Log 🚀 Neon Rocket 🦝 - A tiny, powerful, and quiet gaming pc build - 5800X3D + Custom A4000 GPU

[Runamok81]

I need to rewire my fans a bit since I've got a 40mm fan in addition to the 92mm CPU fan on the CPU header connected via a splitter (which sends through only one of the fans' RPM signals). So right now I have no feedback on the 92mm CPU fan RPM values.

So far it seems okay. It is similar to what I observed in the past, which is that using all -30 curve optimizer settings lets CB23 run at 4300mhz while without the PBO2 Tuner setting the curve optimizer settings, CB throttles at 90C with the clock speed at 4100mhz.

I'm running a Velka 7. At 6 liters this is a huge step forward compared to the 10L cases that use 240mm AIOs. I have found that although 240mm AIO is more capable than a 47mm air cooler, the volume efficiency is just not even close.. The 4 extra liters I gain is well worth losing a bit of cooling capacity.

Totally agreed with thoughts on "space efficiency" of air vs water. I feel water is best utilized when it's compensating for poor airflow in the CPU chamber and moving the heat to a place with better airflow.

Cooling the 5800X3D is a challenge. Even folks that have it under water say it has a very "spikey" heat profile. It behaves different. It goes up fast, goes down fast. It's known to have a very small cooling surface area. So, when it's hot it's not "heat soaked" per se. I wish it was, because that is a condition where a water cooler can really shine. On air, I compensate for those spikes by bumping the floor speed of the CPU fans up a little. That keeps the CPU fan from rapidly changing velocity as it annoyingly "chases" those spikes.

For your situation, it sounds like you'll want to rewire those fans. Maybe get them off of the splitter so the CPU fan header can accurately read and set the speed of the primary CPU fan? Getting accurate rpm readings and maybe boosting your fan idle speed should help those idle temps.

 

[AMv8-1day]

Totally agreed with thoughts on "space efficiency" of air vs water. I feel water is best utilized when it's compensating for poor airflow in the CPU chamber and moving the heat to a place with better airflow.

Cooling the 5800X3D is a challenge. Even folks that have it under water say it has a very "spikey" heat profile. It behaves different. It goes up fast, goes down fast. It's known to have a very small cooling surface area. So, when it's hot it's not "heat soaked" per se. I wish it was, because that is a condition where a water cooler can really shine. On air, I compensate for those spikes by bumping the floor speed of the CPU fans up a little. That keeps the CPU fan from rapidly changing velocity as it annoyingly "chases" those spikes.

For your situation, it sounds like you'll want to rewire those fans. Maybe get them off of the splitter so the CPU fan header can accurately read and set the speed of the primary CPU fan? Getting accurate rpm readings and maybe boosting your fan idle speed should help those idle temps.

I've been on the fence about a similar Densium build, and figured the 5800X3D would compliment the A4000 really well from a creative/workstation workload. But if you have to undervolt it so much, just to keep it under control, maybe a 5900 or 5700X might be better...

 

[Runamok81]

I've been on the fence about a similar Densium build, and figured the 5800X3D would compliment the A4000 really well from a creative/workstation workload. But if you have to undervolt it so much, just to keep it under control, maybe a 5900 or 5700X might be better...

Undervolting != underclocking. Quite the opposite. It increases clocks and performance. It also reduces power draw, decrease temps, and lowers noise.
It's something you'll want to do on any AMD 5XXX chip.


If your build goal is workstation performance, then you'll want as many cores as you can keep cool.
That means using a chip with a high core/thread count and a low TDP that didn't exceed the TDP dissipation of your heatsink / cooling solution.
In the Densium, the max cooling capacity for these low profile coolers is about 95W worth of heat dissipation.

This 5800X3D is a 105W part, but the undervolting brings it's watts and temp down within that threshold.
For workstation performance, it's got 8 cores / 16 threads and scored 14.5K in Cinebench R23.

From the chips you mentioned, an undervolted AMD 5900X with 12 cores / 24 threads would do nicely for you. It would score 20.5K or so.
But, if you can flex to team blue, you can get even more workstation performance. Take a look at the Intel T series chips?
The 12900T has 16 cores and 24 threads, and would get you 22.5K in Cinebench.
Intel also recently announced it's 13th gen T series chips which should do even better!

Hope that helps!

 

[Runamok81]

It looks like the A5000 bracket might work for the A2000?

https://www.aliexpress.us/item/3256804353045462.html

 

[density disruptor]

No, it's not two gpus. On top, we have an aftermarket PNY 3060 heatsink and fan only, no card. On the bottom is a full-sized single slot nvidia A4000 workstation gpu. We're going to marry the short heatsink up top to the much longer gpu on bottom.

Let's start by disassembling the A4000 gpu.

Lots of tiny screws to remove ...

With the top plate off, we can see the A4000's heatsink and blower style cooler. The fan on the right forces air left, across the heatsink and out of the case.

Some detail of the A4000 VRMs

Here, we have the A4000 fully disassembled. Notice the tiny pcb? At bottom, is the underside of the aftermarket pny 3060 cooler.

Here is a close up shot of that A4000 pcb. So tiny! For those unfamiliar with the A4000, it is one of nvidia's workstation cards for professionals. It is a binned down 3070Ti with GDDR6 instead of GDDR6X RAM. These workstation cards are typically locked out from overclocking, but we have a special version of MSI Afterburner that has those options unlocked! Even when OC'd the A4000 won't ever reach 3070Ti speeds, due to it's binning and RAM. But it can be faster than an OC'd 3060Ti. And it does that while drawing much less power (-60W) and running much cooler (-14C).

After cleaning off the older thermal paste with pure alcohol, we can apply some fresh paste and install the 3060 cooler.

Viola! Surgery complete. We've now got a DIY ITX PNY A4000!

A shot from the underside. This pcb is so short, even a 3060 cooler overhangs it by an inch or so.

Next, on to some open-bench testing and benchmarks ...

Could you tell me what you did in the area of power connection. Did you have to cut fins
on the heatsink? I am planning on doing this mod with same cooler and gpu. The pig tail
power cable connected to the board is off center from the cut out area on the heatsink.
Thanks and also for the great write up on your build.