My graphics card is an nVidia GTS 450 which will only run two monitors at a time, but I'd like to add a third one. Will I be able to do that using a USB to DVI adapter or would the limit still be there? Also I've been told the video quality is really bad with these adapters, so is the quality of the video output by these adapters okay for things like web browsing and working on office thing? And is it worth the $60 or would I be better off just buying a cheep second card?


Everybody's needs and setup are different, but I'm using a USB-to-DVI device right now for a 3 monitor setup and it works great. Mine is a few years old, but it's basically the predecessor of this adapter. I don't think I'd game on it, but for work purposes the graphics are just like the other two monitors on my system, even for video.

  • Gaming I'll definitely keep on my graphics card powered monitors ;P this adapter is the one I was looking at, only because I can get one close to home without having to wait for shipping. I think I may go with the adapter you linked to though, I'm planning to use this to add an extra display to my desktop or laptop depending on what I'm using at the time. I'm just trying to decide now if I'll need three monitors on my laptop, or if two is fine. If two is fine, cheep second card is what I'll do haha. – CaffeinatedCM Jun 15 '12 at 15:13
  • I'm still confused as to whether or not the part of the asker's question about being limited to 2 monitors on his current video card was answered. My video card has an upper limit of two monitors output currently and I would like to know if the USB output somehow goes around that limit. – Reimius Feb 25 '13 at 20:47
  • Yes it does, because the USB output is its own video card. My system has a single discrete card in it that supports a max of 2 screens. I added the USB card and added a 3rd screen. The one I referenced in the answer is no longer available there, but similar ones still are. You can add several of those and get 4+ monitors all going at once, if you wanted. – techturtle Feb 25 '13 at 21:16

Unless you have a compelling reason not to add another card (for example a lack of suitable slots), the cheap second card would be a better idea.

The issue with USB video devices is the lack of bandwidth - they've often have been described as not being able to handle full motion video, but your mileage may vary.

If you intend to do mostly text, it may be an option. If you're doing say video, or stuff like that, the proper graphics card is a better idea. At equal cost or even slightly higher cost, the cheap video card would be my pick.

  • Would the cheep second card have negative effects on my current one if it's not the same GPU and memory types/speeds? – CaffeinatedCM Jun 15 '12 at 15:25
  • 5
    No, it should just run independantly. You only need a matching card for SLI – Journeyman Geek Jun 15 '12 at 15:28
  • Oh okay! Thank you :) I get so confused with all these google results when I try to search something. I'm definitely more of a software and code guy than a hardware guy. – CaffeinatedCM Jun 15 '12 at 15:31

Cheap second card if your system supports it. I used the cables, and they are terrible for anything that requires constant refresh. For emails and web browsing, it's perfect


Just to give some facts/figures here, a uncompressed full-HD stream is about 3 Gbit/s (at 60 fps). USB 2.0 has a theroetical peak of 240 Mbit/s in one direction.

So, a USB 2.0 adapter can't achieve full frame-rate. Even if compression and partial updates are possible, it won't be pleasant for watching hi-def movies.

Also note that these adapters seldom support 3D or probably even reasonable hardware accelerated 2D drawing, so most gaming is usually right out as well.

In my experience, drivers for these USB adapters can have very dubious quality. It's getting better, but if you can afford a cheap (used?) but proper GPU, go for it. (If it's the same brand/make as your primary card, it's probably a win to avoid compability issues)

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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