Update 2026.10

2× NVIDIA GeForce RTX 5090 PCIe 64GB Configuration to run a model across two devices · Total memory 64GB

2× 32GB GDDR7 VRAM (64GB combined, 3,584 GB/s combined local bandwidth). The RTX 5090 does not support NVLink and communicates only through the PCIe Gen5 interface, resulting in a decrease in parallel efficiency due to an all-reduce communication bottleneck.

Speed and memory for the same model

2× RTX 5090 64GB (PCIe) · Qwen3.8 27B · local LLM speed and memory: Prompt processing · prefill 1,332–2,878 tok/s · Token generation · decode 87.6–135.3 tok/s; Required 17.56GB / Usable 61GB VRAM
4,096 input tokens · single request · prompt cache off

Hardware core specifications

Available memory
61GB
Memory bandwidth
3584GB/s
Estimated sustained LLM load
About 1100W
Korean price range (KRW)
1,798 × KRW 10,000–1,858 × KRW 10,000

Who it fits

  • Utilize 61GB of available memory
  • Two-Device Distributed Inference
  • GLM-5.3-Flash (MoE) model comparison

Skip it if

Even if you connect two devices, the memories are not automatically merged into one. Distributed runtime support and interconnect bottlenecks must be checked together.

Recommended format for each device 4K input

The model you will experience with this equipment

K2 Horizon 0.9B

Required 1.03GB · spare time

llama.cpp CUDA · Q4_K_M · GPU split into 2 pieces

Decode

2637.3 ~ 4070.9 tok/s

First token

0.09 to 0.19 seconds

GLM-5.3-Flash (MoE)

recommended

Required 190.21GB · tight

llama.cpp CUDA · Q4_K_M · GPU split into 2 pieces

Decode

5.1 ~ 5.2 tok/s

First token

3.5 to 7.3 seconds

speed tuning

Actual speed varies with runtime version, cooling, context length and quantization file.

On sales pages, look at memory before chips.

The model and speed assumptions above change if the product is not the 64GB configuration.

Frequently asked questions

What local LLM can be run on 2× RTX 5090 64GB (PCIe)?
K2 Horizon 0.9B, GLM-5.3-Flash (MoE) and others with a 4K input and the recommended format. Required memory varies by model and context length.
What is the power consumption of a local LLM using 2× RTX 5090 64GB (PCIe)?
Sustained load is about 1100 W, with an actual range of 900–1350 W.
Are the displayed token speeds ground truth?
This is a range aligned to collected benchmark measurements under the same conditions. Combinations without a matching measurement are estimated from the nearest result and vary with runtime, cooling, quantization file and context length.