Linux: How to Check Graphics Card Memory

List all the PCI devices: lspci

# Sample Outout:
root@kim-linux:/home/kim# lspci
00:00.0 Host bridge: Intel Corporation Device 3ecc (rev 08)
00:02.0 VGA compatible controller: Intel Corporation Iris Plus Graphics 655 (rev 01)
00:08.0 System peripheral: Intel Corporation Xeon E3-1200 v5/v6 / E3-1500 v5 / 6th/7th/8th Gen Core Processor Gaussian Mixture Model
00:12.0 Signal processing controller: Intel Corporation Cannon Point-LP Thermal Controller (rev 30)
##### Truncated for brevity #####

Get information only on the VGA device

vgaDevice=$(lspci|grep VGA)
vgaDeviceId=$(echo "$vgaDevice" | grep -Eo '^[^ ]+')
lspci -vs $vgaDeviceId

# Sample Outout:
root@kim-linux:/home/kim# lspci -vs 00:02.0
00:02.0 VGA compatible controller: Intel Corporation Iris Plus Graphics 655 (rev 01) (prog-if 00 [VGA controller])
DeviceName: CPU
Subsystem: Intel Corporation Iris Plus Graphics 655
Flags: bus master, fast devsel, latency 0, IRQ 134
Memory at af000000 (64-bit, non-prefetchable) [size=16M]
Memory at 40000000 (64-bit, prefetchable) [size=1G]
I/O ports at 4000 [size=64]
Expansion ROM at 000c0000 [virtual] [disabled] [size=128K]
Capabilities: [40] Vendor Specific Information: Len=0c <?>
Capabilities: [70] Express Root Complex Integrated Endpoint, MSI 00
Capabilities: [ac] MSI: Enable+ Count=1/1 Maskable- 64bit-
Capabilities: [d0] Power Management version 2
Capabilities: [100] Process Address Space ID (PASID)
Capabilities: [200] Address Translation Service (ATS)
Capabilities: [300] Page Request Interface (PRI)
Kernel driver in use: i915
Kernel modules: i915