GPU VRAM Bandwidth & Bus Bottleneck Calculator
Analyze effective memory bandwidth across GDDR6, GDDR6X, and GDDR7 architectures. Diagnose memory bus width limits (128-bit vs 256-bit vs 384-bit) at high resolutions with Ray Tracing.
โ๏ธ GPU Hardware Specs
Large L2 cache (Ada Lovelace 32-96MB) and AMD Infinity Cache (64-96MB) multiply effective memory bandwidth by reducing memory bus roundtrips.
๐ Throughput Analysis & Headroom
Your 256-bit bus with 21 Gbps memory delivers 672.0 GB/s raw bandwidth. Supported by 64MB of on-die cache, this GPU exhibits zero memory pipeline choking at 1440p and maintains high 1% low frame time stability in heavy Ray Traced titles.
๐ Why Memory Bus Width & VRAM Bandwidth Matter in Gaming
While graphics card marketing frequently highlights total VRAM capacity (e.g. 8GB vs 16GB), the Memory Bus Width and VRAM Bandwidth (GB/s) determine how quickly the GPU core can read texture maps, z-buffers, shadow maps, and Ray Tracing BVH (Bounding Volume Hierarchy) acceleration structures.
128-Bit Narrow Bus Bottlenecks
Common on entry-to-midrange cards (e.g., RTX 4060, RX 7600). Adequate for 1080p, but when moving to 1440p or 4K, texture mipmaps exceed the small on-die L2 cache, resulting in severe 1% low frame drops and stuttering.
L2 & Infinity Cache Scaling
NVIDIA Ada Lovelace expanded L2 cache up to 96MB, while AMD uses up to 96MB of Infinity Cache. High cache hit rates (60-80%) reduce trips over the physical memory bus, effectively boosting apparent throughput by 1.4x to 2.2x.
GDDR7 vs GDDR6X Jump
GDDR7 introduces PAM-3 signaling (3 bits over 2 cycles), allowing pin speeds of 28 to 36 Gbps. Even with a 256-bit bus, GDDR7 reaches over 1,150 GB/s raw bandwidth without requiring massive power draw.