8B to 14B: ample headroom
Multiple small components, longer contexts, or parallel tasks become more realistic as long as the runtime uses memory efficiently.
GPU guide for fast local AI
RTX 5090 complete systems for local LLMs
With 32 GB of GDDR7 and high memory bandwidth, the GeForce RTX 5090 is a fast single GPU for local inference. It is strongest when the model, context, and runtime fit fully in VRAM.
Workload fit
What 32 GB of VRAM handles well
20B to 32B: the sweet spot
Suitable quantizations can remain fully in VRAM. This is the compelling tier for fast coding assistants, RAG, and more capable local chat.
70B: expect a compromise
A typical 70B model does not fit comfortably in 32 GB together with context, even at strong quantization. Partial system-RAM offload reduces speed.
NVIDIA specifies 32 GB of GDDR7 for the desktop RTX 5090. Model architecture, quantization, and KV cache decide what fits in practice.
Two complete systems
Same GPU capacity, different system priorities
Both configurations target fast 8B-to-32B inference. Compare storage, chassis, cooling, and exact model identity instead of treating every RTX 5090 tower as equal.
64 GB RAM · 6 TB storage
Corsair Vengeance i8300
A high-end tower with substantial local model storage and a two-module memory layout.
Choose it for
The 2 TB + 4 TB NVMe layout can hold several model families and project data. Its 64 GB arrives as 2×32 GB, while 5GbE and Wi-Fi 7 are useful when the PC serves models to other devices.
Know before buying
The RTX 5090 still limits fully GPU-resident workloads to 32 GB. Confirm exact model CS-9060020-NA; similarly named Vengeance systems can contain different storage or GPUs. Check the motherboard's free slots and supported maximum before planning a RAM upgrade.
- CPU / GPU
- Core Ultra 9 285K / RTX 5090 32 GB
- RAM
- 64 GB DDR5 (2×32 GB)
- Storage
- 2 TB + 4 TB NVMe
- Cooling
- 360 mm CPU liquid cooler
- Power
- 1200 W 80+ Gold
- Network
- 5GbE, Wi-Fi 7
64 GB RAM · expandable tower
HP OMEN 45L GT22-3090
A roomy RTX 5090 tower with Thunderbolt 4 and support for up to 128 GB of system memory.
Choose it for
The large chassis, 1200 W Gold power supply, Thunderbolt 4, and 2.5GbE suit a workstation-style desk setup with external storage or network clients.
Know before buying
The included 64 GB uses 4×16 GB and therefore occupies every DIMM slot; reaching 128 GB requires replacing the installed modules. Confirm GT22-3090 / B91WJAA#ABA and the 2 TB SSD.
- CPU / GPU
- Core Ultra 9 285K / RTX 5090 32 GB
- RAM
- 64 GB DDR5-5600 (4×16 GB); up to 128 GB
- Storage
- 2 TB PCIe 4.0 NVMe
- Power
- 1200 W 80+ Gold
- Network
- 2.5GbE, Wi-Fi 6E
- Fast I/O
- Thunderbolt 4 / USB-C 40 Gbps
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Balanced specification
What a complete RTX 5090 PC should include
| Component | Useful starting point | Why it matters |
|---|---|---|
| GPU | desktop GeForce RTX 5090, 32 GB | mobile or differently named variants are not equivalent |
| System RAM | 64 GB; 128 GB for frequent offload | runtime, RAG data, and offloaded layers need headroom |
| SSD | at least 2 TB NVMe | models and multiple quantizations consume space quickly |
| Power | vendor-engineered for sustained load | GPU, CPU, and transient loads must be covered together |
| Cooling | large airflow chassis with clear intake/exhaust | long inference sessions are sustained workloads |
| Networking | 2.5 GbE is useful | practical when serving models to other devices |
Configuration, not family name
Check these six details before buying
Desktop GPU and 32 GB stated explicitly
The exact offer must name the RTX 5090 and its memory. A configurable product family is not proof of the linked configuration.
RAM layout and open slots
64 GB is a sensible start. Check module count, speed, and whether later expansion requires replacing every DIMM.
SSD layout and open M.2 slots
A second SSD can separate models and project data from the operating system. Open slots simplify upgrades.
Power supply and GPU cabling
Power rating, quality tier, and correct GPU cabling should be part of the vendor configuration.
Chassis and service access
Filters, fan positions, and accessible components matter more to a long-lived local AI machine than decorative lighting.
Do not infer 70B capacity from GPU speed
If 70B without substantial CPU offload is your main goal, compare 128 GB unified memory or professional GPUs with 48 to 96 GB of VRAM.
Corsair or HP?
Choose storage and upgrades deliberately
Pick the Corsair i8300 if 6 TB of included NVMe storage, 5GbE, and two-module RAM matter most. Pick the HP OMEN 45L if you prefer its larger chassis and Thunderbolt 4, but budget for extra model storage and a complete DIMM replacement if you want 128 GB.
Need 70B capacity?
Memory before raw compute
A fast CPU and RTX 5090 do not remove the 32 GB limit. Compare three realistic memory paths for 70B models.
Compare 70B PCs