
Generative AI applications exploded in late‑2023 and 2024, driving record demand for GPUs and exposing a split between memory‑rich accelerators and latency‑oriented chips. By the end of 2025, two competitors dominate the data‑center conversation: AMD’s Instinct MI300X and NVIDIA’s Blackwell B200. Each represents a different philosophy: memory capacity and value vs raw compute and ecosystem maturity. Meanwhile, AMD announced MI355X and MI325X road‑map entries, promising larger HBM3E stacks and new low‑precision math modes. This article synthesizes research, independent benchmarks, and industry commentary to help you pick the best GPU, with a particular focus on Clarifai’s multi‑cloud inference and orchestration platform.
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Section |
AI‑Friendly Takeaways |
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Architecture |
MI300X uses chiplet‑based CDNA 3 design with 192 GB HBM3 and 5.3 TB/s bandwidth; the B200’s dual‑die Blackwell packages 180–192 GB HBM3E and 8 TB/s bandwidth. The upcoming MI355X ups memory to 288 GB, supports FP6/FP4 modes with up to 20 PFLOPS and provides 79 TFLOPS FP64 throughput. |
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Performance |
Benchmarks show MI300X achieving 18,752 tokens/s per GPU—about 74 % of H200 throughput and higher latency due to software overhead. MI355X training runs 2.8× faster than MI300X for Llama‑2 70B FP8 fine‑tuning. Independent InferenceMAX results report MI355X matching or beating B200 on cost‑per‑token and tokens per megawatt. |
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Economics |
The B200 sells for US$35–40 k and draws roughly 1 kW per card; MI300X costs US$10–15 k and uses 750 W. An eight‑GPU training pod costs roughly US$9 M for B200 vs US$3 M for MI300X due to lower card price and power draw. MI355X consumes ~1.4 kW but delivers 30 % more tokens per watt than MI300X. |
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Software |
NVIDIA’s CUDA stack offers mature debugging and tooling; ROCm has improved drastically. ROCm 7.0/7.1 now covers ~92 % of CUDA 12.5 API, provides graph‑capture primitives, and packages tuned containers within 24 hours of release. Independent reports highlight fewer bugs and quicker fixes on AMD’s stack, though CUDA still holds a productivity edge. |
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Use Cases |
MI300X excels at single‑GPU inference for 70–110 billion‑parameter models, memory‑bound tasks and RAG pipelines; the B200 leads in sub‑100 ms latency and large‑scale pre‑training; MI355X targets 400–500 B+ models, HPC+AI workloads and high tokens‑per‑dollar scenarios; MI325X offers 256 GB memory for mid‑range tasks. Clarifai’s orchestration helps combine these GPUs for optimal cost and performance. |
With these high‑level findings in mind, let’s dive into the architectures, performance data, economics, software ecosystems, use cases and future outlook for MI300X, MI325X, MI355X, and B200—and explain how Clarifai’s compute orchestration can help you build a flexible, cost‑efficient GPU stack.
The MI300X and its successors (MI325X, MI355X) are built on AMD’s CDNA 3 and CDNA 4 architectures, which use chiplet‑based designs to pack compute and memory into a single accelerator. Each chiplet, or XCD, is fabricated on a 3 nm or 4 nm process (depending on generation), and multiple chiplets are stitched together via the Infinity Fabric. This allows AMD to stack 192 GB of HBM3 (MI300X) or 256 GB (MI325X) or 288 GB of HBM3E (MI355X) around compute dies, delivering 5.3 TB/s to 8 TB/s of bandwidth. The memory sits close to compute, reducing DRAM round‑trip latency and enabling large language models to run on a single device without sharding.
The B200, by contrast, uses NVIDIA’s Blackwell architecture, which adopts a dual‑die package. Two reticle‑limit dies share a 10 TB/s interconnect and present themselves as a single logical GPU, with up to 180 GB or 192 GB of HBM3E memory and approximately 8 TB/s of bandwidth. NVIDIA pairs these chips with NVLink‑5 switches to build systems like the NVL72, where 72 GPUs act as one with a unified memory space.
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GPU |
HBM memory |
Bandwidth |
Power draw |
Notable precision modes |
FP64 throughput |
Price (approx.) |
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MI300X |
192 GB HBM3 |
5.3 TB/s |
~750 W |
FP8, FP16/BF16 |
Lower than MI355X |
US$10–15 k |
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MI325X |
256 GB HBM3E |
~6 TB/s |
Similar to MI300X |
FP8, FP16/BF16 |
Slightly higher than MI300X |
US$16–20 k (est.) |
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MI355X |
288 GB HBM3E |
8 TB/s |
~1.4 kW |
FP4/FP6/FP8 (up to 20 PFLOPS FP6/FP4) |
79 TFLOPS FP64 |
US$25–30 k (projected) |
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B200 |
180–192 GB HBM3E |
8 TB/s |
~1 kW |
FP4/FP8 |
~37–40 TFLOPS FP64 |
US$35–40 k |
Why the Differences Matter: MI355X’s 288 GB of memory can hold models with 500+ billion parameters, reducing the need for tensor parallelism and minimizing communication overhead. The MI355X’s support for FP6 yields up to 20 PFLOPS of ultra‑low precision throughput, roughly doubling B200’s capacity in this mode. Meanwhile, the B200’s dual‑die design simplifies scaling and, paired with NVLink‑5, forms a unified memory space across dozens of GPUs. Each approach has implications for cluster design and developer workflow, which we explore next.
In multi‑GPU systems, the interconnect often determines how well tasks scale. NVIDIA uses NVLink‑5 and NVSwitch fabric; the NVL72 system interconnects 72 GPUs and 36 CPUs into a single pool, delivering around 1.4 EFLOPS of compute and a unified memory space. AMD’s alternative is Infinity Fabric, which links up to eight MI300X or MI355X GPUs in a fully connected mesh with seven high‑speed links per card. Each pair of MI355X cards communicates directly at roughly 153 GB/s, yielding about 1.075 TB/s total peer‑to‑peer bandwidth.
Single‑GPU inference: In independent MLPerf‑inspired tests, MI300X delivers 18 752 tokens per second on large language model inference, roughly 74 % of H200’s throughput. Latency scales at around 4.20 ms for an eight‑GPU MI300X cluster, compared with 2.40 ms on competing platforms. The lower efficiency arises from software overheads and slower kernel optimizations in ROCm compared with CUDA.
Training performance: On the Llama‑2 70B LoRA FP8 workload, the MI355X slashes training time from ~28 minutes on MI300X to just over 10 minutes. This represents a 2.8× speed‑up, attributable to enhanced HBM3E bandwidth and ROCm 7.1 improvements. When compared to the average of industry submissions using the B200 or GB200, the MI355X’s FP8 training times are within ~10 %—showing near parity.
InferenceMax results: An open benchmarking initiative running vLLM workloads across multiple cloud providers concluded that the MI355X matches or beats competing GPUs on tokens per dollar and offers a ~3× improvement in tokens per megawatt compared with previous AMD generations. The same report noted that MI325X surpasses the H200 on TCO for summarization tasks, while MI300X sometimes outperforms the H100 in memory‑bound regimes.
Latency vs throughput: The MI355X emphasises memory capacity over minimal latency; early engineering samples show inference throughput improvements of 2× compared with B200 on 400 B+ parameter models using FP4 precision. However, the B200 typically maintains a latency advantage for smaller models and real‑time applications.
Scaling considerations: Multi‑GPU efficiency depends on both hardware and software. The MI300X and MI325X scale well for large batch sizes but suffer when many small requests stream in—a common scenario for chatbots. The MI355X’s larger memory reduces the need for pipeline parallelism and thus reduces communication overhead, enabling more consistent scaling across workloads. NVLink‑5’s unified memory space in NVL72 systems provides superior scaling for extremely large models (>400 B), albeit at high cost and power consumption.
Card price: According to market surveys, the B200 retails for US$35–40 k, while the MI300X sells for US$10–15 k. MI325X is expected around US$16–20 k (unofficial), and MI355X is projected at US$25–30 k. These price differentials reflect not just chip cost but also memory volume, packaging complexity and vendor premiums.
Power consumption: The B200 draws roughly 1 kW per card, whereas the MI300X draws ~750 W. MI355X raises the TDP to ~1.4 kW, requiring liquid cooling. Despite the higher power draw, early data shows a 30 % tokens‑per‑watt improvement compared with MI300X. Energy‑aware schedulers can exploit this by running MI355X at high utilization and powering down idle chips.
Training pod costs: AI‑Stack’s economic analysis estimates that an eight‑GPU MI300X pod costs around US$3 M including infrastructure, while a B200 pod costs ~US$9 M due to higher card prices and higher power consumption. This translates to lower capital expenditure (CAPEX) and lower operational expenditure (OPEX) for MI300X, albeit with some performance trade‑offs.
Tokens per megawatt: Independent benchmarks found that MI355X delivers a ~3× higher tokens‑per‑megawatt score than its predecessor, a critical metric as electricity costs and carbon taxes rise. Tokens per watt matters more than raw FLOPS when scaling inference services across thousands of GPUs.
The EU AI Act and similar regulations emerging worldwide include provisions to track energy use and carbon emissions of AI systems. Data centers already consume over 415 TWh annually, with projections to reach ~945 TWh by 2030. A single NVL72 rack can draw 120 kW, and a rack of MI355X modules can exceed 11 kW per 8 GPUs. Selecting GPUs with lower power and higher tokens per watt becomes essential—not only for cost but also for regulatory compliance. Clarifai’s energy‑aware scheduler helps customers monitor grams of CO₂ per prompt and allocate workloads to the most efficient hardware.
CUDA remains the most widely adopted GPU programming framework. It offers TensorRT‑LLM for optimized inference, a comprehensive debugger, and a large library ecosystem. Developers benefit from extensive documentation, community examples and faster time‑to‑production. NVIDIA’s Transformer Engine 2 provides FP4 quantization routines and features like Multi‑Transformer for merging attention blocks.
AMD’s open‑source ROCm has matured rapidly. In ROCm 7, AMD added graph capture primitives aligned with PyTorch 2.4, improved kernel fusion, and introduced support for FP4/FP6 datatypes. Upstream frameworks (PyTorch, TensorFlow, JAX) now support ROCm out of the box, and container images are available within 24 hours of new releases. HIP tools now cover about 92 % of CUDA 12.5 device APIs, easing migration.
Reports from independent benchmarking teams indicate that the ROCm/vLLM stack exhibits fewer bugs and easier fixes than competing stacks. This is due in part to open‑source transparency and rapid iteration. ROCm’s open nature also allows the community to contribute features like Flash‑Attention 3, which is now available on both CUDA and ROCm.
The CUDA moat is still real: developers commonly find it easier to debug and optimize workloads on CUDA due to mature profiling tools and a rich plugin ecosystem. ROCm’s debugging tools are improving, but there remains a learning curve, and patching issues may require deeper domain knowledge. On the positive side, ROCm’s open design means that community bug fixes can land quickly. Engineers interviewed by independent news sources note that AMD’s software issues often revolve around kernel tuning rather than fundamental bugs, and many report that ROCm’s improvements have narrowed the performance gap to within 10–20 % of CUDA.
For readers in India (notably Chennai), availability matters. Major Indian cloud providers are starting to offer MI300X and MI325X instances via local data centers. Some decentralized GPU marketplaces also rent MI300X and B200 capacity at lower cost. Clarifai’s Universal GPU API integrates with these platforms, allowing you to deploy retrieval‑augmented systems locally while maintaining centralised management.
AMD’s roadmap fills the gap between MI300X and MI355X with MI325X, featuring 256 GB HBM3E and 6 TB/s bandwidth. Independent analyses suggest MI325X matches or slightly surpasses H200 for LLM inference and offers 40 % faster throughput and 30 % lower latency on certain models. MI355X, the first CDNA 4 chip, takes the memory up to 288 GB, adds FP6 support and boasts 20 PFLOPS FP6/FP4 throughput, with double‑precision performance at 79 TFLOPS. AMD claims MI355X offers up to 4× theoretical compute over MI300X and up to 1.2× higher inference throughput than B200 on certain vLLM workloads.
NVIDIA’s roadmap includes Grace‑Blackwell (GB200), a CPU‑GPU superchip that connects a B200 with a Grace CPU via NVLink‑C2C, forming a unified package. GB200 systems promise 1.4 EFLOPS of compute across 72 GPUs and 36 CPUs and are targeted at training models over 400 B parameters. The B300 (Hopper refresh) is expected to deliver FP4/FP8 efficiency improvements and integrate with the Grace ecosystem.
Supply constraints for HBM memory remain a limiting factor. Experts warn that advanced process nodes and 3D stacking techniques will keep memory scarce until 2026. Regulatory pressures like the EU AI Act are pushing companies to track carbon per prompt and adopt energy‑efficient hardware. Expect tokens‑per‑watt and cost‑per‑token metrics to drive purchasing decisions more than peak FLOPS.
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GPU |
Pros |
Cons |
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MI300X |
Low price; 192 GB memory; good for 70–110 B models; 750 W power; supports FP8/FP16 |
Lower raw throughput; latency ~4 ms at 8 GPUs; software overhead; no FP6/FP4 |
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MI325X |
256 GB memory; ~6 TB/s bandwidth; 40 % faster throughput than H200; good for summarization |
Price higher than MI300X; still uses ROCm; power similar to MI300X |
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MI355X |
288 GB memory; 20 PFLOPS FP6/FP4; 79 TFLOPS FP64; tokens‑per‑watt improved |
1.4 kW TDP; cost high; requires liquid cooling; software still maturing |
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B200 |
High raw throughput; low latency; mature CUDA ecosystem; NVLink‑5 unified memory |
High price; 1 kW power draw; 180–192 GB memory; limited FP64 performance |
The race between MI300X, MI325X, MI355X and B200 underscores a broader truth: the “best” GPU depends on your workload, budget, and sustainability goals. MI300X offers an affordable path to memory‑rich inference but trails in raw throughput. MI325X bridges the gap with more memory and bandwidth, edging out the H200 in some benchmarks. MI355X takes memory capacity and ultra‑low precision compute to the extreme, delivering high tokens per watt and cost‑per‑token leadership but requiring significant power and advanced cooling. B200 remains the latency king and boasts the most mature software ecosystem, yet comes at a premium price and offers less double‑precision performance.
Rather than choosing a single winner, modern AI infrastructure embraces heterogeneous fleets. Clarifai’s compute orchestration and multi‑cloud deployment tools allow you to run the right model on the right hardware at the right time. Energy‑aware scheduling, retrieval‑augmented generation, and cost‑per‑token optimization are built into the platform. As GPUs continue to evolve—with MI400 and Grace‑Blackwell on the horizon—flexibility and informed decision‑making will matter more than ever.
Q1: Is MI355X available now, and when will it ship?
AMD announced MI355X for late‑2025 with limited availability through partner programs. Full production is expected in mid‑2026 due to HBM supply constraints and the need for liquid cooling infrastructure. Check with your cloud provider or Clarifai for current inventory.
Q2: Can I mix MI300X and B200 GPUs in the same cluster?
Yes. Clarifai’s Universal GPU API and orchestrator support heterogeneous clusters. You can route latency‑critical workloads to B200 while directing memory‑bound or cost‑sensitive tasks to MI300X/MI325X/MI355X. Data parallelism across different GPU types is possible with frameworks like vLLM that support mixed hardware.
Q3: How do FP6 and FP4 modes improve performance?
FP6 and FP4 are low‑precision formats that reduce memory footprint and increase arithmetic density. On MI355X, FP6/FP4 throughput reaches 20 PFLOPS, roughly 2× higher than B200’s FP6/FP4 capacity. These modes allow larger batch sizes and faster inference when precision loss is acceptable.
Q4: Do I need liquid cooling for MI355X?
Yes. The MI355X has a TDP around 1.4 kW and is designed for OAM/UBB form factors with direct‑to‑plate liquid cooling. Air‑cooled variants may exist (MI350X) but have reduced power limits and throughput.
Q5: What about the software learning curve for ROCm?
ROCm has improved significantly; over 92 % of CUDA APIs are now covered by HIP. However, developers may still face a learning curve when tuning kernels and debugging. Clarifai’s platform abstracts these complexities and provides pre‑tuned containers for common workloads.
Q6: How does Clarifai help optimize cost and sustainability?
Clarifai’s compute orchestration automatically schedules workloads based on latency, memory and cost constraints. Its energy‑aware scheduler tracks grams of CO₂ per prompt and chooses the most energy‑efficient hardware, while the Federated Query service allows retrieval across multiple data sources without vendor lock‑in. Together, these capabilities help you balance performance, cost and sustainability.
Developer advocate specialized in Machine learning. Summanth work at Clarifai, where he helps developers to get the most out of their ML efforts. He usually writes about Compute orchestration, Computer vision and new trends on AI and technology.
Developer advocate specialized in Machine learning. Summanth work at Clarifai, where he helps developers to get the most out of their ML efforts. He usually writes about Compute orchestration, Computer vision and new trends on AI and technology.
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© 2023 Clarifai, Inc. Terms of Service Content TakedownPrivacy Policy