whats the difference between PCIEX16 & PCIEX4??

MJSBLUES

Honorable
May 7, 2013
360
0
10,810
Ok, the PCIe xXX is the amount of lanes the slot has. so x16 has 16 lanes, x8 has 8 lanes and so on.

The physical slot on x4, x8, and x16 are all the same.

If it says 2 PCIe x16 slots it means that there are 2 slots on the board that are capable of 16 lanes.

If it says 2 PCIe X16 (and then in brackets says x16, x4 or x8, x8) it means when you have 1 slot being used it uses all 16 lanes for that 1 slot. But if you plug multiple things into the PCIe slots (most common 2 GPU's) it will divide the lanes between the cards. So that (x16, x4) you will have the first GPU running with 16 lanes, and the second GPU running with 4 lanes.

The manual for any board is going to say what the slot is at natively (x16, x8, x4) and how it reacts if in SLI (multiple GPU's)

For GPU's most of the time there is not much difference between 16x and 4x because GPU's can not fully saturate the bandwidth of the slot, therefore it is hardware limited, not bus limited.

But still, plug it in x16.
 

No.



Depends on how much bandwidth the card requires. If a PCIe card only requires PCIe x1 and you plug it into x16, it will still work but you gain no increased performance.



PCIe x16.
 

manish_mv

Distinguished
Oct 27, 2013
2
0
18,510


Hi

I have bought gigabyte ga-z77pd3 MB

http://www.gigabyte.com/products/product-page.aspx?pid=4148#sp

1 x PCI Express x16 slot, running at x16 (PCIEX16)
(The PCIEX16 slot conforms to PCI Express 3.0 standard.)
* For optimum performance, if only one PCI Express graphics card is to be installed, be sure to install it in the PCIEX16 slot.
* The PCI Express x16 slot supports up to PCI Express 2.0 standard when an Intel 32nm (Sandy Bridge) CPU is installed.
1 x PCI Express x16 slot, running at x4 (PCIEX4)

now i have 2 video cards

1. leadtek gtx 460
2. xfx 8400gs

2nd one is about 4 yr old card and 1st is new and MoBo is newest.

The query (problem) is that neither of card is running on the second pciex4 slot.

Any help in this regard is greatly appreciated.

Thanks
Manish
 

ZigiZago

Reputable
Jul 7, 2015
7
0
4,510
I want to use CrossFire (i will buy cards soon), so both has to have a slot right? Do i need 2 x16 3.0 slots then? Because the most mother boards dont have that!