Cisco 300-640 Practice Test Questions Answers

The Cisco UCS C885A M8 with NVIDIA H200 GPUs is purpose-built for dense accelerated computing and directly satisfies the NVLink requirement. Cisco's C885A M8 NVIDIA configuration supports eight H100 or H200 SXM Tensor Core GPUs on an HGX platform. Those GPUs are interconnected using NVIDIA NVLink, providing the high-bandwidth GPU-to-GPU communication necessary for distributed tensor processing inside the server.

The platform also provides substantial host-memory capacity, dual AMD EPYC processors, high-speed local NVMe storage, multiple 400-GbE adapters for inter-node GPU communication, and Cisco Intersight integration. These capabilities make it appropriate for large language models, generative AI training, fine-tuning, RAG, and large inference workloads.

Option A does not provide the same HGX NVLink-based eight-GPU architecture with an L40 configuration. Option B uses AMD accelerators; AMD GPU connectivity employs AMD interconnect technologies rather than NVIDIA NVLink. Option C is designed for materially different workload and GPU-density requirements and does not deliver the HGX H200 NVLink topology specified by the scenario.

The critical selection criterion is not merely whether a server can host a discrete GPU. The question explicitly requires direct GPU-to-GPU access through NVLink , which identifies the NVIDIA HGX-based C885A M8 configuration.

Study Guide Reference: AI Infrastructure Components and Architecture — compute selection based on CPU, GPU, memory, virtualization, interconnect performance, and workload requirements.

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Cisco Intersight Fleet Management is designed specifically for large numbers of geographically distributed systems where infrastructure and workloads must be deployed consistently across remote sites. Cisco describes Fleet Management as providing location profiles and reusable Blueprints that support zero-touch provisioning of hardware and operating systems after devices are claimed in Intersight. This directly addresses the scenario's requirement to manage different branch-office locations and automate their OS installation and configuration at scale.

A fleet abstraction removes the operational burden of individually configuring every remote server. Administrators can define standardized site and workload characteristics centrally, then reproduce the configuration across distributed infrastructure with policy consistency. This is particularly valuable for edge AI, where hundreds or thousands of sites may host inference workloads without dedicated local IT personnel.

Domain management focuses on UCS domains rather than mass deployment across geographically distributed sites. Server management provides lifecycle operations for individual or grouped servers but does not provide the location-profile and Blueprint-based fleet abstraction requested. Chassis management controls chassis-level resources and therefore does not address workload rollout across numerous sites.

Study Guide Reference: AI Infrastructure Deployment and Data Management — Cisco Intersight deployment, orchestration, provisioning, and distributed AI infrastructure.

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The UCS X9516 X-Fabric Module provides PCIe Gen5 connectivity between supported M8 compute nodes and X580p PCIe nodes. Before enabling that connectivity, the affected compute nodes must be powered down and equipped with the appropriate UCS PCI Gen5 mezzanine cards .

Cisco identifies the UCSX-V5-PCIME rear mezzanine card as a required hardware component for X580p connectivity. The card provides PCIe Gen5 electrical lanes between each CPU and the X9516 X-Fabric modules. Cisco also specifies that companion compute-node host power must be off for insertion or removal operations involving X580p PCIe connectivity, and that X9516 modules must be installed before the X580p PCIe nodes are installed.

Therefore, powering down the affected blades and installing their required PCI mezzanine cards are the appropriate preparatory actions.

The IFMs provide normal UCS network connectivity and do not need to be powered off or disconnected from Fabric Interconnects merely to install the X-Fabric modules. Similarly, disconnecting the Device Connector is unrelated to physical PCIe fabric installation and would unnecessarily interrupt Intersight connectivity.

Study Guide Reference: AI Infrastructure Deployment and Data Management — Cisco UCS X-Series GPU expansion, X-Fabric, PCIe connectivity, and hardware deployment.

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NVIDIA Collective Communications Library (NCCL) is the appropriate framework for validating communication performance between NVIDIA GPU nodes. NCCL provides highly optimized implementations of collective operations such as AllReduce, AllGather, Reduce, Broadcast, and ReduceScatter. These operations closely represent the communication patterns generated by distributed AI training and therefore provide much more meaningful validation of GPU-cluster performance than conventional network-throughput tests.

NCCL-based benchmarks can reveal whether GPU-to-GPU communication is achieving expected bandwidth and latency across NVLink, PCIe, and the external backend network. They are particularly useful when validating RoCEv2 fabrics because distributed training performance depends on collective communication efficiency rather than simple host-to-host TCP throughput.

iPerf measures conventional TCP or UDP network performance between hosts and is useful for basic network validation, but it does not exercise NVIDIA GPU collective communications. Spirent and Ixia provide sophisticated packet-generation and network-testing platforms, yet they test the network primarily from a packet-forwarding perspective rather than measuring actual GPU collective-operation behavior.

For a newly deployed NVIDIA AI cluster, NCCL benchmarking therefore provides workload-representative validation of the end-to-end GPU communication architecture and can expose problems involving topology, NIC configuration, congestion control, bandwidth imbalance, or fabric design.

Study Guide Reference: AI Infrastructure Operations and Troubleshooting — performance benchmarking, NVIDIA GPU communications, backend-fabric validation, and distributed AI workload testing.

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Cisco Nexus 9000 integration with NVIDIA adaptive-routing capabilities requires the Nexus switch to enable the Spectrum-X hardware profile . Cisco's current NX-OS configuration guide explicitly specifies the global configuration command hardware profile spectrum-x to enable NVIDIA Spectrum-X adaptive routing. When a Nexus switch peers with a supported NVIDIA NIC, this capability allows the NIC to handle packet reordering created by granular techniques such as per-packet Dynamic Load Balancing.

This is particularly important for AI training because large synchronized RDMA flows can create uneven utilization under conventional hash-based ECMP. Cisco explains that per-packet DLB can spray packets over multiple paths and that NVIDIA adaptive routing/direct data placement enables the receiver to correctly handle packets that arrive out of order, improving utilization and collective-operation performance.

Option A is not the documented NX-OS configuration syntax. Option B is not the Cisco-prescribed Nexus integration command. Option D may be relevant to traffic classification in other designs but does not activate Spectrum-X adaptive-routing interoperability.

Therefore, the Cisco-documented configuration is C. This differs from the supplied file's marked answer B.

Study Guide Reference: 3.0 AI Infrastructure Deployment and Data Management — 3.1.d Load distribution.

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