llmrun

AMD · RDNA 2 · 16 GB VRAM tier

Best AI Models for AMD Radeon RX 6800 XT (16 GB)

Runs 14B models well; 27–31B only just fits.

16 GB GDDR6512 GB/s41 TFLOPS FP16300 WRDNA 2 2020
Buyabout $649

What LLMs can the RX 6800 XT run?

#ModelSpeedllmrun ScoreQuant · VRAM
1
Q4_K_M · 6.6 GB · 48.3 t/s
48.3 tok/sQ4_K_M · 6.6 GB
2
Qwen3.5 4BAlibaba
Q4_K_M · 3.4 GB · 94.2 t/s
94.2 tok/sQ4_K_M · 3.4 GB
3
Q4_K_M · 13.1 GB · 75.6 t/s
75.6 tok/sQ4_K_M · 13.1 GB
4
Phi 4Microsoft
Q4_K_M · 12.5 GB · 32.3 t/s
32.3 tok/sQ4_K_M · 12.5 GB
5
Q4_K_M · 9.0 GB · 37.3 t/s
37.3 tok/sQ4_K_M · 9.0 GB
See all 307 models on the RX 6800 XT →Best quant that fits · speeds estimated on this card

About the RX 6800 XT

The RX 6800 XT is an entry card in the 16 GB class: it runs 14B models well. It is power-hungry for its speed, and at its $649 MSRP it cost more per token than most of the cards compared. RDNA 2 generation, released 2020.

Speed in 16 GB#10512 GB/s
Per watt#150.16 tok/s per W on Qwen3.5 9B (9B params)
Per dollar#57.4 tok/s per $100 on Qwen3.5 9B (9B params)
GenerationRDNA 2released 2020

RX 6800 XT strengths and weaknesses

Strengths

  • Runs 35B MoE models: Qwen3.6 35B A3B at 67.9 tok/s in 15.7 GB

Weaknesses

  • 70B models don't fit: Llama 3.3 70B Instruct needs 51.3 GB at Q4 vs 16 GB here
  • Slow prompt reading: A 4K-token prompt on Qwen3.5 9B waits 8.7 s for the first token
  • ROCm, not CUDA: No FP8 weights; MXFP4 only through llama.cpp, not vLLM

Speed per dollar and per watt

On Qwen3.5 9B (9B params) at Q4_K_M. New prices are compared with new, used with used. The last two columns are the speed you get per $100 of price and per 100 W of board power; higher is better. The RX 6800 XT has no current price, so it is shown at its MSRP.

CardNew pricetok/stok/s per $100tok/s per 100 W
about $84068.7
8.2
27.5
about $1,13090.6
8.0
25.5
RTX 5070 Ti16 GBBest new value
about $1,17091.6
7.8
30.5
RX 907016 GB
about $80060.4
7.6
27.5
about $64948.3
7.4
16.1
about $81560.4
7.4
19.9
about $1,69098.1
5.8
27.3
about $59030.2
5.1
18.9
CardUsed pricetok/stok/s per $100tok/s per 100 W
RTX 3060 12GB12 GBBest used value
about $32936.8
11.2
21.6
RX 907016 GB
about $65060.4
9.3
27.5
about $1,00090.6
9.1
25.5
about $57551.5
9.0
25.8
about $1,10091.6
8.3
30.5
about $67551.5
7.6
23.4
about $72251.5
7.1
18.1
about $1,10073.3
6.7
22.9

Cost per token: the RX 6800 XT against 12–32 GB cards

On Qwen3.5 9B (9B params, Q4_K_M, 4K context). Speed, cost per token and power per token depend on the model.

12 GB16 GB24 GB32 GBthis cardat MSRP
Cost per 1M output tokenson Qwen3.5 9B · card over 3 years + power
$1.11
Card, MSRP
$0.85
Power
$0.26
3-year cost of ownership$846
Or rent an RTX 3090 in the cloud$0.20/hr

Renting costs as much as buying after ≈3,300 hours (≈2.2 years at 4 h a day).

Include card price

Each dot is a card; hover or tap it for its numbers, click to open it. Cards without a price for the chosen basis are left out. How we calculate cost per token

Similar GPUs

Cards people weigh against the RX 6800 XT, each with the one reason it is worth a look. Speeds on Qwen3.5 9B.

RX 6800 XT tokens per second by model size

Output speed depends on memory bandwidth (512 GB/s). Grey rows need more than 16 GB.

  1. 9BQwen3.5 9B · Q4_K_M · 6.6 GB
    48.3tok/s
  2. 14BQwen3 14B · Q4_K_M · 11.9 GB
    32.3tok/s
  3. 27–31BQwen3.8 27B · Q3_K_L · 15.4 GB tight · Q3_K_L
    20.5tok/s
  4. 35B MoEQwen3.6 35B A3B · IQ3_S · 15.7 GB tight · IQ3_S
    67.9tok/s
  5. 70BLlama 3.3 70B Instruct · not at 4-bit
    needs 51.3 GB
  6. 120B MoEGPT OSS 120B · not at 4-bit
    needs 70.8 GB

Estimated speeds: Q4_K_M, 4K context, one user. How we estimate

All 1057 models on the RX 6800 XT

Featured only

Best quant that fits, ordered by llmrun Score. Fit grades how well it runs here, S best. How ranking works

LLM models compatible with AMD Radeon RX 6800 XT — ranked by Score, recency and Fit
ModelVRAMScoreFit
Ornith 1.5 9B OBLITERATED
Q4_K_M·48.3 t/s
6.6 GBA79, Runs well
Q4_K_M·116.4 t/s
4.8 GBS94, Runs great
LensVLM 9B
Q4_K_M·49.5 t/s
6.5 GBA79, Runs well
Qwopus3.5 9B v3
Q4_K_M·48.3 t/s
6.6 GBA79, Runs well
HARP 1B
Q4_K_M·787.7 t/s
0.4 GBS100, Runs great
Crowd V1
BF16·138.4 t/s
3.7 GBS96, Runs great
BF16·714.4 t/s
0.4 GBS100, Runs great
Tiny Lfm2ForCausalLM 2.5
Q4_K_M·1024.0 t/s
0.5 GBS100, Runs great
Qwen3.8 4B Distill
Q4_K_M·94.2 t/s
3.4 GBS90, Runs great
Qwen3.5 0.8B
Q4_K_M·353.1 t/s
0.9 GBS100, Runs great
Nanbeige4.2 3B
Q4_K_M·106.3 t/s
3.5 GBS92, Runs great
Q4_K_M·30720.0 t/s
0.3 GBS100, Runs great
Tiny Lfm2ForCausalLM
Q4_K_M·1024.0 t/s
0.5 GBS100, Runs great
JevK5
Q4_K_M·102.7 t/s
3.2 GBS92, Runs great
Olmo 3 7B Instruct
Q4_K_M·53.4 t/s
8.4 GBA81, Runs well

RX 6800 XT specs, power and PSU

Specs

Architecture
RDNA 2
VRAM
16 GB GDDR6
Memory bandwidth
512.0 GB/s
FP16 (dense)
41.47 TFLOPS
Stream processors
4,608
TDP
300 W
Released
2020-12-08
MSRP
$649

RX 6800 XT FAQ

Is the RX 6800 XT still worth it in 2026?

At its MSRP of $649 you get 7.4 tok/s per $100 on Qwen3.5 9B, which ranks 5th of the 8 cards compared here; it is also the 10th fastest out of 17 cards with 16 GB. It runs 14B models well; 27–31B only just fits.

What is the largest model the RX 6800 XT can run?

Gemma 4 26B A4B IT (25.8B) is the largest at 4-bit or better: at Q4_K_S it uses 15.5 GB of 16 GB, and runs at about 69.4 tok/s. At 3-bit, a bigger model fits too: Gemma 2 27B IT (27.2B) at IQ3_M, 15.0 GB.

Can the RX 6800 XT run Qwen3.5 9B?

Yes. Qwen3.5 9B fits at Q4_K_M, using 6.6 GB of 16 GB, and it is the best model that runs well on this card.

Can the RX 6800 XT run 70B models?

No. Llama 3.3 70B Instruct needs 51.3 GB at Q4, more than the 16 GB on this card.

How many tokens per second does the RX 6800 XT give?

About 48.3 tok/s on Qwen3.5 9B at Q4_K_M, with the first token after 8.7 s on a 4K-token prompt.

What power supply does the RX 6800 XT need?

Plan a 600 W PSU (2× the 300 W TDP).

Is 16 GB enough for coding and agents?

Yes for coding: GPT OSS 20B, the best of the 2 coding models that fit, runs at about 76 tok/s. For agents, not yet: no agent-scored model fits in less than 96 GB.

Is renting cheaper than buying an RX 6800 XT?

An RTX 3090 (24 GB) rents from $0.20/hr. Renting costs as much as buying after ≈3,300 hours (≈2.2 years at 4 h a day).