Scaling of Cooling Performance

The Thermalright Ultra 120 Extreme has been the top performer so far in CPU cooling at stock speeds. As overclocks were raised, the performance the Ultra 120 with the Scythe SFLEX fan maintained its cooling advantage. The OCZ Vindicator is average or below average in cooling efficiency with the stock fan. It is clear the stock fan was selected for low noise and not cooling efficiency. However, a swap to the 14 dB-A 72 CFM SilenX fan improved cooling to the levels of the Cooler Master Hyper 6+ and Scythe Infinity - two coolers that reached upper tier cooling performance in our reviews.


At 2.93GHz the retail HSF is running at 41C, compared to 32C with the OCZ Vindicator with the stock fan. This is a delta of 9C. The SilenX drops that temperature to 29C, or a delta of 12C. The delta increases slightly with the stock fan as the overclock increases. At 3.73GHz the idle with the retail fan is 56C compared to the Ultra 120 at 46C - a delta of 10C! Performance improvements are much greater with SilenX fan on the OCZ Vindicator. At 3.73GHZ the SilenX cools to 42C, while at the highest stable overclock of 3.90GHz the Vindicator/SilenX is at 44C. This almost straight line at idle at the top of our testing is an indication the SilenX is effectively cooling at idle all the way to the top speed that could be reached in benchmarking.

Cooling efficiency of the Vindicator, with stock and SilenX fans, was next tested under load conditions. Results are compared to the retail HSF and other recently tested CPU coolers. The OCZ Vindicator with the SilenX fan generated results similar to the Scythe Infinity with Push-Pull fans and reached the upper tier of overclocking performance. Results with the single stock fan were average at best.


By 3.90 GHz - the highest overclock the Tuniq, Thermalright Ultra 120, and Cooler Master Hyper 6+, and push-pull Scythe Infinity could reach with stability - the Vindicator is at 65C with the SilenX fan. This is still worse performance than many of other top coolers at this speed. The Tuniq and Ultra 120 are both at 51C, which is some 14C lower than the Vindicator. Keep in mind that the Vindicator was completely stable at 3.90GHz with the SilenX fan even though it ran a bit warmer. The stock fan could only manage 3.80GHz so the SilenX is a much better fan for overclocking the OCZ Vindicator.

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 top tier heatpipe towers 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.

Cooling at Stock Speed Overclocking and Noise
Comments Locked

41 Comments

View All Comments

  • Chunga29 - Thursday, April 5, 2007 - link

    I have to wonder if part of the issue might be your sound meter. Some meters are only good to measure levels down to ~35 dB. I've played with a sound meter at work (the HR department had to conduct "ergonomics testing" [rolls eyes], and as the IT guy I had to make sure the PCs weren't "too loud". Not sure what we were supposed to do if the Dell systems made too much noise for comfort, though....) Our offices were at a pretty consistent 45-50 dB during the day. Even a normal conversation would jack that level up to 55-65 dB (depending on the speaker(s).

    At night with all the computers shut down, however, the noise level dropped below 30 dB and our meter was no longer useful as far as I could tell. Of coruse, at that point even moderate breathing in the vicinity of the meter would increase the detected noise level, as would walking. In my experience, then, 30 dB is basically extremely quiet (even "silent"), and anything lower than that is not likely to be meaningful unless you are testing in some soundproof location.

    I would think in a standard house with all of the noise generating equipment (fans, refrigerators, heat/AC, TV, etc.) shut down that reaching 25 dB should not present a problem. Whether your equipment can reliably measure noise levels at that point is the real question.
  • Wesley Fink - Thursday, April 5, 2007 - link

    CORRECTED - Editors would also like to be able to edit their comments :)

    It seems that every cooler or hard drive review that we have recently posted is met with rocks from SilentPC "readers". This is really puzzling, since we have stated many times that we admire the good SPC has done in making manufacturers pay much more attention to the noise their components generate. There are many more choices of low-noise components because enthusiasts and sites like SPC have pointed out the noise offenders, and buyers have bought the quieter version instead.

    Testing component noise in isolation provides useful information, but AnandTech has a long tradition of "Real World" testing. Overclocking also has very different demands than building the quietest PC to run at stock speeds. The noise floor for any working system will be the power supply generally, and possibly the video card or ambient room noise. It doesn't matter in our approach how quiet a fan is if the power supply is 20db louder. This is pretty obvious but it is rarely mentioned when people are screaming about a fan at 14dbA versus a fan at 18dbA or hard drives that are 2db apart at 26db. Does it really matter if the power supply in the system is at 36dbA?

    We do plan to move to a quieter power supply in our test bed as soon as we can find one that meets our needs. We have looked at several of the power supplies proclaimed in comments in past reviews as "MUCH quieter than the OCZ PowerStream 520W". They were quieter at idle, but at load those power supplies were virtually the same noise level as the OCZ. Idle noise might matter if you sleep in the same room with your computer, but you can't do anything with an idling computer except look at it. We believe the normal operating noise measurements are the noise levels that matter most.

    If readers prefer the review approach of another site that is their right, but we do hope they will stop investing so much emotion in their comments. We think there is room for both the component isolation approach and the AnandTech "real world" approach. We also don't think there is any "right" or universal truth to be gleaned here - they are just different approaches.

    We chose the SilenX fan because it specified higher output than the SFlex at noise levels that were far below our system noise floor. We could just as easily have used the SFlex with a specified 63.7cfm instead of the 72cfm of the SilenX. However, since we have not yet done our fan review we didn't want to tilt sentiment too strongly to one brand name so we chose another quality product to put another deserving brand in the spotlight.

    Our plan going forward is to complete a few more waiting cooler reviews, and then select the top air cooler from our reviews. This will be followed by a fan roundup testing fans on our top performing HSF. New reviews will then be tested with stock components PLUS the top fan from our roundup. This should provide some consistent answers to some valid real-world questions.
  • Wesley Fink - Thursday, April 5, 2007 - link

    Yes, it appears SPCR had the SilenX wars recently, but the fan in this review is NOT the same one tested at SPCR. Someone needs to back away and also point out that while the SilenX fan did not match it's noise specs in the SPCR review it DID test at less than 18db, which is still exceptionally quiet. In addition a recent SPCR review of the 14DBa SilenX power supply concluded "The SilenX 14 dBA advances the state of quiet fan-cooled power supplies by another few decibels."

    The SilenX DID improve the cooling ability and the overclocking ability of the OCZ Vindicator compared to the stock fan, and it did so at measured noise levels below the noise floor of our system. These things we did confirm in our review. We did not test the claimed specifications since our concern was cooler performance, overclocking, and noise lower than our system noise floor.
  • ATWindsor - Thursday, April 5, 2007 - link

    Less than 18 dba at 10 cfm that is, at full speed it is noticably more noisy. (the SPCR-test puts it at 33 dba), I have myself measured fans, and the specs are more or less hit and miss, my conclusion was that the very best indicator of noise is the rpm of the fan. 14 dba isn't even close to realistic at stock speed. Hower also SPCRs reults are not entirely reliable at levels below 20 dba, that is very quiet for a room not specifically designed for it, and most sound-level-meters (even good ones), have a noise floor on the 15 dba-range.

    The problem is that nobody knows how these numbers are measured, 14 dba at what range? 20 meters? It like saying "this heater will give you a room-temperature of a 100 degrees F. Its more or less meaningless when you now nothing about the room, as a heater, sound should be stated as sound-power. Then you can easily calculate sound pressure level in a given room at a given distance.
  • coldpower27 - Thursday, April 5, 2007 - link

    Are you going to be doing some comparisons to the value coolers?
    Sunbeam Silent Whisper Socket 775
    Arctic Cooling Freezer 7 Pro
  • Wesley Fink - Thursday, April 5, 2007 - link

    A value cooler roundup is planned for the future.
  • Bumtrinket - Thursday, April 5, 2007 - link

    I think what's got up SPCR readers' collective noses is the way you allowed SilenX's claim to pass without challenge, and presented it as established fact: "Replace the stock fan with the quiet (14 dB-A) and powerful (72 CFM) SilenX IXTREMA 120 and the Vindicator can overclock with the best." Unless there's some way SilenX have found to defy the laws of physics, there's no way a fan capable of shifting that much air could be that quiet.

    I'm not sure if you're aware of SilenX's history of deceit as regards SPCR, but that was like a red rag to a bull.

    Incidentally, you state that the Scythe Ninja needs a mounting bracket for use with Socket 775 mobo's - that's not true, as it's used the standard Intel pushpin method since revision B was launched several months ago. I'm a bit surprised you consider this would be "good news," especially in a heatsink of this size and weight.
  • Wesley Fink - Thursday, April 5, 2007 - link

    Easy mounting is always good news, but there are valid concerns about the huge weight being supported by something as flimsy as pins. That concern is also stated in the review.

    I have the Ninja Plus Rev. B in for review and the bracket and instructions for the AMD AM2/754/939/940 is NOT a push pin install. For AMD the bracket attaches and clips onto the center pin of the AMD mounting cage - which is supported by screws and a back plate. You still do not need to remove the board or the "cage" to install the Nija Plus Rev. B on an AMD board. THe bracket for Intel 775 IS push pin, but it is the only push pin solution.
  • Bumtrinket - Thursday, April 5, 2007 - link

    ermm... OK, but I was referring specifically to socket 775, not AMD. It's hardly worth arguing about, but you might want to correct what you actually said: "The good news is the OCZ Vindicator comes preconfigured for Intel Socket T, where the Scythe requires installation of a bracket before it can be used on that socket. Mounting socket plates on both coolers is basically the same."

    I was rather hoping there would be a bolt-thru plus backplate solution for socket 775, which would have avoided the main gripe with the Ninja, but it seems it's not to be.
  • Wesley Fink - Thursday, April 5, 2007 - link

    It seems that every cooler or hard drive review that we have recently posted is met with rocks from SilentPC "readers". This is really puzzling, since we have stated many times that we admire the good SPC has done in making manufacturers pay much more attention to the noise their components generate. There are many more choises of low-noise components because sites enthusiasts and sites like SPC have pointed out the noise offenders, and buyers have bought the quieter version instead.

    Testing component noise in isolation provides useful information, but AnandTech has a long tradition of "Real World" testing. Overclocking also has very different demands than building the quietest PC to run at stock speeds. The noise floor for any working system will be the power supply generally, and possibly the video card or ambient room noise. It doesn't matter in our approach how quiet a fan is if the power supply is 20db louder. This is pretty obvious but it is rarely mentioned when people are screaming about a fan at 14dbA versus a fan at 18dbA or power supplies that are 2db apart at 26db. Does it really matter if the power supply in the system is at 36dbA?

    We do plan to move to a quieter power supply in our test bed as soon as we can find one that meets our needs. We have looked at several of the power supplies proclaimed in comments in past reviews as "MUCH quieter than the OCZ PowerStream 520W". They were quieter at idle, but at load those power supplies were virtually the same noise level as the OCZ. Idle noise might matter if you sleep in the same room with your computer, but you can't do anything with an idling computer except look at it. We believe the normal operating noise measurements are the noise levels that matter most.

    If readers prefer the review approach of another site that is their right, but we do hope they will stop investing so much emotion in thier comments. We think there is room for both the component isolation approach and the AnandTech "real world" approach. We also don't think there is any "right" or universal truth to be gleaned here - they are just different approaches.

    We chose the SilenX fan because it specified higher output than the SFlex at noise levels that were far below our system noise floor. We could just as easily have used the SFlex with a specified 63.7cfm instead of the 72cfm of the SilenX. However, since we have not yet done our fan review we didn't want to tilt sentiment too strongly to one brand name so we chose another quality product to put another deserving brand in the spotlight.

    Our plan going forward is to complete a few more waiting cooler reviews, and then select the top air cooler from our reviews. This will be followed by a fan roundup testing fans on our top performing HSF. New reviews will then be tested with stock components PLUS the top fan from our roundup. This should provide some consistent answers to some valid real-world questions.

Log in

Don't have an account? Sign up now