how to tell which pciE slot runs at x16 and which at x8?

Question

Hello, i've recently been looking at a new motherboard to run crossfire on and i was wondering how i could tell which slots run at x16 and which at x8. I'm pretty sure that the board i'm looking at has two x16 slots, however i don't exactly trust asus to tell me whether or not it does at the moment. the board i'm looking at is this: http://ca.asus.com/en/Motherboards/AMD_AM3Plus/SABERTOOTH_990FX/#specifications

just want to know this because of case size. I'll be putting two 6950's on it if i decide to buy it. Also a second question (might sound stupid) will i have to buy windows again or am i able to re-use my old copy? is windows installed directly on your motherboard or does it run off of your hdd. This will be the first time i've had to setup a motherboard, so i really don't want to mess it up somehow (it is rather expensive).

Answer 1

First: speeds depends on the motherboards specs. If you don't trust ASUS the manufacturer to provide the correct specs, then don't buy the board, duh.



Normally SLI/Crossfire board with multiple PCI-e x16 slots will tell you the speeds they run at (dual x 16, one at x16 and one at x8, or two at x8..... and so on).



Generally for a dual PCI-e x16 board you'll either have both running in x16 mode, or the first in x16 and the second in x8 mode.



Usually the FIRST slot will run in x16 mode. This should the the one that's the highest up, or the one closest physically to the CPU. Consult your motherboards manual for more information though, since it may not be as I said.



And as for the OS question, yes, if you get a new HDD you'll need to install a new copy onto it. If you're using an old HDD with the new motherboard you'll want to do a fresh re-install of Windows and install the motherboards drivers if you got a CD/DVD for them. Normally the OS is contained on the hard drive (HDD or SSD), you can boot from a network, USB, floppy drive, or CD/DVD too, but normally you'll boot from the hard drive, unless you need to install Windows, in which case you'll choose to boot from the CD containing your copy of Windows 7.



Good luck :D

Answer 2

pcie 2.0 slots can carry extra present day video playing cards a 2.0 card will paintings in a reg x16 slot however it wont be as quickly so in case you may improve the mummy board which may be the staggering flow...or construct a clean pc for sure

Answer 3

Yes, it has 2 PCI-e 16x slots. No need to worry.