New build - need input on validity

[Martin Moesby]

Budget (including currency): 50.000DKK

Country: Denmark

Games, programs or workloads that it will be used for:  Cyberpunk2077, Private AI - medium sized models, Stable Diffusion, Premier Pro, Unreal Engine

Other details: Upgrading my 12yr old PC 4th gen Intel, 32 GB, Asu7s WS p5x79 mb. (

 

This is NOT a dream build, funding is in order, but I have used Microsft Copilot to come up with the sugggestion and I need smarter gyus than me to validate that the build is sound, so here goes (Yes, I know it is probably a bit overkill, but I am 56 years old, and this will probably be the last PC I build, so I'm going all in)

• 2× NVIDIA RTX 5080 (Inno3d)
• ASUS Pro WS W880‑ACE SE (ATX, dual PCIe 5.0 x16)
• Intel Ultra 9 CPU (285K)
• 96 GB DDR5 (Kingston Fury Beast Black 2×32 + 2x16 CL32)
• 4 TB PCIe 5.0 SSD (Samsung EVO 990 pro)
• 1200W ATX 3.0/3.1 PSU (Asus ROG Strix 1200W Aura edition)
• Antec Flux Pro ATX case
• 360mm AIO CPU‑cooler (Deepcool LE360)

So, the Copolit suggestion also mentioned 2× 12V HPWR GPU cables, and I am not sure what that means? Does the Power supply I have selected not have enough cables to power two gfx cards?

and beyond that question, does anyone see an issue with the components that Copilot didn't? 

 

Kind regards

 

Martin Moesby

 

[BiotechBen]

1 hour ago, Martin Moesby said:

2× NVIDIA RTX 5080 (Inno3d)

Are you going to be doing significant LLM/AI training with it, or just the medium as mentioned? If you aren't going all out on LLM/AI: a single 5090 would likely be better than dual 5080's given the increased VRAM, and will also give better gaming performance. 

(Just a value proposition)

1 hour ago, Martin Moesby said:

96 GB DDR5 (Kingston Fury Beast Black 2×32 + 2x16 CL32)

I would recommend against the mismatched memory unless you got a hell of a deal on it. 

 

2 hours ago, Martin Moesby said:

Does the Power supply I have selected not have enough cables to power two gfx cards?

It only has ONE of the 12VHPWR connectors, you would need adaptors for the others. 

 

2 hours ago, Martin Moesby said:

does anyone see an issue with the components that Copilot didn't? 

Running two 5080 cards at load with the 285k is going to be creeping very close to the 1200W of the PSU, and running it at the very edge of the efficiency curve. Assuming you never transient spikes, you should be fine, but that would be like betting on the NY Jets to win the Superbowl next year. 

I'd honestly go up to a 1600W for the sake of efficiency and safety.

While I HAVE run PSUs at their rates capacity for extended periods: wouldn't really recommend it for the sake of longevity. 

 

Would also point out that the 285K only has 24 PCIE lanes, so if you plan to run your very expensive 5080's at more than gen 5.0 8x: you need a workstation platform with a xeon. 

The board may support bifurcation and running the two slots at 4.0 x16, giving the same total bandwidth as 5.0 x16, but then you'd be potentially leaving performance on the table if you are going to be doing intense workloads with high throughput. 

 

 

 

Wish you luck with your build, just want to make sure you aren't falling prey to the "more is always better" and losing performance per dollar unnecessarily.

[ProtonNeutronElectron]

3 hours ago, Martin Moesby said:

Budget (including currency): 50.000DKK

Country: Denmark

Games, programs or workloads that it will be used for:  Cyberpunk2077, Private AI - medium sized models, Stable Diffusion, Premier Pro, Unreal Engine

Other details: Upgrading my 12yr old PC 4th gen Intel, 32 GB, Asu7s WS p5x79 mb. (

 

This is NOT a dream build, funding is in order, but I have used Microsft Copilot to come up with the sugggestion and I need smarter gyus than me to validate that the build is sound, so here goes (Yes, I know it is probably a bit overkill, but I am 56 years old, and this will probably be the last PC I build, so I'm going all in)

• 2× NVIDIA RTX 5080 (Inno3d)
• ASUS Pro WS W880‑ACE SE (ATX, dual PCIe 5.0 x16)
• Intel Ultra 9 CPU (285K)
• 96 GB DDR5 (Kingston Fury Beast Black 2×32 + 2x16 CL32)
• 4 TB PCIe 5.0 SSD (Samsung EVO 990 pro)
• 1200W ATX 3.0/3.1 PSU (Asus ROG Strix 1200W Aura edition)
• Antec Flux Pro ATX case
• 360mm AIO CPU‑cooler (Deepcool LE360)

So, the Copolit suggestion also mentioned 2× 12V HPWR GPU cables, and I am not sure what that means? Does the Power supply I have selected not have enough cables to power two gfx cards?

and beyond that question, does anyone see an issue with the components that Copilot didn't? 

 

Kind regards

 

Martin Moesby

 

Do you have to go intel? 

[dark_globe]

PCPartPicker Part List

CPU: Intel Core Ultra 9 285K 3.7 GHz 24-Core Processor  (4308.00kr @ Proshop) 
CPU Cooler: Thermalright Grand Vision ARGB 69 CFM Liquid CPU Cooler  (1106.00kr @ Proshop) 
Motherboard: Asus ROG STRIX Z890-H GAMING WIFI ATX LGA1851 Motherboard  (2491.00kr @ Computersalg) 
Memory: Corsair Dominator Titanium 96 GB (2 x 48 GB) DDR5-6400 CL32 Memory  (6373.00kr @ Proshop) 
Storage: Crucial T710 2 TB M.2-2280 PCIe 5.0 X4 NVME Solid State Drive  (2703.00kr @ Computersalg) 
Storage: Samsung 990 Pro 4 TB M.2-2280 PCIe 4.0 X4 NVME Solid State Drive  (4325.00kr @ Alternate) 
Video Card: MSI GAMING TRIO OC GeForce RTX 5090 32 GB Video Card  (24990.00kr @ Proshop) 
Case: Lian Li LANCOOL 217 ATX Mid Tower Case  (978.00kr @ Proshop) 
Power Supply: Corsair HX1200i (2025) 1200 W 80+ Platinum Certified Fully Modular ATX Power Supply  (2021.00kr @ Proshop) 
Total: 49295.00kr
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2026-03-10 09:41 CET+0100

[Martin Moesby]

4 hours ago, dark_globe said:

PCPartPicker Part List

CPU: Intel Core Ultra 9 285K 3.7 GHz 24-Core Processor  (4308.00kr @ Proshop) 
CPU Cooler: Thermalright Grand Vision ARGB 69 CFM Liquid CPU Cooler  (1106.00kr @ Proshop) 
Motherboard: Asus ROG STRIX Z890-H GAMING WIFI ATX LGA1851 Motherboard  (2491.00kr @ Computersalg) 
Memory: Corsair Dominator Titanium 96 GB (2 x 48 GB) DDR5-6400 CL32 Memory  (6373.00kr @ Proshop) 
Storage: Crucial T710 2 TB M.2-2280 PCIe 5.0 X4 NVME Solid State Drive  (2703.00kr @ Computersalg) 
Storage: Samsung 990 Pro 4 TB M.2-2280 PCIe 4.0 X4 NVME Solid State Drive  (4325.00kr @ Alternate) 
Video Card: MSI GAMING TRIO OC GeForce RTX 5090 32 GB Video Card  (24990.00kr @ Proshop) 
Case: Lian Li LANCOOL 217 ATX Mid Tower Case  (978.00kr @ Proshop) 
Power Supply: Corsair HX1200i (2025) 1200 W 80+ Platinum Certified Fully Modular ATX Power Supply  (2021.00kr @ Proshop) 
Total: 49295.00kr
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2026-03-10 09:41 CET+0100

Hey, Thank you for the input, and this was maybe the other way to go, with a single 5090 and then I wopuld be able to use the 1200w PSU...

 

Thanks

[Martin Moesby]

11 hours ago, a350xwb-pc said:

Do you have to go intel? 

I dont really know - I have always gone the Intel route, I guess - do you have any sugggestions on an AMD route? 

[Martin Moesby]

12 hours ago, BiotechBen said:

Are you going to be doing significant LLM/AI training with it, or just the medium as mentioned? If you aren't going all out on LLM/AI: a single 5090 would likely be better than dual 5080's given the increased VRAM, and will also give better gaming performance. 

(Just a value proposition)

I would recommend against the mismatched memory unless you got a hell of a deal on it. 

 

It only has ONE of the 12VHPWR connectors, you would need adaptors for the others. 

 

Running two 5080 cards at load with the 285k is going to be creeping very close to the 1200W of the PSU, and running it at the very edge of the efficiency curve. Assuming you never transient spikes, you should be fine, but that would be like betting on the NY Jets to win the Superbowl next year. 

I'd honestly go up to a 1600W for the sake of efficiency and safety.

While I HAVE run PSUs at their rates capacity for extended periods: wouldn't really recommend it for the sake of longevity. 

 

Would also point out that the 285K only has 24 PCIE lanes, so if you plan to run your very expensive 5080's at more than gen 5.0 8x: you need a workstation platform with a xeon. 

The board may support bifurcation and running the two slots at 4.0 x16, giving the same total bandwidth as 5.0 x16, but then you'd be potentially leaving performance on the table if you are going to be doing intense workloads with high throughput. 

 

 

 

Wish you luck with your build, just want to make sure you aren't falling prey to the "more is always better" and losing performance per dollar unnecessarily.

Thank you so much for your input

 

 

My wish for this would be to do some LLM and Lora training - and some Stable Diffusion, which in my understanding benefits quite good on multiple GPUS ?

 

Gaming for me is just a Bonus - I do not run the latests games, Cyberpunk is my choice at the moment, Horizon Zero Dawn and Tombraider - sp not the Multiplayer actions games.

Unreal Engine for game development and Adobe for photo/video editing...

 

I've also come to term with the 1600w PSU is the way to go, apparently Copilot does not know the correct requiorements of 5080's...

Another way could be to use a single 5080 and the add a second Pro Blackwell card instead?

 

I'm am not into overclocking or tuning or anything else - I just want to put it togehter and see it work. Will it be an issue for the two cards with the PCIe Lanes? What CPU should I choose otherwise? 

 

KInd regards

 

Martin

[ProtonNeutronElectron]

15 hours ago, Martin Moesby said:

I dont really know - I have always gone the Intel route, I guess - do you have any sugggestions on an AMD route? 

If you have that budget a ryzen 9 9950 x3d will give you better performance.

[igormp]

On 3/10/2026 at 10:09 AM, Martin Moesby said:

I dont really know - I have always gone the Intel route, I guess - do you have any sugggestions on an AMD route? 

I personally have a 9950x, it has AVX-512 so for some stuff it ends up being faster than ARL. AM5 also has more options when it comes to mobos with x8/x8 GPU support that may be cheaper in your region (I have a x670e ProArt with 2x3090s on a 1000W PSU), and it also would allow you to upgrade to Zen 6 whenever that launches.

On the other hand, ARL has CUDIMM support and that should allow you to go with 128GB+ of RAM running at higher clocks easier. Getting 5600MHz with my 4x64GB kit was a bit annoying and required lots of BIOS upgrades, wheres with ARL it should work almost out of the box on a similar config.

 

I would go with what ends up being the cheaper combo.

On 3/10/2026 at 10:28 AM, Martin Moesby said:

My wish for this would be to do some LLM and Lora training - and some Stable Diffusion, which in my understanding benefits quite good on multiple GPUS ?

A single 5090s may be cheaper than 2x5080s, provide the same amount of VRAM and be faster overall. That stuff does benefit from multiple GPUs, but only if both GPUs give you more VRAM or end up being faster than a single one, which is not the case of a 5090 vs 2x5080. It'd make way more sense if you were doing 2x5090.

On 3/10/2026 at 10:28 AM, Martin Moesby said:

Gaming for me is just a Bonus - I do not run the latests games, Cyberpunk is my choice at the moment, Horizon Zero Dawn and Tombraider - sp not the Multiplayer actions games.

9950x3D if you want to splurge the cash, otherwise the regular 9950x oughta do just fine.

On 3/10/2026 at 10:28 AM, Martin Moesby said:

I've also come to term with the 1600w PSU is the way to go, apparently Copilot does not know the correct requiorements of 5080's...

I use my 2x3090s with a 9950x on a 1000W PSU. You just need to know how to properly set power limits and whatnot. AFAIK most 5080s do 360W by default. 2x of those would be 720W, ARL/Zen 9 should not get even close to 300W, so you'd be reaching 1000W tops, 1200W is pretty safe. If you power limit the GPUs to 300W you'd be even safer and I bet you wouldn't notice the performance difference.

If you were doing dual 5090s then you'd pretty much need to set proper power limits.

On 3/10/2026 at 10:28 AM, Martin Moesby said:

Another way could be to use a single 5080 and the add a second Pro Blackwell card instead?

Why not just a single Pro Blackwell if you can afford such?

On 3/10/2026 at 10:28 AM, Martin Moesby said:

I'm am not into overclocking or tuning or anything else - I just want to put it togehter and see it work. Will it be an issue for the two cards with the PCIe Lanes? What CPU should I choose otherwise? 

Not sure how it'd go on Windows, but on Linux it'd work pretty much out of the box.

[Martin Moesby]

OK, I fínally settled on a system - I went all out on the ProArt-line:

Asus Proart :

• PS602 Walnut Wood Case,
• LC 420 Cooler,
• Z890CREATOR-WIFI Motherboard
• RTX 5070TI OC x 2 GFX

Intel Core Ultra 7 265K

64GB  Crucial Pro

2TB Samsung 9100 PRO

2TB Samsung 990 PRO

be Quiet Dark Power Pro 1600W
 

I know, its a trade off on the GFX's, but the VRAM is the same, the OC cranks it to around 2680 clock speed - and the 15% performance gain on the RTX 5080 contra the  RTX 5070TI is, in my book, NOT worth the 30-35% increase in price - and the proicetag for a single RTX 5090 was just to much, so a tradeoff for a cleaner Proart Build and smaller CPU and a 200$ savings on the price...fine by me!

 

But the build is a real smooth, clean build, real quiet.. with just a few light accents from the GFX and the cooler inside the case...

 

Thank you all for your inputs - they were much appreciated and all taken into consideration.

 

/Martin