I cannot turn that resizable bar feature on in my gigabyte desktop that I am currently using, nor the 4g decoding option which was on my z690 gigabyte master motherboard that broke, but my current older desktop, its bios doesn’t support either, but the 3D card works fine mostly without that support, I think it improves the 3D games a bit if you can turn it on under windows 11, but I don’t know about Linux, as I never seen the resizable bar feature show in NVidia config or NVidia settings app under Linux, so I don’t know if kde plasma or gnome versions support it at all, it might just be a windows feature of the NVidia 3D cards. The 3D gigabyte NVidia RTX 3070 master card supports it, but I have in the gigabyte G1.Assassin 2 (rev. 1.0) motherboard does not support the resizable bar feature at this time, as the F12w bios from Oct 30, 2013 does not include 4g decoding or resizable bar settings in the dual bios, that desktop is using ddr 3 memory, so even if I could turn it on, I am not sure it would improve the 3D cards gaming in that desktop, Additionally, it is equipped with an Intel i7 processor, which prevents overheating unlike the Intel i9 series that requires liquid cooling that I have in my newer Alienware r16 pc is a intel i9 processor, which has a liquid cooling based fan on it, but my older G1.Assassin 2 desktop fans are not liquid based at all, and that’s what I have bazzite Linux on at this time. the gigabyte G1.Assassin 2 desktop still works just fine for linux but again its been years since the last firmware update was released for it, so even thought the 3D card is a lot newer the resizeable bar feature may not work in this older desktop that I put it in, which is what seems to work fine with hdmi only with bazzite nvidia image plasma kde version of bazzite nvidia deck steam. the display port had a problem in sleep mode, when it waked up it got no signal problem with monitor, but the hdmi seems to wake and get a display again, so that problem I did fix with the 3D card that supports resizeable bar which again is set to no on my gigabyte desktop. otherwise I have no problem with it, I did once have a radeon 3D card amd based I think but it failured me years ago, since then I have sticked with nvidia and intel based hardware, as I never owned an amd processor I am not sure but if I remember some video games didn’t like it, from what I read online, I seen them in stores, but I been unsure about how, well it preforms compared to the intel processor, has it worked well for you?
as I don’t know if the linux nvidia drivers support it at all, hopefully someone else can answer this question for you, but as far as I can tell there is no information under linux in the nvidia settings app about the resizeable bar , its turned on in my alienware r16 pc but again that running on windows 11 still, as I don’t plan on switching my newer desktop to linux, I cannot answer that question fully.