Log Acat X2 + 5950x + 3090 + active 280/280/280

evadne

Trash Compacter
Original poster
Jan 15, 2020
46
50
I have drunk the Acat X2 koolaid and here is a build in progress! Yes, I think as long as it is under 20 litres, you could call it SFF?!


Summary of this build:
  • 5950x / 3090 / 64GB RAM
  • 3x active 280mm radiators
  • DDC pump

Changes in this build compared to the previous one:
  • Pump is reworked and moved away from the side radiator; the pump top actually cracked open but somehow the liquid was contained due to how tight I have built in the DA2 and all parts survived. In the new build, the same leak would not be catastrophic (theoretically)
  • CPU block changed from EK Quantum Velocity to Optimus Foundation
  • GPU block remains EK 3090 (RE), but all thermal pads were changed to Thermalright (vs. Stock from EK)
  • MP5Works backplate was added to cool the back side of the card, and to aid tube routing
  • Tubing changed to Mayhems, very satisfied as there is no clouding (Mayhems X1 Eco clear coolant is used) compared to EK DuraClear which I have previously used.

Performance wise, here are the temperatures from the past 7 days, but without the top radiator installed yet
  • CPU is PBO-enabled with 200W PPT / 175A TDC / 150A ETC; scoring 27600 (Multi-Core) in Cinebench R23 at 55 to 65°C-ish
  • GPU has custom curve and custom undervolt (tested with Control & Cyberpunk 2077, w/ RTX stable), power limit @ 390W



Now onto the build. (Much has been posted regarding this case so I shall skip the introduction.)


↓ De-aeration in progress. You can see how the MATX bracket looks when installed. Note the 1st DisplayPort on the 3090 is slightly blocked by the retention bracket, you will need a low profile connector to access it.




↓ GPU Area / Side radiator is GTS 280 which has tubes on both sides so it is quite wide and not easy to fit. Fans are mounted in push configuration. The Acat X2 case comes with 2 horizontal brackets to mount the radiators, so with 2 additional Singularity Computers brackets I could mount the radiator slightly above where the designer has intended. Many M4 nuts were used to build this contraption.




↓ Old Layout; can see how the top and bottom modules are installed and roughly how things are spaced out.




↓ The top module has a few 90-degree rotary fittings to facilitate installation and removal.




↓ Bottom assembly; The MATX bracket is shown here + Corsair XR5 280mm radiator installed. Pump is modded DDC with EK X-TOP + Koolance bracket + two layers of thermal pads (a thick one to fill the air gap, and a thin one with adhesive on both sides). Additionally, the pump rests on top of thick foam pads (taped to the angle brackets shown) so vibration is somehow absorbed.




↓ Bottom assembly is installed first; the adhesive helps keep the pump in place, so the entire front panel becomes the heatsink for the DDC pump. The flow meter is also mounted here (AquaComputer High Flow LT). Note the mounting rail and 2 M4 screws; they are in place to provide support to the GPU once it is installed, as the entire assembly (GPU + water block + active backplate) is quite heavy. You can also see that foam pads and rubber pads have been added strategically to the motherboard tray, to help hold the motherboard and PSU in place during assembly.




↓ GPU Assembly. In my hands the whole thing must weight 2kg or so (might be lighter in reality)




↓ GPU assembly from the side; note the single-slot bracket is tried here but it turns out to conflict with the case, so I have reverted to the original 2-slot bracket.




↓ Octo is mounted right above the PSU with one of the included brackets + some machine screws and washers. Note that in practice it should be insulated with a plastic sheet to avoid accidents!




↓ Top view, note Alphacool ES quick disconnect fittings are used instead of QD3 etc. This is due to 2 reasons: 1) QD3 takes too much force to operate, 2) QD3 is too thick




My final thoughts regarding the Acat X2 case:
  1. The designer wishes to not expose screw heads at all. In my opinion this has made the case very difficult to work with, because once the case has been filled with components, you can not even attempt to screw or unscrew some screws due to severe lack of space
  2. Tolerances are too tight in some areas and too loose in some other areas, so you better know where and how to apply tape
  3. Threading is bad and one of the motherboard standoffs was actually crooked due to the screw hole being crooked
  4. Surface finish is excellent but colour matching is bad
  5. No comment on air flow, as I do not intend to actually put the side panel back on

Summary. Good idea but mediocre execution. OK for the price. Would like to see better QC next time. If you want to build in this case, you better have several tweezers at hand.
 

zk2004mb

Average Stuffer
May 23, 2020
58
32
Beautiful layout. It's amazing that you can fit triple 280 rads into it. But have you tested the water flow rate? When I worked on my triple rad build, the flow rate with a single DDC was shockingly low.
 

evadne

Trash Compacter
Original poster
Jan 15, 2020
46
50
Beautiful layout. It's amazing that you can fit triple 280 rads into it. But have you tested the water flow rate? When I worked on my triple rad build, the flow rate with a single DDC was shockingly low.
Thanks, current flow rate is 110 to 115 l/h at full speed, 55 l/h at half speed, this is with a 12W DDC.

Getting rid of all air pockets and removing all possible gunk was very important. This contributed to a roughly 25% gain of flow rate in my scenario, and I was using new coolant after running Blitz!!

I also think that in my build there is probably space for a second DDC to run in series. I have reserved a fan header on the Octo for this eventuality.
 
Last edited:

zk2004mb

Average Stuffer
May 23, 2020
58
32
Thanks, current flow rate is 110 to 115 l/h at full speed, 55 l/h at half speed, this is with a 12W DDC.

Getting rid of all air pockets and removing all possible gunk was very important. This contributed to a roughly 25% gain of flow rate in my scenario, and I was using new coolant after running Blitz!!

I also think that in my build there is probably space for a second DDC to run in series. I have reserved a fan header on the Octo for this eventuality.
Just fyi, I have a 280GTS, 2xTX240. With one 18W DDC, I have 0.7GPM at max. To balance the noise I go with two 18w DDC.
Now I have about 1.2GPM at max, 0.45GPM at min, 0.7GPM at quiet level.
Remove some 90 degree fittings will help your flow but with such a complicated loop, it might be too hard to do.
110l/h is about 0.48GPM and it's a bottle neck for your loop on papaer.
 

evadne

Trash Compacter
Original poster
Jan 15, 2020
46
50
Thanks, dual 18W DDC would be ideal if there is space. In order to do that I may have to build a custom PSU which is smaller to yield sufficient space or source a radiator with inlets/outlets on corners like the XSPC TX series in order to properly mount two DDC pumps to it.

An obvious alternative would to use an integrated pump/block combo on the CPU but doing so would mean having to give up the Optimus block, which I think would not be a wise decision

I suspect the main source of restriction actually comes from the quick disconnects, not the 90° fittings. In any case the loop is currently sufficient for my requirements with 10°C delta at full load / 50% pump speed / 50% fan speed. Any further increase in flow rate did not empirically lower the delta… in unscientific testing
 

zk2004mb

Average Stuffer
May 23, 2020
58
32
Thanks, dual 18W DDC would be ideal if there is space. In order to do that I may have to build a custom PSU which is smaller to yield sufficient space or source a radiator with inlets/outlets on corners like the XSPC TX series in order to properly mount two DDC pumps to it.

An obvious alternative would to use an integrated pump/block combo on the CPU but doing so would mean having to give up the Optimus block, which I think would not be a wise decision

I suspect the main source of restriction actually comes from the quick disconnects, not the 90° fittings. In any case the loop is currently sufficient for my requirements with 10°C delta at full load / 50% pump speed / 50% fan speed. Any further increase in flow rate did not empirically lower the delta… in unscientific testing
Your intuition is right. I had two quick-disconnect plugs from barrow and they have even more restrictions together than a 280 rad.
I used apogee drive ii as cpu block, it has one 18W ddc. Then I put a iceman pump reservoir combo at the back of my case with another 18w ddc.
I don't have enough internal space to mount separate ddc pumps.
I had doubt about the iceman reservoir before because I don't want any parts to be outside. But it did save my ass because with the reservoir I can get rid of the quick disconnect. And it also provides you with an extra mount for another ddc.
 
  • Like
Reactions: evadne

Noxonic

Minimal Tinkerer
New User
Jul 14, 2021
3
1
In any case the loop is currently sufficient for my requirements with 10°C delta at full load / 50% pump speed / 50% fan speed. Any further increase in flow rate did not empirically lower the delta… in unscientific testing

Insane build! How much does the system benefit from the third 280GTS? Do you think temps would be much worse by going with only two 280GTS? Which fans did you use and how loud is the system at your 50% speed?

Thanks a lot in advance!
 

evadne

Trash Compacter
Original poster
Jan 15, 2020
46
50
Insane build! How much does the system benefit from the third 280GTS? Do you think temps would be much worse by going with only two 280GTS? Which fans did you use and how loud is the system at your 50% speed?

Thanks a lot in advance!
Hi, I only have 1 280 GTS, and the other 2 (top & bottom) are HWLabs L Series; a proper GTS 280 is too wide, by approximately 1 to 2 mm on each side. Same with SR2.

(If you do want to run dual 280 GTS in SFF, the best bet would be the Winter One which was specifically revised to support that, as far as I know.)

Temperatures are a bit higher without a 3rd radiator. The 1st post has a chart which shows temperatures, that was with only 2 radiators (side and bottom). It is manageable, but with a 3rd radiator I can run the fans slower. Also, with a 3rd radiator I have more liquid so can soak heat for longer.

Currently I have Noctua iPPC-3000 fans, but I am thinking of going back to NF-A14 Chromax Black, since I do not regularly need to run the fans past 2000 rpm. The iPPC fans are absolutely magnificent but they do sound louder when running at low RPM.

This is 100%

Noise wise, it is about 47 db at my seat with the system on the table & idling, 100 cm away. I do have an air purifier running in the background. The system is 52.6 dB at rear vent. Both figures taken with cheap sound level meter. When measured with an Apple Watch it is 45 dB at seat / 50 dB at vent.
 
Last edited:

evadne

Trash Compacter
Original poster
Jan 15, 2020
46
50
Hello, Got a DM asking how much I paid for shipment (China to UK, via Superbuy). Here is what I sent to the learned friend:
Sent via HK UPS
200 USD value declared to customs

Total paid:
1880 CNY freight paid to Superbuy
42 GBP import dues paid to UPS for UK clearance