I have the following cards

GTX 1650 - new in box
GTX 1060 - in my i9 12900k MS Windows 11
GTX 950 - in an old Win 10 machine that can be cannibalized.
Quadro FX 1500 - in my 10th gen i3 Linux - kernel 5.15.19 (slackware 15)

The Quadro card is failing and throwing a lot of geometric artifacts, pretty sure its not the cable or monitor as both have been used on several machines and os's without issue in recent times.

The 1060 provides acceptable performance as is, so I'm considering putting the 1650 in the Linux machine, but will I be able to run the x11 Plasma 5 KDE thing with that card? I'd like to not waste a bunch of sweat if it is already known that nouveau won't support the 1650. (not for gaming, so speed isn't all that critical..)

I could fall back to putting the 1060 in the linux machine and trading out to the 1650 for the windows machine... But I'd like to not mess with the windows machine if I can avoid it. I'm happy with the way it performs already.

Would the 950 be a better bet for the new Linux machine?

Which way should I go with this for stability and least amount of sweat equity?

I'd use the newest card GTX 1650 and install the latest nvidia driver from the .run script,
replacing the nouveau driver. Nouveau is cool, and I am glad it is there but i get
better performance from the nvidia driver, blob and all, and the nvidia driver works great with the updated KDE provided by 15.0/-current.

1 members found this post helpful.

While it is true that being built-in to the kernel nouveau and AMD GPUs are easier, and it's also true that a lot of folks bitch and moan about Nvidia not being FOSS, but the fact remains that Nvidia has had a long-standing policy of decent support for numerous "alternative" OpSys, even OS/2 and BeOS. My current best GPU is a GTX 1070 Ti and it's getting rather long in the tooth (when will this GPU crunch end?) but I'm an avid gamer and I keep several games and benchmark apps on an NTFS partition so I can compare performance in Linux vs/ Windows. In all but a few cases my GPU performance is better on Linux, and in some cases, substantially better, like over 20%.

Just for example, on the Shadow of the Tomb Raider benchmark, with exactly the same feature settings excepting Win10 has a DirectX-12 button enabled, my average FPS on near Ultra is 67 FPS. On Slackware, same settings but possibly hindered some by ntfs, my average FPS is 96. Nvidia may have gotten a bit bully-like of late, but they're still OK in support and performance.

Went with the 1650 for the Slackware machine and its working like a champ, even with using the nouveau driver. Its been many years since I've had an x-windows workstation hooked up with its own local display. Most of my recent Linuxes being headless, slackwares in a server only role.

Should be interesting to mess with.

Especially since you're not gaming (or CAD work?) the 950 seems the most available and should do a fine job. FWIW the proprietary nvidia driver is the same for all 3 GT cards and will probably work on the Quadro as well, so you could swap cards and see what you like best for your workflow. FWIW I have a box with an old GT 640 that operates just fine at 1080p. Another with a GT 760 will do 2K resolutions. The 950 should be quite adequate.

Thanks for the feedback. I may swap the 950 machine to slackware as-is. But the new machines are just so much more capable that I could end up retiring the older pair and just letting the two new machines handle my whole work-flow/process. They replaced a pair of HP Z800 (dual xeon) workstations and a lower end xw4400 that I'd gotten off ebay. All came with Quadros, fwiw.

I mostly do software development and testing (both windows and linux) with my little home mini-lab.

Nice! Quadro cards are quite impressive for the niche they were designed for, despite that, as I understand it, there is very little difference in some models. I recall a mod involving a couple resistors, possibly a trace interruption, and a bios flash and bam! FX became Quadro. I have an ancient (2007) T61 Thinkpad with a mobile Quadro that easily handles 1080p and is still supported (take THAT AMD!) I replaced the display panel with an IPS model from a T60 I bought for 30 bux off eBay. It said "Parts Only" but with just a wee bit of tweaking it runs fine so now I have an old laptop I don't need LOL. The IPS looks amazing with the Quadro. Other than the flat panel, the T61 is a huge improvement - much more RAM, far more CPU options (it's socketed) easily upgradeable to any wifi chip, and a community BIOS flash doubled RAM capacity and activated SATA v2.

Anyway, it sounds like you have things well under control. Congratz!