120mm or 140mm case fans for my build? [UPDATE] Temp Test with both

[Alpha0mega]

I recently built a new system in the NZXT Phantom 530 case. Currently I am running just the default fans it came with, a 200mm front intake and 140mm rear exhaust. I have only added a Corsair AF140, suspended between the HDD cage at the bottom of the case and the optical drive bays, to blow air between my SLI 970s, which are two slot spaces apart.


Now that I have spent some time with my system, I am looking to add another couple of fans. One on the top of the case for exhaust (since I have felt the rear of the top mesh getting warm), and one on the bottom of the case for intake.

The bottom can only take 120mm fans, and has a dust filter. The top can take 200mm, 140mm or 120mm. So I am planning on putting one 120mm Corsair SP120 LED (because the filter will need static pressure) at the bottom, and was planning on putting either a Corsair AF140 or a SP140 at the top, but looking at the stats has me a little confused.

Based on these stats, why would anyone choose the 140mm fan over the 120mm? The latter has higher airflow, higher static pressure, lower noise, and is cheaper to boot. Is it only for those mounting points that can only take 140mm fans? Is there any advantage on choosing the SP140 for the top, or should I just put one 120mm intake below and the same model on top as exhaust?

Another possibility is that I put one SP120 below, remove the existing SP140 from cooling the graphics and move it to the top exhaust position, while the second SP120 gets used for cooling the GPUs. Would that be better for GPU cooling? The AF140 specs are:

Photo of my current setup (the AF140 is between the bottom HDD cage and the optical bay):

The SP120’s airflow isn’t too much lower, but its static pressure is far higher. And while there isn’t any direct obstruction to the AF140’s intake and exhaust (it’s suspended), there is still going to be some breakup of the air flow by the cards themselves. Would the higher static pressure of the SP120 help push the hot air exhausted by the cards out of the case (note that the PCIe slot guards in the Phantom 530 have slits in them)?


So, my questions are:
1) Any point to the SP140 over the SP120 fans?
2) If the AF140 better suited for the GPU cooling job over the SP120, or should I put a SP120 there and move the AF140 to the top?

Any other suggestions are most welcome.


PC Specs, if needed: i7 5820k 4.0GHz @ 1.09v, Noctua NH-D15, MSI X99S SLI, G.Skill DDR4 16GB 2400MHz, Zotac GTX 970 SLI, OCZ Vertex 2 SSD + WD Black 1GB, SeaSonic S12-D 850W, Phantom 530

[UPDATE]
So I got the SP120 LED fans and tested them against the AF140 is different configurations, posted further on in this thread. The post is fairly big, so here is the link:
http://forums.anandtech.com/showpost.php?p=37132897&postcount=35

 

[ClockHound]

You might want to look at the silentpcreview test results for those fans.

Then get both or neither. The SP120 is designed for rads, not a general case fan - as you'll see in that review. The AF140 Quiet is better than either 120s as a case fan, imo - better flow and quieter. I'd consider looking at other brands as well, unless you're getting the Corsairs for super cheap.

It might be interesting or useless to attempt to channel air from a bottom-mounted fan towards the GPUs using only duct tape and some plastic signboard. Then with a Sharpie, draw bendy arrows on the signboard to notify the air molecules of the ideal trajectory. That step is optional, as most air molecules just seem to follow the stream and don't stop to ask directions.

And keep your existing fan in place. Maybe install a quiet 120 in the front either above the drives or below them.

I'm not a fan of top exhausts - but I love puns - especially with your Noctua shooting out the back.

Expect the B-Duck to jump in here and tell you how to drop CPU temps and save on car insurance by ducting your cooler to the exhaust. His results are pretty impressive, except for the insurance part.

The whole fun, at least I think it's fun, is to experiment. Yes, that means you may have some fans leftover, but these days with the pressure of social media, who doesn't want extra fans?

More links: SilentPC 140mm Part 1 - spoiler alert:

Spoiler

They like the Phanteks PH-F140HP/TS best

. As do I.

Older SilentPC 120mm comparo. They liked the

Spoiler

Corsair AF120 Quiet - not 1st place tho

.

 

[Essence_of_War]

Based on these stats, why would anyone choose the 140mm fan over the 120mm? The latter has higher airflow, higher static pressure, lower noise, and is cheaper to boot. Is it only for those mounting points that can only take 140mm fans? Is there any advantage on choosing the SP140 for the top, or should I just put one 120mm intake below and the same model on top as exhaust?

Fan ratings are complicated. In general, fans have a P-Q curve that rates their airflow vs. static pressure, and for the ratings they just pick off the max airflow @ 0 static pressure, and the max pressure @ 0 airflow. So there is an entire function connecting those end points that you don't know about from the ratings. But even the P-Q curve doesn't really tell you the whole story, because obstructions like a radiator, a hard disk cage, or a heatsink don't come with a "rated static pressure". The only really useful way to evaluate the fans is to test them under controlled conditions.

ClockHound gave you some excellent links. I'll call attention to the Antec TwoCool 140, which is inexpensive, performs well at all voltages, sounds great at stock, and gets even nicer acoustics with a bit of undervolting. I have personal experience with the AF 140 QE as an exhaust fan. I didn't take any quantitative measurements, but the qualitative "feel the air coming out the exhaust" felt dramatically different and I can't hear it until I put my ear really close to it.

 

[BonzaiDuck]

Fan ratings are complicated. In general, fans have a P-Q curve that rates their airflow vs. static pressure, and for the ratings they just pick off the max airflow @ 0 static pressure, and the max pressure @ 0 airflow. So there is an entire function connecting those end points that you don't know about from the ratings. But even the P-Q curve doesn't really tell you the whole story, because obstructions like a radiator, a hard disk cage, or a heatsink don't come with a "rated static pressure". The only really useful way to evaluate the fans is to test them under controlled conditions.

ClockHound gave you some excellent links. I'll call attention to the Antec TwoCool 140, which is inexpensive, performs well at all voltages, sounds great at stock, and gets even nicer acoustics with a bit of undervolting. I have personal experience with the AF 140 QE as an exhaust fan. I didn't take any quantitative measurements, but the qualitative "feel the air coming out the exhaust" felt dramatically different and I can't hear it until I put my ear really close to it.

"He has enlarged my mind!" [Joseph Conrad/Ted Turner]

Most helpful short analysis. Thanks.

There are two types of "ratings:" the manufacturer's, in dBA, CFM, RPM, and static-pressure. Then there are tests by independent parties and reviews.

I wrote a thread on the GT AP-30 -- I think "116" or "117 CFM" were in my title line. The fan was rated at ~117 CFM by the manufacturer. Another established tester-reviewer (Martin's . . . Liquid something-or-other) performed the photo-documented lab test, assessing the actual CFM at [ . . get this -- hold on to your hats and socks . ] 144 CFM.

It could work either way, but for some specs like RPM there may be a 10% tolerance range either side of the mean. For fans this may mean more fans can fall short -- it would only make sense.

I start with basic web-searches for certain sizes and pin-outs. I'll get PWM where I want them, and settle for 3-pin for certain deployments. Then there are forum references to the same fan-model. You can look at the manufacturer spec pages. With luck -- you find a tech-review. But the more you pursue any "second opinion," the more time and trouble.

I find 140's of 100 CFM or more in the spec can be useful, and better if they are PWM fans. I sort of sneer at fans rated at less than 80 CFM, but I use them. Here and there, anyway. Cougar Vortex makes a decent one with noise-isolated corners. I tried to "get away" from 120mm fans, but I've found they can be extremely useful for some things -- maybe quite a few things.

 

[Alpha0mega]

@ClockHound, Essence of War - I do like the AF140 QE that I have (blowing on the cards), but I can only put a 120mm fan on the bottom. I want to put a fan there to pull cool air from outside, throw it upwards, where some of it will be pushed by the AF140 towards the cards, as well as getting some to the rightmost Noctua fan.

Keep in mind that there is a dust filter on the bottom, which is quite dense:

Will not a low-static pressure fan be choked by it? Been reading around, and people recommend SP fans where filters are concerned, similar to where radiators are concerned. Corsair itself mentions that "AF case fans perform best in unrestricted spaces with at least 3 cm (1.2&#8221 of clearance" and also where there is "unrestricted intake". (www.corsair.com/en-in/air-series-af140-quiet-edition-high-airflow-140mm-fan)

The reason I want a top exhaust is that, if I put my hand on the case mesh near the back, there is quite a big temperature delta between that location and the middle/front of the mesh. I had assumed that the rear exhaust would be enough, given the Noctua fans are blowing in that direction, but since the back area is getting warm, I want to put a fan there to move the hot air out of the case faster.

I had seen P-Q Curve data on the older SP120s (non-LED), but couldn't find the same on the newer LED ones. I personally don't want LED lights, and will be removing them, but the older SPs are either too loud (PE), or too weak (QE).

I tried to "get away" from 120mm fans

Why? The normal reasons for going 140 over 120 are a (slightly) greater area of air flow, and that they are supposed to push more air at lower RPM, resulting in less noise. However, if the 120s are better in every rating, by the same manufacturer no less, like the SP120 is over the SP140, what would be the reason to pick the 140, apart from perhaps the fan mount point not being able to accommodate a 120 for some reason.

The rated specs of the fans are relevant here, since they are both from Corsair. Comparing specs from different manufacturers is often meaningless, as they have different testing procedures etc. But if both are from Corsair, then it's not like Corsair is going to intentionally sabotage the rating of the 140.

I too have preferred 140 over 120 in the past, but now I wonder if it's not just a bigger-is-better bias, even more prevalent in the tech circles than outside. It's the same reason that many people buy 200mm, even though they are generally accepted to be quite poor by those in the know.

 

[ClockHound]

@ClockHound, Essence of War - I do like the AF140 QE that I have (blowing on the cards), but I can only put a 120mm fan on the bottom. I want to put a fan there to pull cool air from outside, throw it upwards, where some of it will be pushed by the AF140 towards the cards, as well as getting some to the rightmost Noctua fan.

Ah...that limits the choices a bit.

First choice would be the 120mm S-Flex F, but Scythe stopped making them. Have one mounted in the bottom of a ghost and it performs better than the other 120mm candidates on hand, (Cougar, Silverstone, Antec) and seems to have no issue with the air filter resistance. Not helpful, unless you have some or discover some new-old stock.

What about a GT on the bottom? Probably even better than the S-Flex. Coolerguys have a variety of models: http://www.coolerguys.com/sgt120.html

Any sleeve bearing model is off the list for horizontal mounting.

Am still fanning the flames of ducting, even tho Bonzai isn't allowed to mention it on the weekend. Here's what he did with his NH-D14.

Regarding the heat buildup, it could be that exhaust is not the primary issue, since there is no intake fan in the current config, seems there is not enough cool intake to pressurize the case to force the hot stuff out. This is where experiments can be performed in the safety of your own rig.

And why I advocate the 4 or 5 to rule. Only 1 fan in 4 or 5 makes it into the build. Also helps if the fans don't cost $20+ each.

Maybe we could form an Anandtech Fan Co-op. We could circulate fans amongst ourselves, collect data as well as dust.

 

[Alpha0mega]

Regarding the heat buildup, it could be that exhaust is not the primary issue, since there is no intake fan in the current config, seems there is not enough cool intake to pressurize the case to force the hot stuff out.

Currently I am running just the default fans it came with, a 200mm front intake and 140mm rear exhaust.

The Phantom 530 came with a 200mm fan as intake. It's air flow feels decent at 7v or higher (using the hand to feel the flow).

 

[aigomorla]

i would never replace a 120mm fan with a 140mm fan without looking at application.

The reason is you dont have the wide selection of 140mm fan to fit subjective matter and need.

For example there is NO 140mm fan which can put out the same static pressure a 120mm Nidac Gentle Typhoon can. NONE period.

In the case of heat sinks and radiators, the Gentle Typhoon is the TOP class fan, followed by the Sanyo Denki SanAce.

Also u will NEVER get the reliability on a 140mm class fan that u can find on a 120mm fan.

That is why SERVER's NEVER have anything outside Delta / Sanyo Denki, because those fans can out endurance ANY 140mm fan and provide static pressure to meet ducting needs a server U form case has.

 

[BonzaiDuck]

. . .

Why? The normal reasons for going 140 over 120 are a (slightly) greater area of air flow, and that they are supposed to push more air at lower RPM, resulting in less noise. However, if the 120s are better in every rating, by the same manufacturer no less, like the SP120 is over the SP140, what would be the reason to pick the 140, apart from perhaps the fan mount point not being able to accommodate a 120 for some reason.

The rated specs of the fans are relevant here, since they are both from Corsair. Comparing specs from different manufacturers is often meaningless, as they have different testing procedures etc. But if both are from Corsair, then it's not like Corsair is going to intentionally sabotage the rating of the 140.

I too have preferred 140 over 120 in the past, but now I wonder if it's not just a bigger-is-better bias, even more prevalent in the tech circles than outside. It's the same reason that many people buy 200mm, even though they are generally accepted to be quite poor by those in the know.

The entire fetish was also naïve about static pressure. I was still using two 120x38 SanAce (note Aigo's observation) as exhaust in that project of 2007. There were two bottom 140 Sharkoons in the bottom, and one at case-front bottom.

Now that I look back on it, I'd probably still prefer the 140's no less in their deployment for the 2007 project: as intake fans. Or I might use the opportunity for bigger ones, but there could be the static pressure issue with radiators in the mix without perhaps doubling up in push-pull.

I DID find a good strategy for the cases I'm using: 120 AP-30 exhaust, 120 Noctua iPPC CPU pusher, and only two 200mm intake fans. That's it. Four fans. EDIT: I DID also use a 140mm as center "pusher-puller" with the NH-D14 on the sig. I picked an Akasa Viper 140-R "round" fan because the top-end CFM was rated around 105 CFM and they're quiet. The black frame with the puke-yellow fins would put someone off, but then -- in that NH-D14 deployment, you don't see it anyway.

 

[ClockHound]

The Phantom 530 came with a 200mm fan as intake. It's air flow feels decent at 7v or higher (using the hand to feel the flow).

200mm? Pffft! That's so small. :\

Somehow managed to assume it wasn't in use. Sorry.

 

[BonzaiDuck]

200mm? Pffft! That's so small. :\

Somehow managed to assume it wasn't in use. Sorry.

There are also 180mm fans which could easily fit the vents generally intended for 200mm. BitFenix Spectre-Pro 200 LED's rated by the maker at about 144 CFM; NZXT white and black 200mm @ 166 CFM. Apevia and CM are limp. I think the BitFenix might be the best of those, for the "hydro-dynamic" bearing assembly against the NZXT's rifle-bearing. The others are fans with sleeve bearings, which mildly sucks in relative terms.

Depends on case size, case design, manufacturer application of vent holes and other intentions -- or -- your tolerance for irritated neighbors, metal dust, etc. etc. Oh. Add carpal-tunnel pains to that. Hopefully they're only temporary on a case-mod to case-mod basis.

SECOND THOUGHT -- LET ME ADD SOMETHING TO THAT. The case-makers build a product designed with options. If you can and want to install 120's or 140's in a vent arrangement that also seats a 200mm fan, you can block off the extra vent holes with about 50-cents-worth of foam-art-board cut with the holes compatible with the smaller fans. Nothing lost there and probably better. So no reason to reject cases because they have a 200mm option or come with the larger fan. Looka-me. I replaced limp 200's with better 200's -- not even a matter of different sizes.

 

[ClockHound]

And speaking of you, BD...why aren't you making some feathers fly with your duck, er, duct-work for his D14?

 

[BonzaiDuck]

And speaking of you, BD...why aren't you making some feathers fly with your duck, er, duct-work for his D14?

I dunno, Clocky. I can type faster than I can think, but I've posted a lot on this topic, and my fingers get tired for being 2 years past Medicare eligibility. He can run a search on "Gentle Typhoon . . . 117 CFM" -- shee-**! Here:

http://forums.anandtech.com/showthread.php?t=2370973&highlight=gentle+typhoon+117+cfm

And I could also promote my EVGA ACX discoveries against that D14 -- both similarly ducted. But he already has the D14, so it wouldn't seem worth it to him for between 5 and 6C better for load CPU temperatures. He could "take a walk on the wild side" and replace his exhaust with a PWM AP-30, or more modestly a Noctua iPPC 2,000 or 3,000 RPM-rated 120mm. And make with the Spire acoustic rubber and foam-art-board.

It's all in that thread.

 

[ClockHound]

Thank you and and your tuckered claws, BD.

The foam-art-duck is such a great DIY idea. Needs to be mentioned frequently. And often.

The 530 features a side-intake fan - the AF140QE would be a good fit - would help the GPUs despite the fan mount being a little too forward. Seems it's the shortest path to the GPUs tho.

This is fun, poking around someone else's build. Thanks for inviting us, Alpha0mega.

Hope you let us know what is the optimum solution after you've tried the 20 less optimum ones we've suggested.

 

[BonzaiDuck]

Thank you and and your tuckered claws, BD.

The foam-art-duck is such a great DIY idea. Needs to be mentioned frequently. And often.

The 530 features a side-intake fan - the AF140QE would be a good fit - would help the GPUs despite the fan mount being a little too forward. Seems it's the shortest path to the GPUs tho.

This is fun, poking around someone else's build. Thanks for inviting us, Alpha0mega.

Hope you let us know what is the optimum solution after you've tried the 20 less optimum ones we've suggested.

Starting around 2004, I was cavalier about experimenting with fans and therefore "ordering" fans. If I had spares, I put them in the parts locker with those that get recycled and re-used. Nowadays, I window-shop and research carefully. Then I take the leaps. I often buy two when I'd only use one in forthcoming months. But if the fan works for something, the spare will soon find a home. And with that regimen, it's pretty likely the fan works for something.

Anyway, there are profound and simple ways to isolate vibration and noise on sidepanels, even for budget cases . . .

 

[Alpha0mega]

I considered putting a 140mm fan in the side vent, but the positioning makes it fairly useless for anything except cooling the HDDs. Almost the entire intake will get blocked by the cage. If there is one thing I would criticize about the 530, it would be this intake's position. Would have far preferred it to be in-front of the GPUs.

That's why I decided to put a 120mm below. It should blow air upwards, towards the tail end of the cards, which would then be blown along the cards' length by the internal fan.

Anyway, I am going to order the Corsair SP120 LEDs and try them out. I will try moving them around too, to see if the SP120 is better for blowing on the GPUs or the AF140. I will update this thread about their noise and airflow, since there doesn't seem to be much information about the SP LED fans online.

BTW, the SP120s have hydraulic bearings. Is that ok for running horizontal?

 

[BonzaiDuck]

I considered putting a 140mm fan in the side vent, but the positioning makes it fairly useless for anything except cooling the HDDs. Almost the entire intake will get blocked by the cage. If there is one thing I would criticize about the 530, it would be this intake's position. Would have far preferred it to be in-front of the GPUs.

That's why I decided to put a 120mm below. It should blow air upwards, towards the tail end of the cards, which would then be blown along the cards' length by the internal fan.

Anyway, I am going to order the Corsair SP120 LEDs and try them out. I will try moving them around too, to see if the SP120 is better for blowing on the GPUs or the AF140. I will update this thread about their noise and airflow, since there doesn't seem to be much information about the SP LED fans online.

BTW, the SP120s have hydraulic bearings. Is that ok for running horizontal?

I had another posted project for a more extensive ducting with pairs of intake and exhaust fans through different ducts. I can say for sure that you can build a duct-box that feeds air across both graphics cards, to be sucked out at the cooler or just an exhaust (for a water-cooled system). It can be elaborate yet elegant and optimally functional, but it is also a lot of tedium. If there's pressure in the case, it matters less where the air is coming from or what obstructions are in front if it. So you only would need channel the air through narrow apertures across the graphics cards to further reduce temperatures (and you can measure that: I certainly did for the 2007 project I mention.)

 

[ClockHound]

I considered putting a 140mm fan in the side vent, but the positioning makes it fairly useless for anything except cooling the HDDs. Almost the entire intake will get blocked by the cage. If there is one thing I would criticize about the 530, it would be this intake's position. Would have far preferred it to be in-front of the GPUs.

That's why I decided to put a 120mm below. It should blow air upwards, towards the tail end of the cards, which would then be blown along the cards' length by the internal fan.

Anyway, I am going to order the Corsair SP120 LEDs and try them out. I will try moving them around too, to see if the SP120 is better for blowing on the GPUs or the AF140. I will update this thread about their noise and airflow, since there doesn't seem to be much information about the SP LED fans online.

BTW, the SP120s have hydraulic bearings. Is that ok for running horizontal?

Yes, that bearing style, as well as ball-bearing, are fine for horizontal mounting. Sleeve bearings not so much - as they will lose lubrication and wear out.

Too bad about the side mount blowing into the drive cage and not the GPU area.

Look forward to your results.

 

[Carson Dyle]

I'm a big believer in trying to foster good front to rear airflow, rather than just plugging in as many fans as you possibly can.

** Edit **

Ugh. I just took a look at some better photos of this case. Looks like it can't take two 200mm fans in front, as I thought. If you do add a bottom fan, test both with and without the top fan that you're thinking about.

 

[Carson Dyle]

One other thing I'd consider doing, unless you plan on adding more drives, is to use the shortest drive cage on the bottom that you can get away with, so it impedes airflow from the front fans the least. You could stick your SSD just about anywhere in that case, so you could even use the 1x drive cage for the HDD. Maybe velcro the SSD on the top of the cage or place it the optical bays if one is open.

 

[ClockHound]

One other thing I'd consider doing, unless you plan on adding more drives, is to use the shortest drive cage on the bottom that you can get away with, so it impedes airflow from the front fans the least. You could stick your SSD just about anywhere in that case, so you could even use the 1x drive cage for the HDD. Maybe velcro the SSD on the top of the cage or place it the optical bays if one is open.

Good Point!

If the case isn't moved much, then the hard disk could be suspended with hair elastics from the optical bay cage and the drive cage removed resulting in reduced hard drive noise and improved air flow.

 

[BonzaiDuck]

I understand how it would seem that the drive cage is an obstruction, but think about it: it mostly "obstructs" cool air flowing across the drives in the cage. Even with lower static pressure, it is feeding air INTO the case.

Now . . . get out your metric ruler, download a top view of your motherboard and draw some rectangles around the PCI-/-E slots. Use it as a stencil to cut a piece of foam-board that is exactly ATX size. You'd only have to scale the photo so that a printout (ideally on 11" x 17" paper in "wide" inkjet) perfectly matches the dimensions of the original motherboard.

Next you modify the foam-board so that it fits snugly on the motherboard without being an "interference fit." You modify it to account for "tall" items on the mother board that are more an exception than a rule, or so that air movement doesn't miss anything likely to generate heat, while it flows through the narrowest space that results.

Voila! Your "any-other-type-of-motherboard" is now a "Sabertooth" motherboard. Maybe you cut some holes in the foam board for some strategically-place 40mm Sunon Mag-Lev fans -- forcing "general case-interior" air into the space between the foam-board and the motherboard. And (for the 15,000 RPM top-end of the Mag Levs), you control the fan(s) from maybe just a single 3-pin motherboard fan port, if the fans (plural) are wired in parallel.

I had mentioned this concept with regard to a box over one or more vid cards. With these new cards like my Gold LE "gaming" GTX 970, you don't "cover" the vid card; you simply channel the air down the back side of it by mating the duct to the over-sized plastic duct of the graphics card. With double-vid cards, you could probably have the air-flow limited to the two fans of the lowest card, which would then feed through the two fans of the upper card, then down through the motherboard duct and out the edges of the "Sabertooth" conversion. Now you have warmed the case interior by some small increment, but all that case air gets sucked back through the CPU cooler and out the rear exhaust.

 

[Alpha0mega]

One other thing I'd consider doing, unless you plan on adding more drives, is to use the shortest drive cage on the bottom that you can get away with, so it impedes airflow from the front fans the least.

That's what I had done earlier, used the shorter drive cage. I later switched to this one for one reason. The largest drive cage come with a 140/120mm fan mount, which can be swiveled within about a 30 degree angle. When I went with SLI, I put in the big cage, removed the screw that limited the swivel angle, and flipped it completely so that the fan was now above the drive cage (as can be seen in the photo) rather can flush with the side of it.

This allowed far better airflow as there was nothing impeding the the intake of the fan. I have considered eventually eliminating the drive cage altogether and zip-tying the fan to the optical bay. My motherboard has a M.2 X4 slot, and I hope good M.2+NVMe drives come out, and are reasonably priced, by the end of the year. I am also considering removing all my media/storage HDDs from the main system, and building a HTPC/NAS/download station. Mainly because I find the noise of the HDDs annoying, and a GB ethernet link should be enough for media drives, since sheer performance isn't a big deal in that usage scenario. This should also reduce the heat in the system, caused by the intake air being warmed by the HDD heat.

 

[BonzaiDuck]

That's what I had done earlier, used the shorter drive cage. I later switched to this one for one reason. The largest drive cage come with a 140/120mm fan mount, which can be swiveled within about a 30 degree angle. When I went with SLI, I put in the big cage, removed the screw that limited the swivel angle, and flipped it completely so that the fan was now above the drive cage (as can be seen in the photo) rather can flush with the side of it.

This allowed far better airflow as there was nothing impeding the the intake of the fan. I have considered eventually eliminating the drive cage altogether and zip-tying the fan to the optical bay. My motherboard has a M.2 X4 slot, and I hope good M.2+NVMe drives come out, and are reasonably priced, by the end of the year. I am also considering removing all my media/storage HDDs from the main system, and building a HTPC/NAS/download station. Mainly because I find the noise of the HDDs annoying, and a GB ethernet link should be enough for media drives, since sheer performance isn't a big deal in that usage scenario. This should also reduce the heat in the system, caused by the intake air being warmed by the HDD heat.

I only threw in my additional perspective, which bodes a certain tedium, time and trouble. The basic precept of the ducting means there are "two boxes" (or more) -- the case, and any ducting with helper-fans on the inside. But drilling out pop-rivets or moving drive cages is also tedium.

The most efficient use of intake air within a computer case involves channeling it across all the heat-generating components through narrow spaces. Intake air with drive-cage or other obstructions still pressurizes the case, and that pressurized air can be further directed accordingly.

With tedium, time and trouble. Some glue and an Xacto knife, among other items.

 

[Carson Dyle]

I am also considering removing all my media/storage HDDs from the main system
...
This should also reduce the heat in the system, caused by the intake air being warmed by the HDD heat.

I think you're overthinking it somewhat. It reduces heat simply by removing a heat-generating component from the system. Don't worry so much about its position in front of an intake fan, except as mentioned above - impeding airflow.

You haven't mentioned (or maybe I missed it), are you actually having overheating issues or even just unusually high temperatures? As they say: If it ain't broke...