Recommended Heat Sink(s) and/or Fan(s)

HiFive Unmatched
21

It looks like there are power saving modes for ASM2824. So it could be run, perhaps, in lower power modes to keep cooler:

  • Support L0s/L1/L23/L3 power saving states
  • Support L1 substate deep power saving mode
  • Support wake up function in S3/S4
1 Like
22

Thanks. My case actually slopes a bit toward one side so I will just have to check once I hopefully get the Unmatched in the coming weeks.

1 Like
23

Has anyone had any luck mounting it in a 1U chassis? Iā€™m not sure the exact measurements but if it fit, it will be tight.

24

I havenā€™t received my Unmatched yet, but after reading a lot about the noisy fan i started searching for alternatives.
I came across passive cooling solutions designed for Intel/AMD systems, they are capable of cooling 35W CPUā€™s. Wouldnā€™t it be possible to adapt one of those to the U740?

25

It sounds like a '90s era PC, which I quite like, because nostalgia.

Mounting it properly is the only problem I see.

2 Likes
26

I got my Unmatched running since yesterday and the fan is really annoying me. Itā€™s way too loud for my comfort and the high-pitched noise makes it even worse :roll_eyes:

Looking for solutions, I did find a few 25mm->40mm fan adapter models for 3D printers and that would mean I could fit a 40mm Noctua fan. The Noctua 40mm fans have a higher airflow than the standard fan, the pressure is a bit lower, but that might be compensated when the air flows through the adapter (the same amount of air running through a smaller hole makes higher pressure).
Did anyone try such a setup?

1 Like
27

Yes. See also my previous post :slight_smile:

My HiFive Unmatched is using the 40mm to 25mm fan adapter with a 40mm Noctua and 120mm chassis intake fan. Itā€™s sitting silently at 36.8Ā°C MB/46Ā°C CPU after 4 days of package(s) compilation at 25Ā°C room temperature and 60% humidity.

The 40mm Noctua fan alone does not have enough CFM to cool the CPU efficiently. A4x20 FLX is a 5.5 CFM fan, but since the surface area is larger, the airflow output is lower as a result. In this setup, an intake case fan is required to compensate the airflow.

Itā€™s much easier to find a silent 120mm chassis fan, so in the end it should still result in a much more silent setup.

1 Like
28

Thanks for the link to that post. I did remember reading something about it but couldnā€™t find it anymore :slight_smile:
What kind of case are you using? Mine is on a BC1-Mini which is basically just open-air.

29

Iā€™m using Cooler Master NR200 because I live in a dust-prone country. Iā€™m not sure how effective the cooling will be in case of an open case like BC1 Mini (without chassis fan in this case).

30

I finally got around to replacing the CPU fan. Iā€™m using a Noctua A4x20 FLX with this adapter I found on Thingiverse. I found that M2.5x20 screws were perfect for attaching the adapter (the ones from the stock fan were too long). Assembling the whole thing was a bit fiddly, since you canā€™t reach the adapter screws through the fan blades. The A4x10 would probably be easier to work with.

After running four instances of shasum /dev/urandom for about 30 minutes, the temp2 sensor settled at just below 63C. Definitely warmer than with the stock fan, but not dangerously high either. The noise level is just ridiculously improved. I actually had to open up the case to verify that the CPU fan really was running.

5 Likes
31

yeah, I got one, every every useful , thank you