Syllo
The memory usage displayed by `nvtop` is different from that of `nvidia-smi`
I noticed that on my platform (Ubuntu 24.04, RTX3060), when it comes to VRAM utilization, nvtop gives a different number to nvidia-smi
I noticed this when I was writing a C program which needs to get VRAM usage of Nvidia GPUs. I used the following code and get the same result as what nvidia-smi shows. However, I'm not sure whether it takes all VRAM utilization into account and which program (nvtop/nvidia-smi) shows the real utilization.
By the way, in most cases nvtop shows larger VRAM utilization than nvidia-smi.
UINT32 nvidiaUsedVram(void) {
size_t freeMemory, totalMemory;
cudaMemGetInfo(&freeMemory, &totalMemory);
return (totalMemory - freeMemory) / (1024 * 1024);
}
I face the same problem. After my os upgraded to 24.04, the dispaly of nvtop is no longer correct even I update the nvtop to 3.0.2-1.
Hard to say which one is closer to what we can expect as "allocated memory". Nvtop uses the result of nvmlDeviceGetMemoryInfo_v2 coming directly from the driver!
The value nvtop displays is the used memory: Allocated device memory (in bytes).
Perhaps nvidia-smi subtracts the reserved memory? I'm not sure.
Hard to say which one is closer to what we can expect as "allocated memory". Nvtop uses the result of nvmlDeviceGetMemoryInfo_v2 coming directly from the driver!
The value nvtop displays is the used memory: Allocated device memory (in bytes). Perhaps nvidia-smi subtracts the
reservedmemory? I'm not sure.
Not sure either, since both methods are offered by nvidia.
I have been having the same issue recently on Arch, where nvidia-smi reports 0 but nvtop stubbornly says the machine's using "0.375Gi/7.996Gi" while idle.
nvtop: version 3.2.0 nvidia drivers: Driver Version: 580.76.05 & CUDA Version: 13.0 GPU: NVIDIA GeForce RTX 4060 Mobile GPU
