COMPARE / B300 VS MI355X
B300 vs MI355X
Specs from the chip makers' datasheets; prices from the live Compute Cafe panel, refreshed hourly. Every rate is an on-demand published price with a source receipt.
CHEAPEST B300
$4.480/hr
IO.NET · median $8.54 · 22 providers
CHEAPEST MI355X
$2.590/hr
Vultr · median $5.99 · 3 providers
CHEAPER RIGHT NOW
MI355X
live panel, 2026-09-27
| B300 | MI355X | |
|---|---|---|
| MAKER | NVIDIA | AMD |
| ARCHITECTURE | Blackwell Ultra | CDNA 4 |
| LAUNCHED | 2025 | 2025 |
| MEMORY | 288 GB HBM3e | 288 GB HBM3e |
| MEMORY BANDWIDTH | 8 TB/s | 8 TB/s |
| TENSOR COMPUTE | ~1.5x B200 tensor throughput (FP4-focused) | 2.3 PFLOPS FP16/BF16 dense; FP4 paths at 4x |
| POWER DRAW | up to 1,400 W | not published as a single figure (OAM module, platform-dependent) |
| INTERCONNECT | NVLink 5.0 1.8 TB/s | Infinity Fabric / UALink |
HOW TO CHOOSE
MI355X vs B300
Same 288 GB / 8 TB/s class, competing directly. NVIDIA brings CUDA maturity; AMD brings supply and often price. The real comparison is your stack's ROCm support.
Workload fit
B300: reasoning-model serving, largest-model inference. MI355X: large-model inference, training, cuda-locked stacks.
B300 VS MI355X - FAQ
Which is cheaper to rent, B300 or MI355X?
By today's published on-demand rates: B300 starts at $4.480/GPU/hr (median $8.54, 22 providers) and MI355X starts at $2.590/GPU/hr (median $5.99, 3 providers). The cheapest live listing is the MI355X at Vultr. Figures recompute from the panel on every refresh.
B300 or MI355X - which should I rent?
B300: The B300 (Blackwell Ultra) is NVIDIA's inference-first Blackwell refresh: 288 GB of HBM3e - half again the B200's memory - with FP4 throughput tuned for reasoning models that generate long chains of thought. MI355X: The MI355X is AMD's CDNA 4 flagship: 288 GB of HBM3e aimed squarely at large-model inference and training, with FP4 support matching Blackwell Ultra's pitch. The side-by-side spec table and live price rows above give the full picture.
Where can I rent B300 and MI355X?
22 providers publish B300 rates and 3 publish MI355X rates on Compute Cafe. Every row links to the provider's own published price - committed-use and reserved rates are excluded.
Full pricing: B300 · MI355X · all comparisons