Python3用WMI读取GPU显存错误，如何获取N卡/AMD/Intel卡正确显存？

Win32_VideoController的AdapterRAM字段存在先天设计缺陷，它使用32位无符号整数存储显存大小，最大值仅为4294967296字节（即4GB），只要显存超过4GB就会返回错误值，和显卡品牌无关，是WMI接口本身的问题。

Windows环境下直接调用原生DXGI接口是最优方案，该接口是Windows官方提供的图形设备枚举接口，所有NVIDIA、AMD、Intel显卡都原生支持，返回的显存数值和任务管理器、dxdiag完全一致。

方案1：仅用Python标准库实现（无额外依赖） #

通过ctypes直接调用DXGI接口，无需安装第三方包：

import ctypes
from ctypes import wintypes

class LUID(ctypes.Structure):
    _fields_ = [
        ("LowPart", wintypes.DWORD),
        ("HighPart", wintypes.LONG),
    ]

class DXGI_ADAPTER_DESC(ctypes.Structure):
    _fields_ = [
        ("Description", wintypes.WCHAR * 128),
        ("VendorId", wintypes.UINT),
        ("DeviceId", wintypes.UINT),
        ("SubSysId", wintypes.UINT),
        ("Revision", wintypes.UINT),
        ("DedicatedVideoMemory", wintypes.SIZE_T),
        ("DedicatedSystemMemory", wintypes.SIZE_T),
        ("SharedSystemMemory", wintypes.SIZE_T),
        ("AdapterLuid", LUID),
    ]

dxgi = ctypes.WinDLL("dxgi.dll")
dxgi.CreateDXGIFactory.argtypes = [ctypes.POINTER(wintypes.GUID), ctypes.POINTER(ctypes.c_void_p)]
dxgi.CreateDXGIFactory.restype = wintypes.HRESULT

IID_IDXGIFactory = wintypes.GUID("{7b7166ec-21c7-44ae-b21a-c9ae321ae369}")

def get_gpu_memory():
    gpu_list = []
    factory = ctypes.c_void_p()
    hr = dxgi.CreateDXGIFactory(ctypes.byref(IID_IDXGIFactory), ctypes.byref(factory))
    if hr < 0:
        return gpu_list
    i = 0
    while True:
        adapter = ctypes.c_void_p()
        enum_adapters = ctypes.cast(factory, ctypes.POINTER(ctypes.c_void_p))[0]
        enum_adapters = ctypes.cast(enum_adapters + 3 * ctypes.sizeof(ctypes.c_void_p), ctypes.POINTER(ctypes.CFUNCTYPE(wintypes.HRESULT, ctypes.c_void_p, wintypes.UINT, ctypes.POINTER(ctypes.c_void_p))))[0]
        hr = enum_adapters(factory, i, ctypes.byref(adapter))
        if hr < 0:
            break
        get_desc = ctypes.cast(adapter, ctypes.POINTER(ctypes.c_void_p))[0]
        get_desc = ctypes.cast(get_desc + 8 * ctypes.sizeof(ctypes.c_void_p), ctypes.POINTER(ctypes.CFUNCTYPE(wintypes.HRESULT, ctypes.c_void_p, ctypes.POINTER(DXGI_ADAPTER_DESC))))[0]
        desc = DXGI_ADAPTER_DESC()
        hr = get_desc(adapter, ctypes.byref(desc))
        if hr >= 0:
            gpu_list.append({
                "name": desc.Description,
                "dedicated_vram_bytes": desc.DedicatedVideoMemory,
                "dedicated_vram_gb": round(desc.DedicatedVideoMemory / (1024**3), 2)
            })
        release = ctypes.cast(adapter, ctypes.POINTER(ctypes.c_void_p))[0]
        release = ctypes.cast(release + 2 * ctypes.sizeof(ctypes.c_void_p), ctypes.POINTER(ctypes.CFUNCTYPE(wintypes.ULONG, ctypes.c_void_p)))[0]
        release(adapter)
        i += 1
    release = ctypes.cast(factory, ctypes.POINTER(ctypes.c_void_p))[0]
    release = ctypes.cast(release + 2 * ctypes.sizeof(ctypes.c_void_p), ctypes.POINTER(ctypes.CFUNCTYPE(wintypes.ULONG, ctypes.c_void_p)))[0]
    release(factory)
    return gpu_list

if __name__ == "__main__":
    gpus = get_gpu_memory()
    for gpu in gpus:
        print(f"显卡名称：{gpu['name']}")
        print(f"独立显存大小：{gpu['dedicated_vram_gb']} GB\n")

方案2：使用封装好的第三方库简化调用 #

如果可以安装第三方依赖，直接用封装好的dxgi库即可，代码更简洁：

1. 先安装依赖：pip install dxgi
2. 调用代码：

from dxgi import DXGI

dxgi = DXGI()
for adapter in dxgi.enum_adapters():
    desc = adapter.get_desc()
    print(f"显卡名称：{desc.description}")
    print(f"独立显存大小：{round(desc.dedicated_video_memory / 1024**3, 2)} GB\n")

• 以上方案仅适用于Windows系统，DXGI是Windows独有的图形接口
• 如果需要跨Linux、Windows平台适配，Linux下可以通过读取/sys/class/drm/节点获取显存信息，同样兼容全厂商显卡

内容的提问来源于stack exchange，提问作者Olaf Zhang