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Test Report: XSPC RX120

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WB, pump & rad molester
Jul 1, 2007
Minneapolis, MN
8 FPI Radiator

I would like to thank Paul at XSPC for providing a pre-production sample of the new XSPC RX120 Radiator for testing purposes. Paul is a great guy, extremely knowledgeable, very quick with communication and truly listens to feedback. I had never had any experience with XSPC other than the DDC pump tops, but the experience I have had through the testing process on the RX Radiator series has made XSPC a company I would work with anytime and one that I would gladly give my business to.

For the full review, please visit skinnee labs


The XSPC RX 120 is part of a brand new line of radiators from XSPC, the RX line includes a 120 (Single), 240 (Double) and 360 (Triple). This new addition to the XSPC product line is another great product in an extensive line of enthusiast liquid cooling products. XSPC is known for making great products and extremely competitive prices. After my experience with the RX radiators, I am eager to try other XSPC products, well, besides the DDC Res Top that I have running on the test bench CPU loop.


This review and test report will focus on thermal testing. Pressure drop and flow testing will be added in a week or two. So without further delay, lets get on to the review and testing shall we.

Radiator Characteristics

The RX line is very different from the previous RS series from XSPC, starting with the tubes. The tubes and fins on the RX series are all copper. Previously, the RS series used brass tubes. Upon first glance of the radiator you notice the fin spacing, the RX series features 8 Fins Per Inch (FPI), which is one of the lowest FPI's in used for liquid cooling radiators. The next thing I noticed once I got over the different look of 8FPI was the size of the RX120, this radiator is definitely thicker than the RS line. The RX120 measures in at 162mm in height, 125mm wide and 58.5mm thick. One more thing on the topic of fins, the more I looked at the fins, something else seemed different. I tried capturing this in a photo but could not get the photo quality to really show what I saw ( I will keep trying though), the fins are split between the tubes. I have never noticed if this is the same on other radiators optimized for low speed fans. I will have to look closer next time I have a low speed fan optimized radiator in my hands.

XSPC followed the industry standard and used G1/4 barb ports, which allows users their choice in fittings, no special adapters needed for the common and popular fittings in use today. The sample RX120 I have is a pre-production sample, but the paint job is very good and I couldn't believe this was pre-production paint. Fan mounts are pre-tapped for M4, I ended up using 6-32 screws for my testing which worked just fine in the pre-tap M4 holes.

  • Black Gloss Finish
  • Copper Tubes
  • Copper Fins
  • G1/4 Barb ports
  • 8 Fins Per Inch (FPI)
  • M4 tapped screw holes
  • (H x W x D) 162mm x 125mm x 58.5mm



Pressure and Flow Results

Unfortunately I did not have a working manometer at the time of testing to perform Pressure Drop testing on the RX120. I am once again armed with a working and much better manometer (specifically made for liquids) as I write this, so pressure drop testing will be added during the testing of the RX360. Sorry for the inconvenience.

Thermal Testing Methodology/Specification


I chose to follow the standard methodology and procedures that Martin used time and time again in his excellent tests, that coupled with all of the mentoring he has provided his methods are the most logical and scientific out there. Not using Martin's methodology and procedures would be reinventing the wheel and ultimately result in confusing test reports for everyone to read.

For radiator testing, the best way to conduct the tests is to apply a heat load, just like your CPU, GPU(s) and other components you can put a block on and add to your loop. In order to supply the heat load for testing, I use a modified aquarium heater. Aquarium heaters are available in a variety of different wattages, lucky for us wattage is exactly what we are looking for in heat dissipation results. However, the tricky part with aquarium heaters is circumventing the safety mechanism that shuts off the heater when the set temperature is reached. Modifying the aquarium heater allows for a constant heat load to be applied to the loop rather than heating the water to a given temperature and shutting off.

Measurements and calculations, what exactly are we going for here? One of the best means to determine the capabilities of a radiator is C/W, Martin turned me on to this in one of his early tests. Ultimately, C/W is a calculation of Water Out temperature minus the Air Temperature being pulled or pushed through the radiator divided by the heat load (wattage). This calculation gives you the delta in degrees of the radiator leaving water for each watt of heat applied to the radiator. Confused yet? An easier way to think of C/W is the temperature of the water over ambient temperature for each watt of heat in your loop. Now that we have this equation and results we can specify a set delta and figure out what heat load the radiator can dissipate at that specified delta. In short, this helps answer the question, can this radiator handle a CPU and GPU and get me decent temps. A bit more on C/W, this time in relation to Fan RPM. On several charts later in the test report you will see Fan RPM charted with C/W. This is to show the effect on radiator performance in using different speed fans, some radiators perform very well using low speed/cfm fans and get better the more cfm you push/pull through the radiator. Where some radiators perform sub-par with low speed/cfm fans and require high speed/cfm fans to effectively dissipate heat from your loop. Yes this has a lot to do with how the radiator was design, but I feel it is an important piece of data to show as a misconception I had early on in the start of my liquid cooling addiction was low speed/cfm fans could not be used on radiators optimized for high speed/cfm fans. I was quickly shown how wrong my thinking was.

Test Note: For this round of testing I am using a heat load (300w) that is roughly double the typical heat dissipation capabilities of a single 120mm radiator. However, the calculations are still accurate.

Due to the fact that I do not presently have a 150w aquarium heater for testing and cannot run tests using two different heat loads, I wanted to be sure my numbers are accurate, so each of the tests were run twice to verify the accuracy of collected data. The actual Air Out and Water Out temperatures will be much higher than normal giving the Test Note above concerning heat load used for testing, but again the calculations are what we are going for.


A total of 5 tests per round were completed with a total of 2 rounds, each one of the tests used a different Fan RPM to represent different fan scenarios. This gives a best coverage of uses of the radiator out in the wild, not everyone will want to use the same fans or run their fans at a specific RPM, so I tried to cover 5 different RPM settings. Each test consisted of a 30 minute warm-up period with the heat load applied to the loop and a 60 minute logged test run. The heat load was applied by adding the modified aquarium heater in a custom built half-gallon reservoir. Below is list of all of the tools.

  • Temperature Monitoring and Logging: CrystalFontz CFA-635 with SCAB attachment - Used to log 7 temperatures (4 air, 3 water) and one Fan RPM sensor at 5 second intervals.
  • Thermal Sensors: Dallas DS18B20 Digital one-wire sensors - .5C absolute accuracy overall with a .2C mean error between 20-30C.
  • Test Bench Sensors Deployed:
    • 2 air in sensors per fan
    • 2 air out sensors per fan
    • 2 water out sensors
    • 1 water in sensor
  • Flow Rate: King Instruments 7520 0-5GPM, 10" Scale - Accuracy 2% of scale. Flow Rate controlled by a brass gate valve with 1/2" NPT 5/8" Barbs
  • Water: Local Grocery store steam distilled water
  • Fans:
    • Yate Loon D12SH-12 120mm x 25mm - 88CFM/2200RPM/40dB
      • Ultra Slow Speed Fans - Undervolted to 1000 RPM
      • Slow Speed Fans - Undervolted to 1400 RPM
      • Medium Speed Fans - Undervolted to 1800 RPM
    • Scythe Ultra Kaze DFS123812H 120mm x 38mm - 133CFM/3000RPM/46dB
      • High Speed Fans - Undervolted to 2300 RPM
      • Ultra High Speed Fans - Volt Adjusted to 2800 RPM
  • Data Logging: Each temperature sensor and fan RPM channel is logged for 60 minutes after the 30 minute warm-up period. Having two sensors in one location (ie: water out) allows me to average the sensors together to rule out fluctuations. This also helps to ensure the system has stabilized and remained constant during the test.
    • Air Inlet Temperature Data: Each test uses two air inlet sensors per fan logged every 5 seconds for the duration of the test. The air inlet data is averaged using 1440 data points per test.
    • Water Outlet Temperature Data: Each test uses two water outlet sensors per fan logged every 5 seconds for the duration of the test. The water outlet data is averaged using 1440 data points per test.
    • Fan RPM: Fan RPM is monitored via the Crystal Fontz CFA-635 and logged at the same interval as all temperature sensors. The Power is adjusted via the CrystalFontz to an RPM setting and logged very 5 seconds during the test period.
    • Heat Load: Wattage for the aquarium heaters are measured via a KILL-A-WATT every 10 minutes during the test, I'm quite lucky to have stable power as this does not seem to fluctuate much at all. The aquarium heater wattage is added to the pump wattage (volts x amps) measured by a Fluke 23 Series II Digital Multimeter with power and additional monitoring from a Mastech HY3005D Variable DC Power Supply. These two inputs give us the total heat load applied, then averaged for the test duration.
  • Test Lab Environment: Unfortunately, I do not have an environment test chamber. All tests are performed in 10x13 room in my basement which is temperature controlled via a wall thermostat and on a separate zone from the rest of the house. I am able to maintain a consistent room temperature this way. For the test fixture, I am using about 4' of 1/2" ID 3/4" OD Masterkleer tubing (un insulated). The loop consists of a custom 1/2 gallon reservoir, Swiftech MCP655 (stock top), King Instruments flow meter (5/8" fittings) and a 3/4" brass gate valve (5/8" fittings).

Thermal Test Results

Applied Heat Load

Now that we have all of the methodology, specification and data explanation documented and detailed lets get on with what you all are looking for...the results.

Here is the main chart for bringing all of the logged data in and using this data to calculate Water Out-Air In, and C/W. Another column you see in the table is Air Capacity Used, this column shows the rise in air temperature relative to the water temperature.


Moving to the chart which helps potential users of the RX radiator, this chart plots the Water Out-Air In Temperature or Delta versus the Heat Load applied. This chart is the most useful in estimating the Delta for a given heat load (watts) to be applied to the radiator. Simply locate the wattage on the X axis and move up to find the Delta for a given fan speed. Add this delta to your ambient temperature, and that is what you can expect for a loop water temperature.


For information on calculating heat load for your loop here are two resources I have used in the past. Once again thanks to Martin for sharing these through his testing. Another method I have used in the past is to Google search TDP for a specific component, that should also help in estimating the heat load that will be in the loop for a specific component.

Please remember, calculating the power consumption and using that as heat load is not exact and is only an estimate. This estimate will be higher than actual heat load applied as you do transfer some heat to the air circulating in your case around the components. How much difference I cannot begin to speculate, but I just want to state that it is only an estimate and not an exact specification.

Applied C/W

Now that we have looked at the plotted results, lets apply the C/W results with a given Delta (Water Out-Air In) to find how much wattage can the radiator dissipate. Below is the data table for calculations of Deltas of 15º, 10º, 5º and 2º. Here is my classifications for those deltas.
  • 15º Delta: Low Performance, an overloaded but capable loop.
  • 10º Delta: Average Performance, very capable of good temps and representative of an average system.
  • 5º Delta: High Performance, for those of you looking to achieve the best possible temps.
  • 2º Delta: Uber Performance. extreme setups only and I really wanted to use the word "uber" somewhere in the review.


Here are the plotted C/W results over the fan RPM range, as you can see the results do follow close to a plotted trendline. This trendline might not mean much to you, but to me the trend line helps me see that my testing and resultant data are accurate. Additionally, if you plan on running your fans at a speed other than the ones I tested here is another reference point to estimate the results you will see.


This chart is just the plotted results for a 10º Delta or Average Performance from the data table in the beginning of this section. Given these numbers, even at 1000 RPM you could use the radiator for CPU cooling and expect good temps. Considering a Yorkfield TDP is specified at 95w. Take into consideration your overclock and I am sure you are still well within range to add a North Bridge block and have good temps.


Here are the plotted results for a 5º Delta or High Performance from the data table in the beginning of this section. Looking at the High Performance numbers, the RX120 would make an amazing Chipset and Mosfet loop radiator and take up only a single 120mm fan opening. Now all you have to figure out is where to put that pump.


Performance Comparison

Before going into this section, I need to thank Martin for the TFC Single 120mm and XSPC RS120 data. Without his testing and data this comparison would not be possible. As hard as it is to believe, I did not have any other single 120mm radiators in my resource pool.

This is the portion of the review where we stack the product up against others in the same product class. Looking at the chart we see the RX line outperforms the TFC 120 by roughly 12% at a 1000 RPM fan speed. The 8FPI design is truly optimized for low speed fans and is a true performer. If silence or quiet fans is your goal, the XSPC RX series is the clear winner. The RX performance margin only grows at lower fan speeds. As we increase fan speed up to the Medium range (1550-1800) the performance gap narrows to dead heat. The TFC 120mm starts to overtake the RX in heat dissipation above 2000 RPM, by less than 5% which is very small margin. That small margin stays consistent up to the top of our test range near 3000 RPM.


Price Comparison

For those of you looking to purchase a Single 120mm here are some prices of the RX and other comparable radiators. Prices were taken on 01/10/2009.
As you can see, the XSPC RX120 is $30 less than the TFC 120 and performs better with low speed fans and nearly identical with high speed fans. This is a tremendous price/ performance product.


As I stated in the beginning of this review and test report, the only experience I had with XSPC products was the DCC Res Top, but after the testing of this product I am eager to get my hands on other XSPC products. Traditionally, XSPC prices their products at very competitive prices and they never skimp on performance at the price point. Paul from XSPC is a great guy to deal with and very open to feedback. I have to assume that Paul has been listening to Liquid Cooling community after testing this radiator.

  • Standard G1/4 barb ports
  • Pre-tapped fan holes
  • Paint and Finish
  • Amazing performance at low fan speeds
  • Price

  • None that I experienced through testing

Overall, the XSPC RX120 is an amazing radiator. Everything about the radiator is exactly what the Liquid Cooling community is looking for. In my opinion, we have a new price to performance king as well as king of low to medium speed fans.


Apr 27, 2004
That's not bad for a single 120mm rad...that would cool any C2D I believe.


Nov 1, 2001
New Iberia, LA
Thank you for dropping in and posting your mini review, skinnee. And I want to personally thank you for picking up from where martin left off after he decided to quit testing water cooling components. :thup:


Apr 1, 2008
Mechanicsburg PA
Wow, that had to take a lot of time and effort on your part. Thanks for report. Looks lile we could have a new "TOP DOG" bang for the buck.

Keep it up.


WB, pump & rad molester
Jul 1, 2007
Minneapolis, MN
Thanks for the kinds words!

I've been a lurker here for some time, I always read but never posted. Figured it was time I started giving back for all the reading I have done here.

I will have a review and performance comparison of the XSPC RX360 coming soon as well. That review will include comparisons to the MCR320 and PA120.3.

Thanks for taking the time to read my review and for posting your comments and feedback. Without you giving me feedback I cannot improve the tests and presentation of the data. I am trying to pick up where Martin left off, but those are giant shoes to fill.


Apr 27, 2004
So your going to compare this to a MCR320 as well? I ask because I'm wanting to WC a VERY small case...and with the ability to dump out nearly 300w of heat...this could almost do a CPU & GPU.

atomic ferret

Nov 5, 2005
Nice to see you over here at OC, skinnee. Thanks for the review and putting in the time to conduct it. It looks like the new XSPC rads will give Thermochill and Feser a run for their money.


WB, pump & rad molester
Jul 1, 2007
Minneapolis, MN
So your going to compare this to a MCR320 as well? I ask because I'm wanting to WC a VERY small case...and with the ability to dump out nearly 300w of heat...this could almost do a CPU & GPU.

Correct, the RX360 review will also include comparisons to the MCR320 and PA120.3