This is, in a way, more of a hypothetical question, not something I'm seriously considering, but I am curious to know how feasible or useful it would be.

The scenario is: The computer has a graphics card with 4GB of RAM in its PCIEX16 slot, as normal. Since the CPU is a Xeon, it has no graphics chip, and therefore the graphics card is the only graphics hardware in the computer.

It would be useful to use the graphics card for video editing (using video editing software that can take advantage of the gpu). At least in Linux, about 600MB of that RAM is already reserved by the system (for unknown purposes). This is a very considerable chunk of the 4GB.

The motherboard also has a free PCIEX4 slot.

Would it be in any way feasible to purchase an ultra-cheap junk graphics card and put it in that PCIEX4 slot, and have the OS run using it, which would ostensibly leave 100% of the big gpu for the video editing software? (Obviously this junk gpu would only be used for desktop usage, not eg. gaming or anything.) Would there even be any real benefit?

Note that the display, and thus the desktop environment, has 4k resolution, so the system must be able to run fluently at that resolution. (Things like running 60FPS 4k full-screen video ought to be possible.)

  • That's an interesting question. Re your last paragraph, Intel's integrated GPU in Core processors can handle 4k@60fps flawlessly, so any relatively recent GPU will too. – gronostaj Jul 11 '18 at 7:12
  • I'm not so much worried about an ultra-cheap gpu being able to run a desktop (and eg. video) at 4k. I'm more worried about the speed of that PCIEX4 slot. Is it enough to eg. show 4k video at 60 fps? (I freely admit I don't know what kind of data transfer is required from the hardware when playing a 4k 60fps video.) Could the x4 speed (compared to the normal x16) become a bottleneck? – Warp Jul 12 '18 at 10:41
  • 1
    I couldn't find up-to-date benchmarks, but x4 should be sufficient. Here's a 2012 forum thread in Polish. Interesting parts: PCI-E2.0x4 vs PCI-E2.0x16 in gaming benchmark, some PCI-E3.0 benchmarks. I guess PCI-E 3.0 x4 would still suffice for 4k@60fps for non-gaming usage because there's much less VRAM action going on. – gronostaj Jul 12 '18 at 10:56

Feasable: Yes.
Worth the money: possibly not.

I do not expect a significant speed gain unless the software you are using is puching the memory limits on your current card.

If it is then adding a second graphics card in another slot would indeed free up resources, and PCIE x4 slot is not a problem. You probably loose up to 5% speed, but even 95% speed on a semi recent ultracheap graphics card should be plenty for non gaming).

Thus to answer your question (title): Using a graphics card on a PCIEX4 slot
Yes, that certainly works.

But to answer what I suspect that you want to ask: Will it be useful?
Probably not.

Check how much memory is used by your video editing software. If that never uses the remainging of the 4GiB then I expect no significant gain. If it always tries to use way more than 4GiB and yopu might see a very small gain. And only if you are lucky enough that the difference between what it wants to use wand what you free up matches than you might have a noticeable gain.

Your Answer

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.

Not the answer you're looking for? Browse other questions tagged or ask your own question.