AMD MI300X vs B300: Specs, VRAM & Price
Short answer: choose the B300 when 288 GB of VRAM is the gating requirement. Choose the AMD MI300X when 192 GB is enough for the workload and the lower hourly rate points that way.
The AMD MI300X has 192 GB of VRAM; the B300 has 288 GB.
You can rent both by the hour, no purchase required. AMD MI300X from $2.63/GPU/hr; B300 from $9.89/GPU/hr. The AMD MI300X is 73% cheaper at the entry rate.
AMD MI300X
Good for training and serving frontier-scale LLMs
B300
Good for training and serving frontier-scale LLMs
Last updated: 2026-10-10 22:48:11 UTCRefreshes hourly
Specs side by side
| Spec | AMD MI300X | B300 |
|---|---|---|
| VRAM | 192 GB | 288 GB |
| Memory bandwidth | 5.3 TB/s | – |
| Architecture | CDNA3 | Blackwell Ultra |
| Compute capability | n/a | 10.3 |
| Precisions in hardware | FP32, FP16, BF16, FP8, INT4 | FP32, FP16, BF16, FP8, INT4 |
| Peak FP16/BF16 tensor TFLOPS | 1,307.4 TFLOPS | – |
| Peak FP8 tensor TFLOPS | 2,614.9 TFLOPS | – |
| NVLink / multi-GPU interconnect | Infinity Fabric | – |
| Max board power (TDP) | 750W | – |
| Regions | 2 | 1 |
On-demand price
| Rate | AMD MI300X | B300 |
|---|---|---|
| Lowest per GPU/hr | $2.63/GPU/hr | $9.89/GPU/hr |
Which is better for AI: AMD MI300X or B300?
Choose the B300 when 288 GB of VRAM is the gating requirement. Choose the AMD MI300X when 192 GB is enough for the workload and the lower hourly rate points that way.
AMD MI300X vs B300: common questions
Is the AMD MI300X or the B300 better for AI?
Short answer: choose the B300 when 288 GB of VRAM is the gating requirement. Choose the AMD MI300X when 192 GB is enough for the workload and the lower hourly rate points that way.
Is the AMD MI300X or the B300 cheaper to rent?
On Aquanode's live marketplace the AMD MI300X starts at $2.63/GPU/hr (median $2.63/GPU/hr) and the B300 starts at $9.89/GPU/hr (median $9.89/GPU/hr). The AMD MI300X is the cheaper of the two at the entry rate, by 73%.
What is the difference between the AMD MI300X and the B300?
The AMD MI300X has 192 GB of VRAM against the B300's 288 GB; the AMD MI300X is a CDNA3 part and the B300 is Blackwell Ultra; both run BF16, FP8, INT4 workloads in hardware. On price, the AMD MI300X lists from $2.63/GPU/hr and the B300 from $9.89/GPU/hr.
How widely available are the AMD MI300X and the B300?
The AMD MI300X is listed in 2 regions and the B300 in 1 region right now.
How much does 1,000 GPU-hours cost on the AMD MI300X vs the B300?
At the lowest rates listed today, 1,000 GPU-hours costs $2,629 on the AMD MI300X and $9,889 on the B300, a difference of $7,260 for the same runtime. Rates are per GPU per hour and update hourly.
How much VRAM does the AMD MI300X have compared to the B300?
The AMD MI300X has 192 GB of VRAM; the B300 has 288 GB.
How this comparison is calculated
Every price is normalized to a per-GPU hourly rate using the same pipeline as every other pricing surface on Aquanode, and only the cheapest qualifying offer per provider is shown. A dash means that provider does not currently list that GPU.
Architecture, compute capability and supported precisions come from each vendor's published datasheet for that generation, not from the marketplace feed. This page regenerates at most once per hour.
Memory bandwidth, tensor TFLOPS, NVLink/interconnect and max board power are the same verified-from-datasheet figures shown on each model's own AMD MI300X page and B300 page, which link the primary vendor source for that model. A dash here means Aquanode hasn't verified that figure from a primary source yet, never a guess.
Go further
Check what fits in each card's memory with the AMD MI300X VRAM calculator and the B300 VRAM calculator, see vendor-published throughput in the GPU benchmarks and specs table, or browse every model by generation in the GPU index.
More AMD MI300X comparisons
More B300 comparisons
Related reading: AMD MI300X pricing and specs, ROCm vs CUDA, AMD vs NVIDIA GPUs for AI, AMD MI355X guide, and The best GPUs for AI, ranked.
