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That is the whole point, one of the original use cases was passing around buffers between different GPUs on dual-graphics laptops (PRIME)
by floatboth 7y ago
That is the whole point, one of the original use cases was passing around buffers between different GPUs on dual-graphics laptops (PRIME)
- ambrop7 7y agoDo you maybe know, when frames rendered by GPU 1 (e.g. fast GPU) need to be sent to GPU 2 (e.g. slow GPU doing the compositing and outputting to the monitor), how does the data actually get transferred? I can imagine the following possibilities: 1) GPU 1 writes to CPU RAM, GPU 2 reads from CPU RAM 2) GPU 1 writes to GPU 2 RAM via PCI Express (DMA between devices) 3) GPU 2 reads from GPU 1 RAM via PCI Express (DMA between devices)
- zlynx 7y agoAFAIK, GPU 1 writes directly to GPU 2 via PCIe. Since GPU 2 is most often an Intel iGPU, that happens to also be CPU RAM.