Aurora R7, AIO radiator fan size?

MH0HN (R6 R7 R8) & 050NP (R5) are the part#'s for the liquid cooling assembly, & those tend to be paired to the PP749 fan (in use for a decade) which is a 120x38mm 4pin PWM type approx. 1.4 - 1.5Amp 147CFM server-grade Nidec / Delta

The part# dp/n for your fan is on a label & can be checked

I don't own your desktop nor know which is a better (& quieter) 38mm wide fan, nor know if 32mm wide or slimmer 25mm wides will fit (slimmer fans tend to be rated 1Amp & lower & can run quieter but maybe not push as many CFMs as the result), Noctua or Corsair high static pressure fans might work, so long as 25mm wide fans are ok in your cooling caddy; I suspect using a different 38mm wide type will result in a side-grade as compared to PP749 but google is a good way to look for quiet 38mm types, all types

'All fan frames that are 120mm are alike', so long as you buy a 4pin PWM type they all have the same mounting hole layout, no 'modding' should be required

***One wonders if two 25mm fans in push-pull (one fan on top of radiator, one underneath) while using a y-split adapter cable (two fans off of one fan header) would fit & be a decent config to attempt***

***edit to new question below regarding fan amperage: the Area-51 R1 & Aurora R1 debuted in late 2009 with 38mm Delta / Nidec 1.4 / 1.5 / 1.6 Amp radiator fan PP749 & at the time, there was a consensus in the computer world & so in this forum that mthrbrd fan headers should not exceed 1.0Amps; we assumed that ~1.5Amps (18watts) was the max safe amperage for an alienboard & so a 3.0Amp fan (36watts) would not be considered ok for use --> for push-pull dual-fans, the max would be a pair of 0.75Amp fans so as to stay w/in the 1.5Amp limit***

Do wait for other member input

Thank you for the info.  Looks like a 120x38mm, 4-pin PWM fan or thinner would work in my computer. However, the Nidec currently installed is a 1.4 amp unit whereas most 38mm fans I'm seeing online are in the ~3A range.  Would the motherboard fan header in the R7 be capable of supplying 3A peak for sustained periods of time?

Edit: ordered a Noctua A12x25 and Noctua NF-F12 iPPC-3000.  Will try the NF-F12 first.  Hopefully it'll run fine without triggering ePSA boot errors.  If it does, then I'll throw the A12x25 up front.

BTW, is removal of the PSU absolutely necessary when taking the cooling system out of the chassis?  The service manual indicates as much, but looking inside the tower, it seems once the side panels and top panels are removed and the PSU swung out of the way, removal of the cooling block and radiator assembly seem straightforward.

Edit: never mind.  Misread the service manual.  They just want you to swing the PSU out of the way; not remove it completely.  Although the YouTube videos show them removing the PSU and DVD drive to access the cooler.  Made no sense...

Ideally you want the Dell part as listed above but they are next to impossible to find.  Anyways, it is not all doom and gloom.

You don't need to remove the power supply, it swings out of the way to give plenty of space.  The manual says to do this but it is a precaution - just press the test button to discharge the supply.

See my post below on how to fit corsair H60 - keep the original top fan as it pushes far more air than the corsair fan. 

This is adequate - depending on the fan profile, it keeps temperature down to around 70 when running the prime95 tests (default test) without hardly any increase in fan noise, under normal operation i.e. gaming, temperatures don't get that high as it is the card(s) doing the work.

I initially bought the H80i but that may be harder to fit as it has two fans so cannot use the same CPU fan connector plus it has thicker hoses that may be harder to route - the hoses posing the biggest problem so that nothing is squashed when the PSU cage comes down. 

Not sure if I mentioned it in my post, but the pump goes to CPU PUMP on the board and radiator fan to connector labelled TOP FAN as opposed to CPU FAN, the one used for air cooling; otherwise you'll get some error about fan failure when starting up.

https://www.dell.com/community/Alienware-Desktops/Aurora-R7-fitting-Corsair-H60-water-cooler/m-p/6231480#M7333

**One wonders if two 25mm fans in push-pull (one fan on top of radiator, one underneath) while using a y-split adapter cable (two fans off of one fan header) would fit & be a decent config to attempt***

I wondered about this.  Push fan is always better since it is capable of compressing air above atmospheric pressure, whereas a pull fan can never pull more than one atmosphere.

In my non expert opinion, one strong push fan will be better than two weaker pull fans for the above reason.  If it was that good an idea, why isn't that combination fitted to cars?

The original top fan, forget the brand but astek? springs to mind, pushes more air than the one supplied with corsair H60 and wither of those with the H80i, the H80i slightly more powerful than the H60 - I measured the current drawn and felt the air flow and the original top fan was best.  Also the motherboard is capable of driving this fan.

Got around to replacing the fans today in my R7.  What a difference.  Front fan is a Noctua A12x25 and top fan is a Noctua NF-F12 iPPC-3000. 

Here's the weird thing though; with the pump connected to the FAN_PUMP header, and the NF-F12 connected to the TOP_FAN header (which is how the OEM components were connected to begin with), I still get the ePSA BIOS boot error.  Interestingly enough, the NF-F12 will remain off during system start and only spin up once Windows loads and Dell's thermal controller application opens.  Thinking the fan may be the culprit, I also tested with two Corsair ML120's that I also bought just in case the Noctua's gave me problems.  Same story with the Corsair's unfortunately.

ePSA diags show 0 RPM at test start with the fan eventually ramping up to about 2700 RPM.  Of course ePSA flags it as a failed component because it can't reach the target of 3,700 RPM.

So, not sure what to do at this point.  And yes, I did find a brand new Nidec B35502 fan on eBay.  Only difference between that part and the one that came out of my PC is the Dell p/n.  Original has PP749-A02, whereas the fan I purchased is PP749-A00.  Apart from that, the specifications are exactly the same.

I'd hate to go back to the OEM fan since the Noctua's are very quiet.  Any suggestions on how to get past the ePSA boot error?

Thanks for the info.  I assumed 3.0A would have been pushing it; hence my decision not to go that route.

The Noctua's in my R7 are all rated at less than 1A peak draw so the motherboard should be safe.  Also, I've been experimenting a little bit.  The factory Nidec 35502 fan powers on with a base speed of ~1700 RPM.  As long as ePSA sees something with an RPM of 1700 or higher on the top fan header, it clears post without issue. 

As an example, plugging the CPU pump into the TOP_FAN header and plugging the Noctua into the CPU_FAN header results in no ePSA or BIOS errors during boot as the pump's impeller is chugging along at over 5k RPM.  I would have left it like that but then Alienware's thermal management application has no provision to control or even monitor the CPU_FAN header at all. So, no curves can be applied and it can't be monitored.

But, unlike when the Noctua NF-12 is plugged into the TOP_FAN header, when it's attached to the CPU_FAN header, the blades do spin at power on.  Very strange indeed...

I see you decided on slimmer 25mil fans, I'll try to get the below info you asked about into other people's hands > most 38mm fans I'm seeing online are in the ~3A range.  Would motherboard fan header in R7 be capable of supplying 3A peak for sustained periods of time?

No, I don't think so

We have to be protective of the micro-thin copper wire motherboard traces & not burn them out from too much current draw

In computer forums & online over the past decade, the question 'what is the max safe amperage that a mthrbrd fan header should pull?, was considered to be 1.0Amp / 12watts as a rule-of-thumb

Area-51 R1 | Aurora R1 debuted in late 2009 w/a 38mm Delta | Nidec 1.4 - 1.6 Amp radiator fan (example PP749) & this forum felt that Dell was confident that ~1.5Amps / 18watts is a max safe amperage for alienboards & to exceed ~1.5Amps wasn't a good idea

1Amp rule-of-thumb? Well, notice how in the past few years, top-tier mthrbrd makers started to offer new 'dedicated' cooler pump headers, where the marketing said 'new dedicated pump header w/a beefier 1Amp rating' - as compared to the basic CPU Fan header right next to it (where the cooler pump would otherwise normally go) rated at what exactly? - less than 1Amp??? I assume (***whether boards these days have pump headers rated above 1Amp isn't our concern, some probably do)

3.0Amp fan (36watts) would not be considered ok for use in my opinion

For push-pull dual-fans, a pair of 0.75Amp MAX each (1.5Amp total, as is the original rad-fan)

Single push, single pull, dual push-pull is a topic that can be looked at online / uTube etc ... here we see wider 80i V2 w/ solo fan may be a smidge better than slimmer H60 w/dual-fans. Which fan or fans is best to buy isn't an easy question to answer, given the assortment & design differences out there (amps, RPMs, CFM, static-pressure, decibels, price, reputation etc). 'Noctuas are good, & quiet!', is one way to go about it

'keep original top fan, pushes far more air than corsair fan', is another way

(original top fan, forget the brand but Asetek? > cooling assembly Asetek, fan Delta | Nidec)

I've swapped my original 38mm fan for 32mm Everflow FB1232BU (1Amp 134 CFM & a tad quieter, but they can be hard to find these days) paired to 01YGW 38mm Asetek radiator (from Aurora R4 > special connector-end removed/replaced w/connector-end I need)(I do not own Aurora R5-R8)

After talking to someone on an Alienware reddit forum, I returned the standard ML120 Corsair fans and purchased an ML120 Pro.  Based on the published specifications on Corsair's website, you'd think there'd be no difference in terms of motor used in either fan, but there is.  Where the Noctua's and standard ML120's wouldn't spin on boot when connected to the TOP_FAN header thereby causing an ePSA boot error, the ML120 Pro fan does spin up on boot.  Problem solved!

So now I have my R7 with a Noctua A12x25 up front and a Corsair ML120 Pro as the radiator fan.  The computer is dead quiet except for a low hum from the water cooler block.  If anyone wants to swap their radiator fan for something quieter, I can attest that the ML120 Pro will work without causing boot errors.

I think top_fan head needs a fan with RPM>= 3700 to pass BIOS check, not 1700~ 

Since CPU fan RPM is over 5k, thats why it will work if you swap between cpu_fan head and top_fan head.

ML120 Pro is 2400rpm. No boot failure.

interesting. Thanks for sharing. I will get ML120 PRO for top fan then.

Is it very loud in general ? I want to replace the front fan and add extra top front fan as well for my R9, That will be three ML120 PROs in this case.....

The ML120 Pros can get loud once it goes beyond 2000 RPM. However, they are loud with a nice tone, unlike the stock fans. I have 3 case fans for my R8:

2x ML120 Pros for push-pull across the top radiator.

Noctua AF12x15 for intake across lower front radiator post-GPU liquid cooling mod.

For optimized fan setup in the R9, please refer to @Bmwpower603's R9 Arrival post which you are already participating in.

My friend told me, top fan error is related with BIOS setting about PWM duty circle and mini speed of fan. 

The RPM of new top fan has to be larger than certain RPM when it is given the testing PWM duty circle when PC starts. This problem can be avoided when using a commercial motherboard that you can change the BIOS PWM signal as you wish compared to locked Dell BIOS.  

ML120 PRO PWM/RPM relationship can be found here :https://www.techpowerup.com/review/corsair-ml120-pro-rgb/5.html   

Basically, if the new fan has minimum RPM>500 and can still be runnning with less than 30% duty circle, then it should pass the BIOS check and work on top fan head.

How did you setup your push-pull fans for your  R8 ?  

I want to do it on my R9 too.