4000D Airflow Fan Orientation Testing; 1 v 2 CPU Fans. Extra case fans. Temps & Noise comparisons.

[Ralfi]

7 hours ago, thrasher_565 said:

and its probly not a simple as adding another fan. what fan you add is also imported.

 

17 hours ago, fonzz1e said:

afaik usually cpu cooler with 2 fans, they are using the same model fan with high static pressure

example, noctua nf-u12a using two nf-a12x25

Yeah that’s right. I think having a different number/size of fan blades doesn’t help. Couple that with unmatched RPM’s & you may have a CPU heatsink bookended by fans that aren’t expelling air efficiently. In fact, they could be trapping some air inside, even for long enough where it’s better to just have one fan that’s unhindered by anything on the other side of the heatsink, as above was shown to perhaps prove.

[thrasher_565]

3 hours ago, Ralfi said:

 

Yeah that’s right. I think having a different number/size of fan blades doesn’t help. Couple that with unmatched RPM’s & you may have a CPU heatsink bookended by fans that aren’t expelling air efficiently. In fact, they could be trapping some air inside, even for long enough where it’s better to just have one fan that’s unhindered by anything on the other side of the heatsink, as above was shown to perhaps prove.

ya its complicated to say the least.

 

i would think you want the back fan faster then the front

 

fans can vary in speed by +-10% even if there the same fan. that's why gn labels his fans for the noise normalize testing so the same fan gets used in the same spot.

[Ralfi]

1 hour ago, thrasher_565 said:

that's why gn labels his fans for the noise normalize testing so the same fan gets used in the same spot.

I wonder how much that margin of error is decreased with noise normalised testing? I ask because with some fans, the same noise level’s achieved within a fair range of RPM. 

[thrasher_565]

3 minutes ago, Ralfi said:

I wonder how much that margin of error is decreased with noise normalised testing? I ask because with some fans, the same noise level’s achieved within a fair range of RPM. 

the noise normalised  is for the whole pc not just 1 fan.

[Demonic Donut]

Interesting read.

 

How do you like the 4000D overall? I'm thinking of getting one for my daughter's first computer. But the lack of 5.25 bay makes me hesitate. I like having a DVD/blu-ray drive.

 

Your case fan setup results are the same as mine. I run the top front as intake and top rear as exhaust. Although I have a side and bottom intake as well.

 

I have a Noctua D15 and I will say I got a very minor CPU temp decrease (iirc 2 ish degrees) by having a second fan. So my cooler goes 120mm fan -> fin stack -> 140mm fan -> fin stack -> 140mm rear exhaust. But with a dual tower cooler it makes sense to have two fans. I ran without the 120mm for a bit because the 140mm wouldn't fit due to ram.

[Ralfi]

2 hours ago, Demonic Donut said:

How do you like the 4000D overall?

My thoughts pasted from another website...

 

Great case! Very easy to build in, cable-management is a breeze & build quality is good for the most part (only negative are the fan mount frames - a bit thin for my liking, so watch the tightening of your fan screws & line them up straight/flush).

It's best feature is in the name: Airflow - get the right fans & things will stay cool. I don't have the best CPU cooler but i've added quality fans to it & the rest of the case (removed the Corsair fans it came with, though they weren't too bad) & my components are comfortable, temp-wise. Playing with fan curves helps things further proving how practical this case design is.

It was a tight fit beneath the PSU shroud when HDD's are used [& in the rear-most HDD cage position], but it was ok [if using the front-most HDD cage position, it'll be much easier]. But once I went all NVME M.2, there's plenty of room under there. I recommend you ditch those HDDs ASAP!

2 hours ago, Demonic Donut said:

But the lack of 5.25 bay makes me hesitate. I like having a DVD/blu-ray drive.

Hmm yeah your only option is to have an external drive if that's the case.

[Ralfi]

More testing today, this time with the 80mm Noctua fan mounted as an intake, directly beneath one of the 6700XT intake fans. So this was more a GPU temp test...

 

Ended up using the case's SSD mount to attach the fan to + made use of the Noctua noise dampeners to prevent any vibration...

 

 

Results...

FurMark Stress Test, 60 minutes...

LOAD CPU Temp over Ambient: +46.7° (2.6° higher than best)

LOAD GPU Temp over Ambient: +54.3° (2.5° higher than best)

LOAD GPU (Hot Spot) Temp over Ambient: +65.3° (3.5° higher than best)

LOAD Noise: 37dB (same as best)

 

So, not worth keeping this orientation either.

 

I plan on making a 'funnel' into one of the GPU fans next. Stay tuned!...