compounds, and if you use a quality product and apply it properly the results have been similar. I hear what you are saying about a 3-5C difference with MX-1, but I certainly have not seen those kinds of gains with any thermal grease. I can also point you to a serious review that shows toothpaste and Vegemite with superior performance to Arctic Silver 5. At some point in the future we might take a closer look at the impact of thermal compounds on performance, but for now I am confident our current test methods are not introducing new variables with sloppy choices of thermal compound. We are prudent in our choices, but not maniacal.
JarredWalton - Monday, February 19, 2007 - link
Except a lot of people use whatever comes with the HSF. Wes would have to explain what thermal compound he's using, but I would assume he's sticking with the included stuff for each HSF where possible. If nothing is included... well, I don't know what he does there. :) Basically, though, I don't think retesting is in order unless he's using high-grade stuff on HSFs that omit the inclusion of a compound.VooDooAddict - Monday, February 19, 2007 - link
I agree that he should make it clear though what he's using.Using the shipped compound with these units would be preferable from complete product a review standpoint. As it stands there's no mention of his cleaning and reapplying new compound either. From a simplicity standpoint of reviewing and a better comparison of coolers, it would be easier to just use one compound for all the coolers to reduce cleaning time and variables.
ozzimark - Monday, February 19, 2007 - link
umm, my 9500 looks NOTHING like that base :-Xhttp://www.eclipseoc.com/image/cooling/zalman%20cn...">click for pic!
dev0lution - Monday, February 19, 2007 - link
Good info. I was leaning towards getting the 9500 since I don't think my 7700-alCu will fit on the eVga 680i board I haven't got around to installing. I might consider getting one of the alternatives now, seeing as how it doesn't look like the zalman's are worth the price premium.Fishie - Monday, February 19, 2007 - link
The Tuniq is 54dBs while the 9700 is 57dBs. Twice as loud? Wouldn't twice as loud be 108dBs? Not to mention the 9700 is quieter than the Tuniq at 24" away.
Wesley Fink - Monday, February 19, 2007 - link
3db is twice the sound energy, since the db scale is logarithmic. At one time twice the energy was considered twice as loud, but recent research shows 6db to 10db increase to be perceived by the human ear as twice as loud - depending on whose study you read. I have stated this in past reviews. To be more precise I changed the wording in the review to twice the sound energy.