all about PCI express

guys, i heard about the PCI express x16 slot that we most commonly used to video card.

my question is what are the other PCI x1, x2, x4 and x8 used for? (these are PCI's found on Mobo's and i want to know what they are there for)

thanks.

hi , i know they are expansion slots but my question is what they are for. Like is the PCI x1 for sound card or LAN Card?

all i know is pci x16 & AGP 8x is for video cards.

but thanks for the reply.

i appreciate it.

No, its not. First of all, the slot has more bandwidth than all the other PCI slots (on consumer-level motherboards) combined. Second, its much smaller. Third, its serial rather than parallel in its connection to the controller chip. This is the same for every PCI-E slot, its just that the other designations have more "lanes", thereby producing proportionally more bandwidth, i.e. x16 (theoretically) produces 16 times the bandwidth than x1.

Now for the other slots. All can be used for general purpose. If it will fit the slot, it will work. As far as I can tell, it is possible to plug in an x1 card into an x16 (why?) slot and it will work. I believe it was toms that did an article when PCI-E was first coming out about how you could tape off the contacts on a PCI-E x16 card and have it perform as an x8, x4, x2, or x1. It just depends on what the manufacturer deems is needed for the card.

The uses? Well, for anything less than x16 I have seen (because I went a'huntin a couple weeks back) USB/Firewire, SATA, Gigabit Ethernet, Video, and most recently SCSI controllers. Most of those were for x1, but the SCSI controllers were x8. Oddly enough, there's no sound cards out for PCI-E yet, I heard it was something about how noisy the interconnect is (didn't research it, discussed here.).

The reason these things aren't well known is because PCI-E is still transitioning to be the "mainstream", just like PCI and ISA before it. Granted, those legacy busses will remain in the computer, just a much less visible part. No slots, just interconnects for things like sensors and onboard components. Soon enough, PCI will be gone from public view and PCI-E and all its flavors will dominate the normal computer slots.

But be sure to know that PCI-E is not PCI. It may have a similar name, but they are two very different animals. They are not compatible with each other and you will destroy something if you try to force one into the other.

Peace.

thanks for that input guys!

Nope, completely different.

thanks guys,

just wondering, from your feedbacks, im getting that most of these ports (like PCIe 4x & 8x) are very seldom used?

if yes, why are so many Mobo with these ports build in?