HWLabs Nemesis 360 GTS X-Flow 360mm Radiator Review

1. Introduction2. Technical Specifications3. Flow Rate Testing4. Thermal Testing5. Data Analysis6. Summary7. View All

Introduction

HWLabs Nemesis 360 GTS X-Flow 360mm Radiator Review

Welcome to another Extreme Rigs radiator review. This time we’ll be taking a close look at the Nemesis 360 GTS X-Flow from HWLabs which was released back in 2014.

We reviewed the regular Nemesis 360 GTS for the Extreme Rigs Rad Round Up 2015, and we have also featured it’s data in some reviews which are the start of our Slims Only version of the Round Up, but we really wanted to see some comparisons between the “regular” Nemesis GTS and the X-Flow variant, and so the testing commenced.  The X-Flow variant is essentially the same core as the GTS but with input and output ports at the opposite ends of the radiator rather than at the same end.  This can help some builds simplify tube routing.

We’ll show the test results compared to another 5 slim 360mm rads which we have completed testing on, and the occasional comparison to the full suite of 29 360’s that we have tested.

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So before we delve in, a well-deserved Thank You to HWLabs for providing the review sample of the Nemesis 360 GTS X-Flow!

What’s in the Box?

The Nemesis 360 GTS X-Flow sample from HWLabs arrived in full retail packaging.

The front of the retail sleeve has the now standard Nemesis design and likewise on the back where we find some technical drawings and list of features.

Removing the outer sleeve we find a sturdy shipping box with a factory seal sticker that gives us a warning about using correct length screws.

Just to clarify: when using the supplied mounting hardware there is no risk of causing damage to the radiator.

We noted in our unboxing of the regular 360GTS that the inner box design has potential to cause damage to the radiator because of the flaps which were pressing down on the core.  The old box is shown below:

We are very pleased to see that the packaging has been redesigned since then and the potential cause for damage has been removed from the GTS X-Flow boxing (and other Nemesis models we’ve received recently):

I really like the HWLabs style of boxing as the compartment at one end keeps the provided accessories away from the core. It would be nice to see a bubble wrap sleeve over the rad, but otherwise the GTS X-Flow has great packaging that should ensure safe arrival to the end user.

Extent of Delivery:

• 1 x Nemesis 360 GTS X-Flow Radiator
• 12 x M4 x 28mm screw s for mounting fans.
• 12 x M4 x 5mm screws for attaching the radiator to the case.

Under the flap on the right hand side, we found 2 bags with the supplied mounting hardware:

Note that the 28mm screws are only just long enough to mount fans directly to the radiator. If using a mounting bracket, or placing fans between the chassis and rad, you will need to provide your own M4 screws of suitable length. In most instances M4 x 30 screws will be suitable.

Onwards to the technical specifications!

Technical Specifications

Technical Specifications as listed by HWLabs:

• 120 mm x 3 fan slim form factor one-pass radiator.
• 412mm x 133mm x 29.6mm (L x W x H)
• 16 FPI 25 Micron Copper Fins
• Now optimized for sub-800 rpm ultra-stealth fans
• Supercruise optimizations for scalable performance with higher speed fans
• 15% more tubing area in the same Black Ice® GTS™ 360 XFLOW form factor
• Increased internal coolant flow rates
• Standard G 1/4″ inlet/outlet fittings
• Standard M4 mounting threads
• Compatible with Black Ice® Pro III XFLOW, Black Ice® GTS™ 360 XFLOW radiators
• Custom Dark Matter™ high quality finish
• Fully ROHS Compliant
• 100% Made from conflict-free materials
• Industry standard Black Ice® quality
• Lifetime warranty against manufacturing defects*|

* Limited warranty information: www.hardwarelabs.com/nemesis/warranty

HWLabs do indeed supply some excellent technical data on their radiators via the internet. Let’s see if the retail sample matches what the promotional material promises the end user.

Dimensions Measured on the Radiator Tested:

Radiator Core Dimensions:

The data seems to match.  The core is made up of one layer of 14 tubes arranged in a single pass (end to end or X-Flow) configuration. Being the first X-Flow we have tested and having the non X-Flow version’s data already, we were keen to see just how much the flow rate and pressure differed in the restriction testing because the NON X-Flow was the second most restrictive rad we have recorded. More importantly, how much (if at all) would the thermal performance suffer? The core appears to be exactly the same on both models, with the end tanks and port locations being the only differences.

The split (or splitter) fins are non-louvered and are spaced quite unevenly between the tubes. With quite a high fin count we have come to expect this and it appears to be luck of the draw as to how well (or not) the fins are spaced.

In the following pics we can see fin counts of 15 and 18 FPI which is close enough to call 16 FPI as per HWLabs specs, but we would like to see some improvement with the fin spacing.

Finish and Features

The 360GTS X-Flow has a silky smooth matte black finish and while I readily admit to being a fan of the HWLabs black finish, this is the best example that I have looked over for quite a while.

All visible joints look good and care has been taken not to get paint inside the G ¼ threaded ports. The side panels are not at all flimsy and overall this rad feels and looks very solid.

The fan mount spacing is the standard 15mm. Also in this photo it is evident just how uneven some of the fin spacing is.

The fan mounting holes are not located directly above any tubes, but they are very close so HWLabs have still chosen to fit protection plates under each screw hole. It is this attention to detail and the inclusion of hidden extra features which make an excellent radiator stand out from the rest.

There are just 2 ports in total, one at each end of the radiator and either can be used for the inlet or outlet port.

The end tanks and ports are symmetrical with each end being an exact opposite of the other. The inherent nature of the design means that the X-Flow is a bit longer than a regular 360mm radiator, so make sure you have space to accommodate the extra length.

The tank design looks to be perfectly shaped for a vertical installation in both a length ways or sideways orientation as the angled tanks should greatly assist in initial bleeding of the radiator/loop.

As mentioned previously there are no extra ports on the 360GTS X-Flow. No alternate ports, no ancillary fill/bleeder port – nothing.

Maybe we have become too accustomed to multi ports in recent years and our loop planning now automatically assumes that all radiators will have them. While in a vertical installation the 360GTS X-Flow would be a breeze to bleed, a roof mount would be more difficult and could be avoided if there was at least one port on the opposite side to that which the ports which are fitted.

We would have preferred if one of the end tanks was “squared up” and fitted with a few extra ports which would add options for easy bleeding and draining.

So here we have a 30mm thick, 360mm radiator which has a X-Flow single pass core with a fin count of 16 FPI. The end tank design is good but it is lacking any alternate port options. The mate black finish is excellent as is the overall build quality.

Let’s see how it performs…

Flow Rate Testing

The Data

As all the testing in this round up was performed with the exact same equipment, using the exact same methods I have decided to keep each radiator’s pages uncluttered by posting our testing methodology, test set-ups and equipment used in a single location. To see exactly how the tests were carried out, details of the test set ups and equipment used, please head back to the RRU Test Setup page.

Restriction Test

It’s generally agreed that radiators are one of, if not the least restrictive components in the water cooling loop. There are some exceptions however, so this must still be verified through testing:

The above photo is for referencing the restriction test bench and the 360GTS X-Flow is not loaded so please disregard the data in the picture as it does not relate to the its test results.

Here is the raw data at the tested flow rates, displaying the measured Differential Pressure across the radiator as flow rate was increased.
The 360 GTS X-Flow appears to be a radiator of medium restriction, unlike the NON X-Flow variant which was one of the highest we have recorded. However numbers in isolation can only tell half the story. By plotting against other components it more easily shows the whole story.

We use a HeatKiller 3.0 CPU block as the reference in these plots for two reasons. Firstly there is no chance of the plot being cluttered by curves overlapping and secondly it gives a reference point against a fairly common loop component of average restriction. As with all the radiator restriction plots I have limited the maximum flow rate displayed to 2.0 GPM as I suspect there are very few systems that operate above 2.0 GPM. For more information on how to read a restriction plot check out our guide.

This plot indicates the 360GTS X-Flow as a low restriction loop component when compared to a CPU block of average restriction, but what about other radiators?

The next three plots show the restriction level relative to other slim radiators in the test group at 3 different flow rates. We consider the chosen GPM rates to represent systems which have low, medium and high flow rates.

From these plots it would be fair assessment to call the 360GTS X-Flow a low restriction radiator when compared to the other slims, but before we make that conclusion let’s take a quick look at the restriction levels of our 360 rads at 1.0 gpm.

So our low restriction assessment made previously when isolated against only the slim rads has not proven to be entirely accurate. When put into context with all the 360 rads, a medium restriction radiator it is!

Of special interest in the above plot is the regular 360GTS having a result of 0.91 DP PSI, while the X-Flow has just 0.36. Note that the above plot is for 1.0 GPM only and the DP PSI variance should increase as the flow rate gets higher.  Essentially then the XFlow is about 40% of the restriction of the non X-Flow.  This is higher than we might expect – the XFlow has the same amount of tubes but uses them differently.  The X-Flow has all tubes in parallel and they run only once along the radiator; the regular GTS uses half the tubes for one direction and half the tubes in the other direction.  In other words, the X-Flow coolant travels though a 2x wider pipe for half the distance.  Restriction should then be 25% of the regular GTS, however not all restriction comes from the tube – there will be some also from the end tanks and fittings.

Let’s take a look at the both together then:

At this stage we still weren’t entirely certain whether this restriction difference would have any impact on the thermal testing as we are setting constant flow rates.

Onwards to thermal performance to find out!

Thermal Testing

The Thermal Data

Moving on from the restriction test bench the HWLabs 360GTS X-Flow was loaded into the thermal test chamber for a series of 12 tests – consisting of 3 flow rates for Push/Pull and a single flow rate for Push Only, each having 3 different fan rpm speeds tested.

Below is the final data results gathered from at least 5 data logging runs at each flow rate and fan rpm combination. The most stable 15 minute period from each logging run was used and then averaged with the other runs to obtain the data for the table below. A total of 16 temperature sensors were used in the thermal test chamber (8 air in, 2 air out, 3 water in, 3 water out) each take a reading every second and logged via a CrystalFontz unit. The data in the table below is the averaged results of the logging runs which has then been used to create all the plots and tables there-after.

The performance metric of critical importance is the delta between the warm coolant temperature in and the cold ambient air temperature in to the radiator. Given that the system is well insulated and in equilibrium and we know the heat input to the system then we can also calculate a very important number – that is the amount of power required to raise the coolant temperature 1C (or 10C which is more useful reference point).

Let’s take a look at the Delta T results from the tests.

Note that the extrapolation of the curve in the plot format is much more sensitive to error than in between the tested range.

We’re not too concerned about the actual delta numbers here, more so if a trend pattern between fan speeds is occurring. It’s interesting to see the Push Only which is at 1.0 gpm draw closer to the 0.5 gpm Push/Pull as the fan speeds increase.

Delta T results (as above) is not always helpful when thinking about how many radiators you would need to cool your system. Instead it’s more useful to know the delta/W, or more usefully, the inverse metric of W/delta C. The metric plotted below tells us how many watts are dissipated by the radiator when the coolant rises 10C above ambient temperatures. (W/10 Delta T):

As expected increasing airflow through the radiator is the primary determinant in changing the radiators performance. The lack of variance between flow rates indicates the GTS X-Flow is very well tuned for low flow rates and any increase is not adding much performance benefit whatsoever.

The same data can now be plotted as a curve so that an end user can interpolate their own fan speed. Note that the extrapolation of the curve is much more sensitive to error than in between the tested range.

Let’s exclude the push data for now and come back to it:

The tightly bunched lines are evidence that increasing flow rate is yielding little benefit in performance. With each flow rate curve flattening out at the high fan speeds we conclude that 400 Watts is about the limit of heat dissipation while maintaining a 10°C Delta. With 6 six fans at 2400 rpm this would be excessively loud and would actually have worse performance than A Push Only set-up as seen in the next plot. Therefore we think the sweet spot for Push/Pull is around 1300rpm for a 300Watt dissipation level.

If we now come back to the Push Only data it’s good to compare the Push to Push/Pull data in an “apples to apples” fashion by only looking at the 1GPM data:

Push only gives around 87% (averaged) of the performance of the Push/Pull 1.0 gpm test results on this radiator. That average may not be a good representation of the comparisons however as we recorded a difference of 78% at 750 rpm and as fan speeds increased the comparison drew closer together: 90% at 1300rpm and 94% at 1850rpm. The trend line indicates the Push Only would have beaten Push/Pull at around 2100rpm -however this is most likely just because our extrapolated lines have some inaccuracies when you go beyond the range tested.  There is no reason for push/pull to ever perform worse than push – at some airflow they will essentially become the same and “max out”.

In this next plot all three Push/Pull results at each flow rate were averaged to produce one curve and we compared the results against the best and worst performing of all the 360 rads we have tested.. Averaging reduces test error of course so this helps further to be sure of our data and is more useful therefore for comparing to other radiators.

To give some perspective, The EK XE 360 is twice as thick as the GTS X-Flow (and the EK SE) and was a performance beast which placed first in nearly every thermal test we conducted on it. The comparison radiators were chosen as they are the current best and worst performers of our entire 360mm test group.

Perhaps it is fairer to compare the GTS X-Flow only against other slim radiators.
Firstly the Push Only Slims at 1.0 GPM
In Push Only, which we believe is the most likely installation scenario for a slim rad, the performance of the GTS X-Flow was weaker than the regular version of the GTS at all our test data points.

And the Push/Pull Slim rad comparisons:
We clearly see one rad which is weaker than the rest, and one which is better at high rpm in Push/Pull. The fact that the GTS X-Flow is so competitive is fantastic as it means you can have the benefits of a X-Flow radiator design with easier/cleaner tubing runs without any significant loss of performance.

Now let’s analyze that data some more…

Data Analysis

This first table shows the Nemesis 360 GTS X-Flow’s Watts/10 Delta Temp numbers in a quick glance chart format.

Using the data compiled from the thermal testing I have compiled the following tables in an attempt to show other ways of how the GTS X-Flow’s performance varies against itself at the flow rates and fan speeds tested. Effectively these show percentage gains relative to a reference point. It’s an interesting way to show gains/losses while changing a variable.

First let’s focus on 1300 RPM as our reference and see how much gain or loss in performance we get by changing fan speed.

Rather even percentage differences here indicate the tuning of this rad is well balanced. The exception here is the Push Only 750 RPM which we actually did a Re-test on because the data stood out as an anomaly from the initial testing. Re-Tesing produced a result which was very similar to the first tests.

Let’s now focus on the Push/Pull data looking first at the changes from 1.0 GPM:

With only slight percentage changes when changing the flow rate we conclude that flow rate is not a determining factor for performance on the GTS X-Flow.

How about we combine both flow rate and fan speed as reference points and have a look at 0.5 GPM & 750 RPM as the reference point.

Lastly, we change the reference and choose the center 1300 RPM and 1.0 GPM as our reference point to show both effects concurrently:

So from the data above we can get a very good idea of how the 360 GTS X-Flow radiator performs relative to itself. But there is a large selection of 360mm radiator models to choose from, released from numerous manufacturers. So, we need to start comparing performance between them.

Push Only Data vs Competition

Let’s focus on the Push Only results for now and come back to the Push/Pull data later. While for Push/Pull we tested three flow rates, the Push Only testing was conducted only at 1GPM in order to save time. For a comparison vs. thicker radiators make sure to check out the Extreme Rigs Rad Round Up.

Let’s start with 750 RPM and see how it compares to the Slim Rad competition:

The GTS X-Flow performed poorly in the low speed Push Only rankings having performance a hefty 16% behind the winner, its sibling, the non X-Flow version of the same rad. After Re-testing and getting the same result, I am at a loss to explain why only this data point performed as it did. There is no pattern that it falls into and makes it difficult to understand why it is so!

How does the GTS X-Flow do at 1300 rpm?

At 1300 RPM Push Only the gap closing to around 9% behind the winner.

At 1850 Push Only the GTS X-Flow has gained more ground on its non X-Flow sibling, but the Koolance rad with a super dense 30 FPI core has jumped ahead to take 1st place.

So there was an expected and unexplained weak result in Push Only test with low fan speeds, but the performance was decent at medium and high fan speeds

Let’s find out how the GTS X-Flow compared in Push/Pull:

Push/Pull Data vs. Competition

For Push/Pull we have averaged the results from the 3 flow rates at which we tested.

First up the 750rpm:

While the Push Only was rather weak, the Push/Pull result was exceptional, placing equal first with the non X-Flow variant of the 360 GTS and is ~6.5% ahead of the nearest competitor.

Let’s move to 1300 rpm:

At 1300 the GTS X-Flow takes a drop in the rankings and is ~5% behind the non X-Flow version while the denser core Koolance takes the lead.

Now 1850RPM:

At 1850 Push/Pull the results are similar to those of the 1300rpm.

So the 360 GTS X-Flow had one excellent result, one weak result and was average in the other 4.

Let’s combine the Push Only and Push/Pull results at our 1.0 GPM flow rate into one plot for each fan speed tested.

Again the 750 rpm first:

At 750 rpm we see the GTS X-Flow’s best and worst result on the same plot!

At 1300 and 1850 rpm everything looks in order given the data we’ve already reviewed.

From all of test results we created “Average Performance Factor” charts for both Push Only and Push/Pull and then a combined plot called the “Master Performance Factor”. The radiator with the best cooling ability (W/10ΔT) at each gpm/rpm combo was awarded a score of 100, and each other radiators W/10ΔT result was scored as percentage of the top performer.

This way of looking at the comparison takes away any advantages that a radiator may have at higher or lower fan speeds and looks at an overall average. While this appears fair it does tend to favor those radiators that are all-rounders and those radiators which do very well at high RPM. Most users should be more focused on their specific use case. Check in the Round Up for performance comparisons at every gpm/rpm combo for even more details and cross comparison results.

Here is the Nemesis 360 GTS X-Flow’s Push/Pull percentage scores at each data point that thermal tests were conducted at and additionally the 1.0 gpm Push Only percentages relative to the winner at each fan speed.

This show the excellent results of the GTS X-Flow in Push/Pull at low fan speeds (comparative to the other slims), in addition to the very weak result for the same fan speed in Push Only.

The percentage numbers in the table offer another way of looking at the GTS X-Flow’s results comparatively and how it performed, but for our scoring system we need a way to reduce the categories while retaining the data. To do this we average the results for each fan assembly type giving us Averaged Performance Factors for Push Only, Push/Pull and finally an average of everything in the Master Averaged Performance Factor.

Firstly – the Push Only APF:

The very weak low fan speed result really dragged down its average. We can see a clear winner and loser with the other 5 rads being tightly bunched within ~3% of each other.

Let’s also take a look at how the Nemesis 360 GTS X-Flow compared in Push Only against all the 360mm radiators we have tested.

Now the Push/Pull APF:

The excellent results in Push/Pull with low speed fans boosted the GTS X-Flow’s average and it placed in 3rd position, ~5% behind the top spot and only 3% behind the regular GTS.

Finally we created the Master Performance Factor which is calculated from the averaged results of all the thermal tests, Push and Push/Pull at all flow rates and all fan speeds.

In the Slims Only Master Performance Factor comparisons the Nemesis 360 GTS X-Flow finishes in fourth place. While the non X-Flow version obviously has the better overall averaged thermal performance it is clear that the altered flow pattern and reduced pressure of the X-Flow tube configuration has not significantly impacted on the thermal performance. I would speculate that many users would gladly choose the lower restriction at the cost of slightly lower thermal performance between the two models.

The all encompassing 360mm Radiator MPF!

Next up – Summary!

Summary

Thermal Performance

Thermal Performance scores are derived from the relevant Performance Factor scores. We set this scale with 72.5% and below as the 0 mark, with each 2.5% increase from 72.5% in relative performance adding 0.5 to the awarded performance score.

The Bold Scores are based on performance comparisons of only the slim 360mm Rads. On the second line is the score which is generated against all the 360mm rads from the complete round up.

Push Only Thermal Performance

• 3.0/5 – Slim Only 360mm radiators
  
• 1.5/5 – all 360mm radiators

The Nemesis 360 GTS X-Flow’s Push Only thermal performance was weaker with low fan speeds, and average at best with medium and high speed fans against the other slim rads.

Push/Pull Thermal Performance

• 3.5/5 – Slims Only 360mm radiators
  
• 2.0/5 – all 360mm radiators.

In the Push/Pull comparisons GTS X-Flow performed best (comparatively) with low speed fans and dropped off as the fan speeds were increased.

Overall Thermal Performance

• 3.5/5 – Slims Only 360mm rads.
  
• 2.0/5 – all 360mm rads.

With the exception of one data point (which was re-tested to verify the result) the 360 GTS X-Flow had extremely even results for each rpm rate at all flow rates. This resulted in a good averaged result for the X-Flow version of the GTS and ended up in fourth place overall ~ 6% behind the winning radiators score.

Features & Quality – 4.0/5

The Nemesis 360 GTS X-Flow from HWLabs has an excellent matte black finish. Construction quality is fantastic and has a solid and weighty feel to it and the inclusion of tube protection plates is always a welcome feature.

The end tanks have a unique angled shape which should greatly assist in bleeding air from the loop in a vertical installation. With just 2 ports and no ancillary port either, we feel a little bit deprived after having just finished reviewing the SR2 MP which has 8 ports.

As the name suggests, X-Flow is the key feature of this radiator. The X-Flow coolant flow path means that tubing runs of the loop can be done with much less clutter and may even provide opportunities for hidden tubing depending on the case being used. The X-Flow design does generally mean a performance loss but HWLabs have done a great job with the tuning to keep the performance hit to a minimum.

While being a thin rad at just 30mm thick, the X-Flow end tank and port design does mean the overall length of 411mm is longer than virtually all other 360mm radiators.

Summary – 3.5/5 – Silver Award

The HWLabs Nemesis 360 GTS X-Flow is a slim radiator, which by default means it will never have outstanding thermal performance. When we break down the results and look at the thermal performance of only the slim rads, the GTS X-Flow was an average performer and placed 4th in the overall rankings.

Being super slim it will fit in most places locations that have 3 x 120mm fans spaces side by side, but the extended X-Flow tank at one end does make it slightly longer than other 360mm rads.

The build quality and finish are excellent and the X-Flow design almost makes up to the lack of any alternative ports, additionally the X-Flow design has significantly lowered the restriction level compared to that of the regular 360GTS.

HWLabs have offered the market another option with the Nemesis 360 GTS X-Flow. While it is unlikely to ever be hugely popular, it definitely has its place for those who like to keep tubing to a minimum while managing to retain respectable performance for a 30mm thick radiator.

Overall the Nemesis 360 GTS X-Flow is an excellent slim radiator. While it’s not perfect it would still be our first choice for any build where space constraints meant that a slim rad must be used and this is why it earns a Silver Award.

Where to buy:  Performance PCs – $66.95