Cooling Tips: Achieving better acoustics with the Asetek 645LT

AseDen

Cable-Tie Ninja
Original poster
Asetek
Dec 7, 2018
194
295
www.asetek.com
Greetings Small Form Factor Guru's!

I've been listening for a while, and it seems that there are some, who experience some quarrels with the 645LTs acoustic performance.
From what I've been able to gather it is mostly people who are in close proximity to their case and/or users where the radiator is mounted below (on the vertical axis) the pump.

This kind of mounting will inevitably lead to microbubbles getting caught in the pump, giving you a degraded acoustic performance...
And as a fellow SFF nerd, I feel your pain!

That's why I put it on myself to venture into the corners of our offices, to find the most nerdy and skilled engineers at Asetek.
And I challenged them. I challenged them to come up with a potential fix for our beloved 645LT users, who want to make the utmost of their product.
The road has been filled with interesting discoveries, but now I am ready to actually talk about a way that you can achieve better acoustics with your existing 645LTs. EVEN IF they are mounted below the pump (on the vertical axis).

Through rigorous testing, we've found a way to minimize microbubbles in products like the 645LT while having the often desired orientation in SFF.
What you will want to do, is to flip your radiator 180 degrees. That means, tubes at the bottom, rad at the top. This will allow the tank to catch most/all microbubbles leading to a much better acoustic performance in your system and seemingly no more "gurgling"

I know the solution is not perfect. Because at least Dan-Cases A4-SFX won't allow you to fasten it in that position (though it shouldn't matter, as long as you don't start tossing your case around) - but maybe this could be a challenge for @LoserCard if the solution proves to be as good in reality as we have experienced in-house.

Questions?
I'm always happy to answer here, on twitter, Reddit or your preferred social platform!

Happy hacking,
AsetekDennis
 
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raldian

Chassis Packer
Sep 5, 2018
14
2
So configure it like this?
If i just rotate the case so the rad is on top for a while (let's say for 30 minutes, then rotate it back), can this minimize the microbubble?
 

AseDen

Cable-Tie Ninja
Original poster
Asetek
Dec 7, 2018
194
295
www.asetek.com
So configure it like this?
If i just rotate the case so the rad is on top for a while (let's say for 30 minutes, then rotate it back), can this minimize the microbubble?

Exactly like that! :)

Yes it will help rotating it for a while. However, they might reappear at a later point. By flipping the radiator permanently, they will also stick in the radiator permanently :)
 

joconnell

Average Stuffer
Jul 23, 2019
58
8
@AseDen dragging this one up from the archives - any idea what fan and screws this was? I was using a low profile noctua on top of my 645 and when I tried flipping it, there wasn't enough height in the fan to cover the right angle fittings on the block. It also seemed like it'd be really tricky to get the PSU back in afterwards even with the pslate cables, are there any other variations / add ons in the setup above that I'm missing? Like anything to higher up the PSU or the such? I'm running a 3950x happily and looking at adding in a 3080TI FE when they release so anything I can do to make the build better is worth doing!

Out of interest, what does the degraded acoustic performance sound like in this case? I find the asetek to be a high pitched note, what do the micro bubbles sound like in case my setup is totally fine and I'd be changing something for no reason?
 

AseDen

Cable-Tie Ninja
Original poster
Asetek
Dec 7, 2018
194
295
www.asetek.com
@AseDen dragging this one up from the archives - any idea what fan and screws this was? I was using a low profile noctua on top of my 645 and when I tried flipping it, there wasn't enough height in the fan to cover the right angle fittings on the block. It also seemed like it'd be really tricky to get the PSU back in afterwards even with the pslate cables, are there any other variations / add ons in the setup above that I'm missing? Like anything to higher up the PSU or the such? I'm running a 3950x happily and looking at adding in a 3080TI FE when they release so anything I can do to make the build better is worth doing!

Out of interest, what does the degraded acoustic performance sound like in this case? I find the asetek to be a high pitched note, what do the micro bubbles sound like in case my setup is totally fine and I'd be changing something for no reason?
Hi mate :)

So there is a mod that slightly raises the PSU. However, I can't remember the exact name at this point in time. It should be searchable on Reddit, though :)

Degraded acoustic performance usually has a "rattle" to it. Basically it's the noise that you would encounter without the pump being completed submersed. This is due to the fact that the liquid doubles as the lubricant for the pump.
Generally, the 645LT has a high pitch not at full speed. You can reduce the pump speed thus reducing it's acoustic foot print, but also with a slight reduction in thermal performance.

LMK if I can assist you further :)
 
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Deleted member 23607

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Hi mate :)

So there is a mod that slightly raises the PSU. However, I can't remember the exact name at this point in time. It should be searchable on Reddit, though :)

Degraded acoustic performance usually has a "rattle" to it. Basically it's the noise that you would encounter without the pump being completed submersed. This is due to the fact that the liquid doubles as the lubricant for the pump.
Generally, the 645LT has a high pitch not at full speed. You can reduce the pump speed thus reducing it's acoustic foot print, but also with a slight reduction in thermal performance.

LMK if I can assist you further :)
"Losercard mod"
 

tygercat

Minimal Tinkerer
New User
Jan 4, 2021
4
0
have you guys thought on keeping the dan a4 inclined over its front edge with some sort of mount?
 

MuFF

Efficiency Noob
Apr 14, 2021
6
1
Hi! I am new to the sff community!

I have the geeek n500lite case. I just ordered the i5 11600k and its tdp is 125 according to intels site. Will the asetek645lt be able to keep temp cool?

Kind regards,

Dominic
 

elvendawn

Average Stuffer
Nov 12, 2020
60
27
It can keep my 5600x @ gaming loads around 55c (stock clocks, pbo2 enabled), max loads around 65c in Cenabench. Using the below articles as reference the 10600k is using about 35 watts more under load, I highly suspect it will be more than fine at stock clocks.

Update: Also of note my 645LT is using an NH-A9X25 instead of the A9X14 that came with it, I suspect it's affecting temperatures by some small amount but I didn't compare the numbers.

 
Last edited:

elvendawn

Average Stuffer
Nov 12, 2020
60
27
@MuFF - An update to my previous statement, the 11600K uses 257 watts at load, sorry I miss read 10600k above. That is 110 more watts than the 5600x at load, so not sure I would recommend it strongly, but I see others using it for the 3900X which will have a similar load wattage, the CPU might get pretty toasty with the 645LT. If that case supports a 120 or 240 AIO I suggest getting one of those, however if you are dead set on the 645LT, I would look into undervolting the CPU, Optimum Tech on YouTube has some good videos about it.

 

MuFF

Efficiency Noob
Apr 14, 2021
6
1
@MuFF - An update to my previous statement, the 11600K uses 257 watts at load, sorry I miss read 10600k above. That is 110 more watts than the 5600x at load, so not sure I would recommend it strongly, but I see others using it for the 3900X which will have a similar load wattage, the CPU might get pretty toasty with the 645LT. If that case supports a 120 or 240 AIO I suggest getting one of those, however if you are dead set on the 645LT, I would look into undervolting the CPU, Optimum Tech on YouTube has some good videos about it.

Thanks Bud!

I got the geeek case n500 lite. It does not have the options for anything else. I know this isnt the thread for it but can you recommend something for it please?
 

elvendawn

Average Stuffer
Nov 12, 2020
60
27
I found this video, if you leave the 11600k at stock power limits, it will likely be fine. This guy tested a 10900K (which will use bit more power than the 11600k) with the power limit disabled, and with it enabled (default for most motherboards). In the former case the 645LT could not keep up, however in the latter case it did fine. So if you plan to leave the power limit stock at 125 in the bios you are probably fine, however if you want to remove that limit go with a 240mm AIO. He measures about 11% performance difference.

The 645LT is the second AIO I've ever used, I mostly stick to air cooling, so I'm not really an authority to make recommendations, however if you want similar to the 645LT, Asetek also makes a 240mm AIOs like the 670LS (27mm thick) or 670LT (38mm thick). Lot of other brands that use the Asetek pump blocks out there too.

NZXT Kraken X53 (or Z53) seem to benchmark really well and I believe are pretty popular. If you have better access to European retailers Alphacool and EK have some good 240mm AIO options.
 

MuFF

Efficiency Noob
Apr 14, 2021
6
1
I found this video, if you leave the 11600k at stock power limits, it will likely be fine. This guy tested a 10900K (which will use bit more power than the 11600k) with the power limit disabled, and with it enabled (default for most motherboards). In the former case the 645LT could not keep up, however in the latter case it did fine. So if you plan to leave the power limit stock at 125 in the bios you are probably fine, however if you want to remove that limit go with a 240mm AIO. He measures about 11% performance difference.

The 645LT is the second AIO I've ever used, I mostly stick to air cooling, so I'm not really an authority to make recommendations, however if you want similar to the 645LT, Asetek also makes a 240mm AIOs like the 670LS (27mm thick) or 670LT (38mm thick). Lot of other brands that use the Asetek pump blocks out there too.

NZXT Kraken X53 (or Z53) seem to benchmark really well and I believe are pretty popular. If you have better access to European retailers Alphacool and EK have some good 240mm AIO options.
Legend!

Sadly I cant fit any 120 or 240 in the case I am using and no I wont go above the stock power unit. See link below. I checked am looking at other solutions. Bequiet makes some good ones. Thanks mate!

 
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elvendawn

Average Stuffer
Nov 12, 2020
60
27
If you are looking at air cooling too, you might want to check out the Noctua NH-U9S (also comes in chromax.black), it's only 125mm high (your case supports up to 135mm of height) and should also work fine with 125 watt stock load. And you can put a second 92mm fan behind it with a push/pull configuration. Also if you can mount the 120x15mm fan at the top towards the middle of the case, it might help get fresh air in front of the cooler for even better results.

Push/pull to exhaust out the rear is likely the best air configuration for this case due to the TG panel on the side.