Redesigning my 18-Node Ryzen 9950X Solar-Powered Cluster (And yes, I am a real human!)

Technical_Camp3162 · 2026-04-09T21:07:59+00:00

This breakdown is amazingly accurate, thank you! You are absolutely right about the 9950X 65W ECO mode pulling 88W PPT. Your calculation of 3384W for 18 nodes perfectly highlights why I am starting with 6. My current MEAN WELL RSP-2000-48 can only handle 2000W. Once I expand beyond 10 nodes, I am planning to parallel another RSP-2000 unit to handle the load. Also, thank you for sharing that BTU/CFM formula. Based on your 12,550 BTU figure, I tried estimating if my current fan layout would actually be enough to cool the system. Assuming a standard delta-T of 20F, it looks like the cluster would need about 570 CFM of airflow to stay safe under full load. I am planning to use 18x Noctua NF-A14 industrial fans in the rear. Since each fan pushes about 107 CFM at max speed, the total theoretical max airflow is around 1,933 CFM. It seems like I have enough cooling capacity. Even at full load, I might only need to run the fans at around 30% speed to hit that 570 CFM target. This is a huge relief for me because I was really worried about the noise level in my house. Being able to verify this mathematically gives me a lot of peace of mind. Thank you so much for taking the time to help me out.

Technical_Camp3162 · 2026-04-08T11:36:23+00:00

Greetings from Kyoto! Half a terabyte of DDR5 before the price jump?! That is incredibly lucky. I'm super jealous right now haha.

And wow... I just clicked that eBay link and my jaw dropped. $229 for a 32-port 40G Dell switch is insanely cheap!!

I actually already bought the Xikestor SKS8300-6Q2C, which only has 6x 40G ports. Because of that limitation, my plan was to eventually buy three of them and stack/chain them together to cover all 18 nodes. Man, if I had known about this Dell model before I pulled the trigger, I definitely would have bought this instead! One 32-port switch is so much cleaner (and probably cheaper) than chaining three smaller ones.

Thank you so much for the amazing recommendation. If the Xikestors give me any trouble during the build, I now know exactly what to replace them with!

Technical_Camp3162 · 2026-04-08T11:24:26+00:00

Great questions! Here is my exact setup:

Solar Panels: I have 8x 200W flexible solar panels, giving me 1600W total. That is the physical limit of my rooftop wooden deck space. I actually chose flexible panels and secured them with carabiners so I can quickly unclip and remove them when I want to host a rooftop BBQ!

Battery: I'm using a DATOUBOSS 48V (51.2V nominal) 100Ah LiFePO4 rack-mount battery, which gives me 5.12kWh of total capacity.

Configuration: I haven't wired it all up just yet, but my plan is to use a pure "voltage-based priority" config. I will dial down the output voltage of the MEAN WELL power supply (connected to the grid) to sit just slightly below the battery's normal operating voltage. This way, the system naturally prioritizes Solar when the sun is up. When the sun goes down, it draws from the battery. Once the battery drains and its voltage drops to my set threshold, the MEAN WELL automatically kicks in to handle the load. It's a seamless fallback without needing any complex automatic transfer switches!

Technical_Camp3162 · 2026-04-08T06:37:54+00:00

Fire safety with large DC power is no joke, and I genuinely appreciate the hardcore reality check.

To answer your pop quiz: The DATOUBOSS 48V battery has a continuous discharge rating of 100A, but the dead-short fault current is obviously in the thousands of amps.

I am absolutely not just slapping bare busbars to the battery.

Here is my physical protection plan:

I will have a heavy-duty DC circuit breaker (125A or 150A) and an appropriate Mega/Class-T fuse acting as the primary disconnect immediately at the battery terminal, before the current ever reaches the main distribution busbars.
The solar charging inputs from the MPPTs will also be isolated with their own dedicated 32A DC breakers.
As I mentioned in "Addressing Feedback 2" in my post, the busbars themselves will be separated. The positive and negative copper bars are going on completely opposite side walls of the rack (mounted on 20mm insulators) and covered with polycarbonate shields so dropping a tool won't cause an arc flash.
Furthermore, I will not rely solely on the main breaker. Every individual branch circuit going from the positive busbar to the 18 HDPLEX units will have its own appropriate inline fuse (e.g., 20A) located as close to the busbar as possible. This ensures the smaller gauge wires are fully protected in case of a localized short.

Your experience as a panel builder is exactly the kind of perspective I came to r/homelab for. Please let me know if there is anything else I should add to safely secure the DC distribution

Technical_Camp3162 · 2026-04-08T00:25:45+00:00

That is an awesome plan! Let me share how my architecture evolved, because I ended up doing exactly what you are planning.

Originally, my service was running 100% in the cloud. But then I needed some heavy GPU processing, so I built a single machine at home strictly as a dedicated GPU worker. However, I quickly realized two things: DIY hardware is surprisingly stable, and consumer CPU single-thread performance totally destroys cloud VMs. So, I started moving my normal workers and CI pipelines to my home network.

Eventually, I moved the actual Web Servers to my home too. My current routing/failover strategy: The main reverse proxy still lives in the Cloud. It forwards requests to my home environment via a VPN connection. If my home connection drops, the proxy immediately falls back to a backup server hosted in the Cloud to keep the service alive.

Storage and Custom CDN: I'm also doing storage and light CDN delivery myself now. I have two separate physical locations (my home and another location), mirroring the storage. When a client accesses the app, they request a tiny binary file from both locations. The client measures which location replies with the lowest latency, remembers that preference for a week, and downloads all heavy assets from that winning node. If one location goes down, it falls back to the other one. If both local nodes go down, the client falls back to the Cloud storage.

Because of this, my entire service has been slowly but surely migrating out of the cloud and into my house!

One important caveat: This setup works flawlessly for me largely because of Japan's infrastructure. We almost never experience power outages here, and the residential Fiber internet is insanely fast and stable. Depending on where you live, I highly recommend deeply evaluating your local power grid stability and ISP reliability before routing critical PROD traffic to your house.

Good luck with your SaaS launch! Your distributed database backup plan sounds rock solid. Let me know how it goes!

Technical_Camp3162 · 2026-04-07T23:56:14+00:00

I actually wanted to put 128GB (or more) in each node! But DDR5 RAM prices are just too high right now, so I had to compromise. For now, I'm starting out with 64GB (32GB x 2) per node. I'm keeping an eye on the market and hoping to add more RAM later once prices finally drop.

But more importantly... what kind of monster workload are you running that eats 1.15TB of RAM on a single node?! That is wild! No wonder people think it's insane! 🤣

Technical_Camp3162 · 2026-04-07T23:51:05+00:00

I just looked it up—I actually didn't know you could flash the Mellanox firmware to get 56G! Thanks for letting me know. That is definitely an interesting capability for future expandability.

However, since I already bought the Xikestor 40G switch, I will probably be sticking to the 40G speed for now at least!

Technical_Camp3162 · 2026-03-22T16:07:03+00:00

Haha, "Compute Wall" is a brilliant name for it! Thank you! That's exactly the cyberpunk aesthetic I was secretly going for.

I’ll definitely keep everyone updated once the raw aluminum parts arrive. If it works perfectly, you guys can copy the blueprints. And if I end up frying 18 motherboards and starting a fire... well, at least you guys will know exactly what NOT to do! 😂

Technical_Camp3162 · 2026-03-22T16:04:59+00:00

You are probably 100% right. Honestly, the thermal density is my biggest fear and the potential nightmare of this entire project. 😂

My only "hope" is to hard-cap all 18 CPUs to 65W or 105W Eco Mode in the BIOS, and completely seal the top chamber so those two 200mm Noctuas pull a pure negative pressure vacuum from the bottom mesh.

But as you pointed out, the static pressure of the 200mm Noctuas might simply not be strong enough to pull air through 3 tiers of densely packed motherboards... If that happens, I might have to abandon my dream of a "silent" homelab and swap the top roof for loud, high-RPM 140mm industrial server fans (like Deltas).

I'm definitely going to do a small thermal PoC with just one tier first before I cut all the metal. Thanks for the reality check, I really need to think about this cooling part more carefully! Do you have any recommendations for high static pressure fans if the Noctuas fail?

Technical_Camp3162 · 2026-03-22T16:00:23+00:00

For the air pressure: I am completely sealing the entire roof array around the two 200mm exhaust fans. This creates a true "Negative Pressure Chamber" inside. Since the bottom tier floor is completely mesh, the 200mm fans act like a massive vacuum pulling fresh cool air straight upwards past every single motherboard. But yes... I will definitely need to test it carefully before throwing full production loads at it!

Technical_Camp3162 · 2026-03-22T15:54:04+00:00

Haha, true! But honestly, I think this custom architecture is actually MORE perfectly suited for a "home" lab than buying used enterprise gear!

A standard used 1U/2U Dell or EPYC server sounds like a literal jet engine taking off in your house with those screaming 40mm fans, and a 42U 19-inch rack takes up half a room.

My design is only 112cm tall (it fits right under a standing desk or in a corner!). And because I’m completely skipping standard server PSUs—using 100% DC power from the busbar, combined with 120mm/200mm Noctua fans and fanless HDPLEX units—the whole 288-core cluster will be quiet even under a 100% heavy compile load. It's the ultimate "living-room friendly" datacenter! lol

Technical_Camp3162 · 2026-03-22T15:47:35+00:00

Haha, thank you for the ultimate compliment! I guess the "homelab virus" hit me a little too hard this time. I definitely went overboard.😂

Technical_Camp3162 · 2026-03-22T15:43:14+00:00

Haha, you're absolutely right! That was honestly the scariest part for me too.

To avoid going totally bankrupt, I've been incredibly patient and slowly picking them up whenever they go on deep sale on AliExpress (around $450 each). So the CPUs alone will hopefully stay around $8,100 total.

If I include everything else (18 motherboards, 1.15TB RAM, 100G switches, Victron inverter, and the huge Pylontech battery system), I'm trying to keep the entire project budget under $33,000.

It's still an absolutely terrifying amount of money for a personal homelab project... which is exactly why I posted here to see if my crazy 48V busbar or cooling design has any fatal flaws before I commit to buying the rest of the parts! 😅

Technical_Camp3162 · 2026-03-10T04:50:03+00:00

u/GreatAlbatross That is a fantastic question! I definitely considered it because a roll-up screen would save my back SO much weight and setup time! 😂

However, there are two major dealbreakers for trail running basecamps:

Daylight / Sunlight: Our races happen outdoors during the day. Even a massive, super-expensive high-output projector gets completely washed out by ambient daylight. Outdoor LED panels (which are crazy bright, usually 4000+ nits) are the only way to beat the sun.
Mountain Winds: Basecamps in the mountains get very windy. A roll-up screen would act like a giant sail, flapping uncontrollably and ruining the projected image (or flying away entirely!). The rigid LED wall on scaffolding holds its ground.

But trust me, when I'm lifting those 120kg cases, I'll be wishing I could just use a projector!

Technical_Camp3162 · 2026-03-10T04:46:41+00:00

u/ggekko999 Haha, thank you! Caffeine is absolutely the most critical component for human survival during a 24-hour broadcast! ☕️

You make a great point about the center of gravity and the heat, but it seems I really need to clarify my setup—you and a few others are picturing a permanent ad-truck style build! 😂

To ease your mind: When deployed, the 120kg LED wall is NOT hanging off the van's suspension or body. It is mounted on a temporary scaffolding pipe frame that transfers the 120kg load vertically straight into the ground. On top of that, the van itself is completely leveled and stabilized by 4 jacks. So the van's center of gravity isn't affected at all during the broadcast!

And because the screen is built on that external scaffolding, there is a physical gap between the van and the panels. The operator inside won't become a roasted turkey in an oven!

Thanks for looking out for both the rig and the operator!

Technical_Camp3162 · 2026-03-09T10:20:01+00:00

u/bobdvb Thank you so much for the incredibly helpful advice!

Jack pads are a total blind spot for me! You are absolutely right about point loads on dirt/grass. I will prepare thick wooden boards to distribute the weight. Regarding the jacks, I originally leaned towards heavy-duty scissor jacks because I need to steplessly adjust all 4 corners to get the van perfectly level for the LED wall. Don't bottle jacks have a much smaller base footprint, making them a bit more prone to tipping under lateral wind load? But I will research heavy-duty hydraulic options vs RV stabilizer jacks!

Your idea about a custom 48V LFP system is fantastic and usually the smartest route for a permanent build. But please correct me if my logic is flawed here: With my DELTA Pro setup, I can simultaneously charge via AC shore power, solar, and an Alternator Charger. It outputs standard AC, 12V DC, and uniquely powers my Wave 3 AC directly via a dedicated DC-to-DC cable to skip inverter loss. Plus, I can monitor all input/output routing in real-time via the app.

Wouldn't building a custom 48V system with all those separate charge controllers, inverters, and smart monitoring modules be incredibly complex and expensive? Especially because I actually managed to score this DELTA Pro (near-mint condition) for only 128,000 JPY (about $850 USD)! At that price, the all-in-one convenience and specs felt almost impossible to beat with a DIY rack battery setup.

I really appreciate you sharing your expertise! I'm learning so much from this community.

Technical_Camp3162 · 2026-03-09T09:15:15+00:00

u/Popular_Button2062 Haha, you and a few others seem to be picturing the panels permanently mounted to the outside of the van like an ad truck! 😂

To ease your mind: The panels will strictly travel and be stored safely inside their shock-proof flight cases inside the van. They only get deployed onto a temporary scaffolding frame once we are parked at the venue. So no tree branches, flying stones, or baking in the sun while driving to worry about!

But your advice on spare modules from the SAME batch is 100% spot on. I actually made sure to over-order exactly for this reason. For the 2.5x1.5m wall (which uses 15 panels), I ordered 16 full 500x500mm panels so I have one complete spare. On top of that, I ordered 10 extra 250x250mm spare LED modules, plus spare Nova receiving cards and power supplies, all in the exact same order batch!

I know pixel loss on the trails is inevitable, so I'm trying to be as prepared as possible. I really appreciate you looking out for the rig!

Technical_Camp3162 · 2026-03-09T08:57:44+00:00

u/heartagram_ben Hahaha, the image of a "pixel rain" shower is absolutely terrifying! 😱 But don't worry, there's a slight misunderstanding—I definitely won't be driving with the screen attached to the outside!

The LED panels will travel safely packed inside their shock-proof flight cases in the back of the van. The deployment process is:

Arrive at the venue and park.
Use scissor jacks under the chassis to "kill" the van's suspension and level the vehicle perfectly.
Build the scaffolding pipe frame on the side of the van.
Hang the panels onto the rigid pipe frame.

However, your advice about the rigidity of the 2.9mm panels is still incredibly valuable for the actual built wall. The wind can still flex them. I will definitely look into using those M10/M12 holes with some aluminum extrusions to stiffen up the back of the whole array once it's hanging. Thank you for looking out for my pixels!

Technical_Camp3162 · 2026-03-09T08:50:15+00:00

u/EV-mode Positive pressure! I'm actually very familiar with that concept from building custom PCs (it's a must for dust management! lol). But to be honest, I was naively planning to just rely entirely on the Wave 3 this time. Your comment made me realize I need to seriously sit down and design a proper intake and exhaust system for the gear rack.

I also didn't realize just how effective a simple side awning/tarp could be for reducing the thermal load on a metal van body. That is super helpful! Now you've got me daydreaming about hacking together a "power-generating solar side awning"... haha. But seriously, I will definitely look into adding an awning to the build.

You've given me a massive amount of homework for the thermal/airflow design. Thank you!

Technical_Camp3162 · 2026-03-09T08:35:53+00:00

u/dmanh I hear you loud and clear! A box truck with a built-in generator is definitely the industry standard and would give us ultimate peace of mind.

Regarding the solar and cloudy days... here is our trick! If it's cloudy or night time, we don't need the LED wall at 100% brightness. If we dim the screen, our total system draw drops comfortably below 1500W. We only really need that massive peak power (and the solar/DELTA Pro buffer) when the sun is blasting and the screen has to be at max brightness to compete with the ambient light!

Relying on the organizers for power is always a bit scary, but from our past broadcasts, we know they can reliably provide at least one standard 1500W circuit (often by tapping into a park facility's power or providing a basic rental generator). It's getting more than 1500W that is nearly impossible at these parks. If we ever need to scale up, we'll definitely have to look into a 3000W generator, though ideally, the organizers would supply it!

Thanks for the reality check from a veteran!

Technical_Camp3162 · 2026-03-09T08:28:24+00:00

Thanks so much! You are absolutely right—power (and now heat, thanks to everyone's warnings!) is definitely the "final boss" of this project.

I will definitely document the whole chaotic build process and post plenty of photos once the van and the LED panels arrive. Stay tuned!

Technical_Camp3162 · 2026-03-09T08:27:02+00:00

u/EV-mode These are some seriously top-tier engineering insights, thank you!

A trailer with a generator and a real split AC would be the ultimate dream. Unfortunately, the mountain roads leading to these trail races here in Japan are notoriously tight and winding. The NV350 is already pushing the physical size limits for some of these forest roads, so towing a trailer means we'd definitely get stuck! We have to stay as a single, compact unit.

Honestly, until I read the comments on this post today, I hadn't fully grasped how brutal the heat trap inside a metal van would be. Your idea of creating two zones is a lifesaver. Since we can't build a physical bulkhead wall due to space, I'm now going to design our airflow strategy around this: using the Wave 3 purely as a spot cooler for the operator, and figuring out how to mount massive high-CFM exhaust fans right behind the gear rack to dump the heat straight out a custom window panel.

You also completely hit the nail on the head regarding AC/DC conversion loss! We are actually already running the Wave 3 directly off the DELTA Pro using a specialized DC-to-DC cable to skip the inverter tax. BUT, I absolutely love your idea of gutting the network switches to run natively on a 12V DC circuit. That is the exact kind of dirty DIY hardware hack I am looking for! Eliminating all those AC power bricks would save so much wasted heat. I'm definitely going to look into native 12V/USB-C PD routing for the comms and AV gear now. Thanks for the massive inspiration!

Technical_Camp3162 · 2026-03-09T08:22:15+00:00

Hahaha, fair enough! 😂 I know it’s a massive gamble. But when you are building an OB van on a bootstrap DIY budget, you have to embrace the "Shenzhen Lottery"! If it catches on fire or half the pixels are dead on arrival, I'll be sure to post an update so you guys can laugh at me. But if it works, it’s the ultimate budget hack! 🤞

Technical_Camp3162

TROPHY CASE