GPU comparison
RTX 4080 Super vs RTX 4090 for Stable Diffusion
Draft comparison for later controlled image-generation benchmark research.
Planning summary only. Verify exact GPU variants, runtime support, and workload behavior before making purchase decisions.
RTX 4080 Super
- VRAM
- 16 GB
- Memory type
- GDDR6X
- Bandwidth
- 736.3 GB/s
- Board power / TGP
- 320 W
RTX 4090
- VRAM
- 24 GB
- Memory type
- GDDR6X
- Bandwidth
- 1008 GB/s
- Board power / TGP
- 450 W
Quick planning summary
RTX 4080 Super: 16 GB | RTX 4090: 24 GB
RTX 4080 Super: 736.3 GB/s | RTX 4090: 1008 GB/s
RTX 4080 Super: Needs verification | RTX 4090: 450 W
Image workflow planning
RTX 4080 Super: medium | RTX 4090: medium
Benchmark evidence, exact board-partner variant, runtime compatibility, and workload fit.
Comparison table
| Field | RTX 4080 Super | RTX 4090 |
|---|---|---|
| Memory planning | ||
| VRAM | 16 GB | 24 GB |
| Memory type | GDDR6X | GDDR6X |
| Memory bus | 256-bit | 384-bit |
| Memory bandwidth | 736.3 GB/s | 1008 GB/s |
| Compute / architecture | ||
| Vendor | NVIDIA | NVIDIA |
| Architecture | Ada Lovelace | Ada Lovelace |
| Core / execution units | 10240 CUDA cores | 16384 CUDA cores |
| Power planning | ||
| Board power / TGP | 320 W | 450 W |
| Power connector | 1 x 16-pin | 1 x PCIe Gen5 (or 3 x 8-pin adapter) |
| Verification | ||
| Status | Source-backed GPU specs available | Source-backed GPU specs available |
| Data confidence | medium | medium |
| Last verified | 2026-05-29 | 2026-05-29 |
Cautious verdict
RTX 4090 has more source-backed VRAM headroom than RTX 4080 Super. RTX 4090 has higher listed memory bandwidth than RTX 4080 Super.
This is not a benchmark verdict, and it should not be treated as purchase guidance.
Final fit still depends on model size, quantization, runtime support, drivers, and tested workload behavior.
How to interpret this comparison
VRAM is capacity headroom, not guaranteed speed. Memory bandwidth can matter, but benchmark evidence is still needed before drawing performance conclusions.
Runtime support, drivers, and exact board-partner variants can change practical results. Use the VRAM Calculator before treating this comparison as purchase guidance.
RECOMMENDED NEXT STEP
Check model memory before choosing between these GPUs
Run your model assumptions through the VRAM Calculator, then return to GPU profiles for source notes and board-partner verification.
Use case notes
For local LLM planning, prioritize VRAM headroom and runtime compatibility. For image workflows, avoid assuming performance until benchmark evidence is attached.
When to choose cloud GPU instead
Consider cloud testing when memory estimates exceed local cards, when workloads are infrequent, or when validating before hardware purchase.
FAQ
Why compare 16 GB and 24 GB NVIDIA GPUs for image-generation planning?
The comparison helps separate capacity headroom from unsupported speed assumptions. Larger workflows may need more VRAM, but image-generation speed still requires benchmark evidence for the exact setup.
When should I use the VRAM Calculator first?
Use it before comparing cards so your shortlist matches estimated memory requirements.
When should I choose cloud GPU instead?
When local VRAM is below estimate, testing is occasional, or you need validation before buying.
Should I rely on this comparison as purchase guidance?
No. This page is planning guidance and intentionally avoids unsupported benchmark, price, availability, and buying claims.
Related GPU profiles
Sources and data confidence
RTX 4080 Super
Confidence: medium
Source types: official, database
RTX 4090
Confidence: medium
Source types: official, paper
No benchmark source is attached to this comparison, so benchmark claims are not included.