Stable Diffusion 1.5 · 28 GPUs measured first-party · text-to-image · Updated October 2026

What GPU Do You Need for Stable Diffusion 1.5?

We ran Stable Diffusion 1.5 at 512px on 28 GPUs, from budget cards to datacenter parts, and measured image speed, power draw and peak VRAM on every one. The fastest was NVIDIA GeForce RTX 5090 at 102.4 images/min.

Benchmarked weights: stable-diffusion-v1-5/stable-diffusion-v1-5

Fastest we measured

NVIDIA GeForce RTX 5090

102.4 images/min on Stable Diffusion 1.5, the ceiling. Measured on our bench. 32GB of VRAM, $1,999 at launch.

Pros

• 102.4 images/min on Stable Diffusion 1.5
• 32GB, clears the Stable Diffusion 1.5 floor

Cons

• 575W board rating

Best consumer card

NVIDIA GeForce RTX 4090

80.14 images/min on Stable Diffusion 1.5, fastest card you can buy at retail. Measured on our bench. 24GB of VRAM, $1,599 at launch.

Pros

• 80.14 images/min on Stable Diffusion 1.5
• 24GB, clears the Stable Diffusion 1.5 floor

Cons

• 450W board rating

Cheapest card that runs it

NVIDIA GeForce RTX 5060

23.9 images/min on Stable Diffusion 1.5, lowest launch price that still fits. Measured on our bench. 8GB of VRAM, $249 at launch.

Pros

• 23.9 images/min on Stable Diffusion 1.5
• 8GB, clears the Stable Diffusion 1.5 floor

Cons

• 145W board rating

Best value

GeForce RTX 5070

39.2 images/min on Stable Diffusion 1.5, most speed per dollar. Measured on our bench. 12GB of VRAM, $549 at launch. That is 71.4 images/min per $1,000 of launch price.

Pros

• 39.2 images/min on Stable Diffusion 1.5
• 12GB, clears the Stable Diffusion 1.5 floor

Cons

• 250W board rating

What the numbers show. Across 27 GPUs measured on our own bench, RTX 5090 is fastest at 102 images/min. L4 is the most efficient, 28.6 images/min at 72W (0.397 images/min per watt). Per dollar of launch price, RTX 5060 Ti gives the most (76.4 images/min per $1,000). The fastest card with 16GB or less is RTX 5080 at 61.2 images/min. The measured peak was ~5GB, so it runs on 6GB cards and up. That floor is a property of the model, so it applies to every GPU, measured or not.

About Stable Diffusion 1.5. Stable Diffusion 1.5: from Lykon, 0.9B parameters, on Hugging Face since August 2023, creativeml-openrail-m licence. 67,836 downloads in the last 30 days.

How it compares. L40S: Stable Diffusion 1.5 58.54 images/min, PixArt-Sigma XL 26.95, Stable Diffusion 3.5 Medium 11.58 (2B), Playground v2.5 10.85 (3B), SDXL Turbo 423.5 (3B). 1 of 4 beat Stable Diffusion 1.5 here.

Cost on a rented GPU. 1,000 images of Stable Diffusion 1.5: $0.038 on a RTX 3060 ($0.036/hr, 63 min), $0.063 on a RTX 5090 ($0.39/hr, 10 min, 1.7x the cost).

Speed tiers for Stable Diffusion 1.5. 30+ images/min: 18 (RTX 5090, RTX 4090, RTX 5080); 6-30 images/min: 10 (RTX 3070 Ti, RTX 4060 Ti 16GB, RTX 3070 Founders Edition). 30 images/min means two seconds or less per picture.

Time per image. Stable Diffusion 1.5 at 512px and 30 steps: 0.6s per image on the RTX 5090, 3.8s on the RTX 3060. A batch of 100 takes 1 min on the fastest card and 6 min on the slowest.

VRAM for Stable Diffusion 1.5. Measured peak 3.9GB, so 8GB is the smallest common card size; smallest card it ran on: RTX 3070 Ti (8GB).

Power on Stable Diffusion 1.5. Most efficient: L4, 72W, 42.0 Wh per 1,000 images. Hungriest: RTX 5090, 451W, 73.4 Wh.

Our verdict

Fastest on Stable Diffusion 1.5: NVIDIA GeForce RTX 5090, 102.4 images/min. Cheapest consumer card that ran it: NVIDIA GeForce RTX 5060 ($249, 23.9 images/min). Cheapest to rent per job: NVIDIA GeForce RTX 3060, $0.038 per 1,000 images.

FAQ

What GPU do I need to run Stable Diffusion 1.5?

About 4GB. Cheapest consumer card that ran it: NVIDIA GeForce RTX 5060 (8GB, 23.9 images/min).

How fast is Stable Diffusion 1.5 on the NVIDIA GeForce RTX 5090?

102.4 images/min at 451W, faster than every datacenter card we ran it on.

How much does it cost to run Stable Diffusion 1.5 in the cloud?

$0.038 per 1,000 images on a NVIDIA GeForce RTX 3060 at $0.036/hr, cheapest of 23 rentable cards we measured.

Can I run Stable Diffusion 1.5 on a 12GB, 16GB or 24GB card?

It used 3.9GB at the precision we tested. 12GB: yes; 16GB: yes; 24GB: yes.

Is the RTX 4090 or the RTX 3090 faster for Stable Diffusion 1.5?

The RTX 4090: 80.14 vs 38.24 images/min, 110% faster on our bench.

Should I buy or rent a RTX 5090 for Stable Diffusion 1.5?

Its $1,999 launch price buys 5,139 rented hours at $0.39/hr, enough for about 31,561x 1,000 images of Stable Diffusion 1.5. Buy only if you'll run more than that.

How we test

Stable Diffusion 1.5 at 512px in diffusers, bf16, native precision with no offload, timed over three generations after a warmup, with power and VRAM sampled throughout. Image speed tracks tensor compute and architecture generation more than memory bandwidth, so the order here differs from our LLM boards.