- Bandwidth (Memory Bandwidth)
- The rate at which data moves between a GPU's VRAM and its compute cores, measured in TB/s. Higher bandwidth means fewer memory bottlenecks during LLM inference. The NVIDIA B200 delivers 8 TB/s - critical for serving large models fast.
- Bare Metal
- A server you access directly, with no hypervisor or virtualization layer sitting between your workload and the hardware. You get the full, raw GPU - no shared overhead, no noisy neighbors. packet.ai's Bare Metal tier gives you exclusive access to a physical node.
- CUDA (Compute Unified Device Architecture)
- NVIDIA's parallel computing platform and programming model. Almost every major AI/ML framework (PyTorch, TensorFlow, JAX) runs on CUDA. When people say a library is "GPU-accelerated," they usually mean CUDA-accelerated.
- CUDA Cores
- The basic processing units inside an NVIDIA GPU that handle parallel compute tasks. More CUDA cores generally means more parallelism for matrix operations - the backbone of neural network training and inference.
- Distributed Training
- Training a neural network across multiple GPUs or nodes simultaneously, combining data parallelism, tensor parallelism, and pipeline parallelism to handle models and datasets too large for a single device. Communication overhead between GPUs is the primary bottleneck - gradient synchronization requires high-bandwidth interconnects (NVLink within a node, InfiniBand across nodes). A well-connected 8xH100 node delivers 900 GB/s all-to-all NVLink bandwidth, making it the baseline unit for serious distributed training runs.
- FLOPS (Floating Point Operations Per Second)
- A measure of raw GPU compute power. Modern AI hardware is measured in TFLOPS (trillions) or PFLOPS (quadrillions). FP16 and BF16 FLOPS are the relevant numbers for LLM workloads. The B200 delivers 4.5 PFLOPS of FP8 compute.
- FP8 / FP16 / BF16 / FP32
- Numeric precision formats used in GPU compute. Lower precision (FP8) fits more data in VRAM and runs faster - useful for inference. Higher precision (FP32) is more accurate - used in some training scenarios. BF16 is the current sweet spot for training large models.
- GPU (Graphics Processing Unit)
- A parallel processor originally designed for rendering graphics, repurposed for AI because its thousands of smaller cores excel at the matrix math that powers neural networks. Every product on packet.ai runs on NVIDIA data center GPUs.
- GPU Orchestration
- The automated management of GPU resources across infrastructure - provisioning, scheduling, monitoring, scaling, and lifecycle management without manual intervention. Without orchestration, GPUs sit idle, users queue for manual access, and fragmentation compounds. Modern GPU orchestration platforms go beyond basic scheduling to handle multi-tenancy, billing metering, auto-scaling, and software-defined GPU pooling across large fleets.
- GPU Scheduler
- The software component that decides which workload runs on which GPU, when, and with what priority. Simple schedulers treat GPUs as discrete units. Advanced schedulers operate at the resource level - understanding VRAM requirements, NVLink topology, and tenant priority to place workloads optimally. packet.ai runs haishare, a custom scheduler built by hosted.ai that uses time-quantum-based sharing, credit systems, and preemption to maximize utilization across a multi-tenant fleet.
- GPU Utilization
- The percentage of a GPU's compute capacity actively doing useful work at any given moment. Low utilization means you're paying for hardware that isn't working - the core inefficiency GPU orchestration platforms exist to solve. Memory utilization (VRAM usage) is a separate metric: a GPU can be compute-idle but memory-full, blocking new workloads from scheduling. Both numbers matter for fleet efficiency.
- GPU Virtualization
- Abstracting a physical GPU into one or more logical resources that can be assigned independently to different workloads or tenants. Rather than treating a GPU as all-or-nothing, virtualization introduces a layer that manages access to compute, memory, and bandwidth - allowing multiple workloads to share one physical device. The primary motivation is utilization: expensive GPUs should not sit idle because a single underutilizing workload owns the whole card.
- HBM (High Bandwidth Memory)
- The memory technology used in enterprise-class GPUs like the H100 and B200. Stacked directly on the chip package for extreme bandwidth. HBM3e on the B200 delivers 8 TB/s - compared to ~1 TB/s on consumer GDDR6 cards.
- HGX
- NVIDIA's server board standard for multi-GPU systems. An HGX B200 node packs 8 B200 GPUs connected via NVLink. When packet.ai says "HGX B200," it means the full 8-GPU board, not a single chip.
- MIG (Multi-Instance GPU)
- NVIDIA's feature on A100 and H100 that partitions a single GPU into up to 7 isolated slices, each with its own VRAM, compute, and memory bandwidth. Useful for running multiple smaller inference workloads on one physical GPU.
- NPU (Neural Processing Unit)
- A low-power processor core designed for on-device AI inference - found in Apple M-series chips, Qualcomm Snapdragon, and Intel Core Ultra. NPUs run quantized smaller models locally without sending data to a cloud API, consuming milliwatts vs. the hundreds of watts a data center GPU draws. They are not replacements for cloud GPUs: NPUs cannot train models, cannot serve large frontier models, and have a fraction of the memory capacity.
- NVLink
- NVIDIA's high-speed GPU-to-GPU interconnect. Where PCIe peaks at ~64 GB/s bidirectional, NVLink 4.0 on H100s delivers 900 GB/s. Essential for multi-GPU training where tensors need to move rapidly across GPUs.
- NVSwitch
- A dedicated NVIDIA chip that enables all-to-all NVLink communication between every GPU in an HGX node. Without NVSwitch, GPUs can only communicate with a few neighbors. With it, any GPU can talk to any other at full bandwidth.
- PCIe (Peripheral Component Interconnect Express)
- The interface connecting GPUs to the CPU and the rest of the server. PCIe GPUs share bandwidth with the CPU over this bus. SXM variants use NVLink instead, which is significantly faster for multi-GPU workloads.
- SXM
- NVIDIA's high-performance GPU form factor used in HGX nodes. SXM GPUs mount directly to a baseboard and connect via NVLink/NVSwitch, bypassing PCIe entirely. SXM variants have higher TDP and higher performance than their PCIe counterparts.
- Tensor Cores
- Specialized compute units inside NVIDIA GPUs designed for matrix multiply-accumulate operations - the dominant operation in neural network training and inference. Tensor Cores accelerate FP16, BF16, INT8, and FP8 workloads significantly faster than CUDA Cores alone.
- TDP (Thermal Design Power)
- The maximum sustained power a GPU draws under full load, measured in watts. The B200 SXM has a 1,000W TDP; the H100 SXM is 700W. Relevant for bare metal deployments where power affects total cost of ownership.
- TPU (Tensor Processing Unit)
- Google's custom AI accelerator, built specifically for the matrix operations that dominate neural network workloads. TPUs are fast and efficient within the Google Cloud ecosystem but require XLA compilation and have limited compatibility with the CUDA-native tools - vLLM, TGI, Flash Attention - that power most open-source AI workloads. In practice, the vast majority of GPU cloud inference and training runs on NVIDIA GPUs, not TPUs.
- VRAM (Video RAM)
- The on-chip memory of a GPU, separate from system RAM. The primary constraint when running large models - your model weights plus KV cache must fit in VRAM or you hit OOM (out-of-memory) errors. The B200 has 192 GB HBM3e; the H100 has 80 GB.
- Elastic GPU Provisioning
- Dynamically scaling GPU allocation up or down in response to workload demand without manual intervention. A workload can start with 1 GPU, scale to 8 during training, and release to 0 when idle - paying only for what it uses.
- GPU Generation (Ampere / Hopper / Blackwell / Ada)
- NVIDIA's GPU microarchitectures in successive generations. Ampere (2020): A100, RTX 3090 - introduced MIG and BF16. Hopper (2022): H100, H200 - added FP8, NVLink 4.0. Blackwell (2024): B200, GB200 - 192 GB HBM3e, 4.5 PFLOPS FP8. Ada Lovelace (2022): RTX 4090, RTX 6000 Pro - consumer/workstation line.
- GPU Overcommit / Oversubscription
- Allocating more virtual GPU capacity than physical hardware supports, betting that not all tenants peak simultaneously. Common when workload patterns are bursty - works at 60-70% average utilization.
- GPU Partitioning
- Dividing a single physical GPU into isolated slices assigned to separate workloads. Unlike time-slicing, partitioning gives each slice dedicated VRAM and compute running simultaneously. NVIDIA MIG is the hardware implementation on A100 and H100.
- GPU Passthrough
- Giving a VM direct, exclusive access to a physical GPU by bypassing the hypervisor entirely. The VM sees the GPU as bare metal with no virtualization overhead. Maximum performance; the GPU cannot be shared.
- GPU Pooling
- Aggregating multiple physical GPUs across servers into a shared resource pool allocated dynamically to workloads. Rather than static per-server assignment, pooling lets the scheduler place GPU capacity where needed in real time - improving utilization and reducing idle hardware.
- Hypervisor
- Software that creates and manages VMs by abstracting physical hardware. In GPU contexts it enables GPU passthrough (direct VM access) or vGPU (shared access). Bare metal skips it entirely.
- Software-Defined GPU Virtualization
- An abstraction layer that decouples GPU resources from physical hardware through software, enabling dynamic pooling and multi-tenant sharing without hardware partitioning features like MIG. Pools multiple physical GPUs and provisions slices on demand, optimizing utilization across a fleet.
- Spatial Multiplexing
- Running multiple workloads on a GPU simultaneously by dividing SM (streaming multiprocessor) capacity spatially. More efficient than time-slicing for workloads that do not saturate the GPU alone - no switching overhead.
- Tenant Isolation
- Ensuring workloads from different users on shared GPU infrastructure cannot access each other's data or interfere with performance. Operates at multiple levels: memory (separate VRAM), compute (dedicated quotas), and network (separate VLANs).
- Time-Slicing (Temporal Multiplexing)
- A GPU sharing technique where multiple workloads take turns accessing the GPU in rapid rotation, each getting a time quantum. The GPU runs one workload at a time. Simple and broadly compatible, but workloads can interfere during context switches and memory is not isolated between tenants.
- vGPU (Virtual GPU)
- A software-defined slice of a physical GPU presented to a VM or container as a logical GPU device. Allows multiple tenants to share one card with isolation - each gets a portion of VRAM and compute.
- ECC Memory
- Error-Correcting Code memory - GPU VRAM that can detect and correct single-bit memory errors automatically, preventing silent data corruption during long training runs or large inference jobs. Enterprise data center GPUs (A100, H100, B200) support ECC; consumer cards (RTX 4090, RTX 5090) typically do not. For training runs lasting days or weeks, ECC matters - a single bit flip in a gradient update can corrupt an entire model without ECC catching it.
- GPU Autoscaling
- Automatically adding or removing GPU instances in response to real-time workload demand, without manual intervention. An autoscaler monitors queue depth, latency, or GPU utilization and provisions new instances when load increases, then terminates them when it drops. Critical for inference APIs and batch pipelines with variable traffic patterns.
- GPU Chargeback
- Allocating the cost of shared GPU infrastructure back to the teams, projects, or business units that consumed it, based on metered usage data. Common in enterprise and research environments where multiple teams share a GPU cluster. Requires accurate GPU metering as a prerequisite and a cost model ($/GPU-hour or $/token) to translate usage into charges.
- GPU Idle Time
- The portion of time a provisioned GPU spends with no active workload - compute utilization at or near zero while still consuming power and incurring cost. Idle time is the primary waste metric in GPU infrastructure. Causes include inefficient scheduling, workload queuing gaps, and jobs that hold GPUs between runs. Minimizing idle time is the core economic motivation behind dynamic GPU tiers and intelligent schedulers.
- GPU Metering
- Tracking GPU resource consumption at a granular level - per user, per job, per team, or per tenant - for billing, chargeback, or capacity planning. Metering captures wall-clock GPU time, VRAM usage, and compute utilization separately. Without metering, GPU costs are opaque and impossible to allocate accurately across teams or customers.
- MPS (Multi-Process Service)
- NVIDIA's CUDA feature that allows multiple processes to share a single GPU simultaneously by funneling their CUDA contexts through a single MPS server process. Unlike time-slicing (which switches between processes), MPS runs them concurrently on the GPU's compute resources. Better utilization for underutilizing workloads, but a crash in one client can affect all others sharing the same GPU.
- Resource Fragmentation
- The condition where GPU capacity exists across a fleet but cannot be efficiently allocated because available resources don't match workload requirements. Example: a fleet with 4x single free GPUs cannot serve a job requiring 4 GPUs on the same node with NVLink. Fragmentation is a core problem that intelligent schedulers like hosted.ai's haishare are built to solve.
- Spot Instance
- A GPU instance available at a steep discount (typically 50-80% below on-demand pricing) in exchange for the risk of interruption - the provider can reclaim the instance with little or no notice when demand spikes. Suited for fault-tolerant, checkpointed training jobs that can resume from the last saved state. Not suitable for latency-sensitive inference. packet.ai's Dynamic tier offers on-demand GPU access without interruption risk.
- Cloud Bursting
- Temporarily expanding capacity from on-premises or reserved GPU infrastructure into on-demand cloud instances when local resources are saturated. A training job that normally runs on owned hardware can burst to packet.ai Dynamic instances during peak demand, then scale back when done. Avoids the capital cost of sizing owned infrastructure for peak load.