Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Possible Duplicate:
Does a x4 PCIe mechanical work in a x16 slot in x4 mode?

I know I can place a smaller card in a larger slot. But can I be 100% certain that it works? (if we ignore a broken card or broken slot)

share|improve this question

marked as duplicate by Ƭᴇcʜιᴇ007, bwDraco, grawity, Mokubai, random Dec 11 '11 at 23:03

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

It's slightly different though. Are there any cases where it won't work if you put a smaller card in a larger slot? – Simon Verbeke Dec 11 '11 at 18:43
Smaller cards are intended to be used in larger slots, as part of the PCIe specification. (a 1x card can fit, and operate, in a 1x, 4x, 8x or 16x slot). I'm not sure why you think the linked question is different, he also wants to know if a 4x card will work in a 16x slot, and run at 4x. :) – Ƭᴇcʜιᴇ007 Dec 11 '11 at 18:48
Alright, this can be closed then. I though that maybe in some special cases there might be a problem. – Simon Verbeke Dec 11 '11 at 18:53
Moreover you can get motherboards with x16 physical slots and less (x8, x4, x1) electrical connectivity. This will also work. Of course if you put a graphics card in such a slot the performance will be poor! – Ben Jackson Dec 11 '11 at 22:11
up vote 15 down vote accepted

Yes, a PCIe x4 card will function in a PCIe x16 slot. The slot will simply use 4 of the 16 lanes available, and the card will work properly. See Wikipedia for more details.

share|improve this answer

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