Not enough pci express lanes to go around

[winterwatchers]

I have gigabyte p35 dq6 board.

I read somewhere that intel p35 chips have only 22 express lanes.

I already have a graphics card x16 and a areca 1210 raid x8 controller card installed and I just bought a 1x sound card. The sound card only works when the areca card is pulled out because otherwise the areca would automatically take up the rest of the remaining 6 lanes available.

I had the areca installed into the second physical x16 slot which according to the intel and gigabyte documentation; its only supposed to support up to x4 lanes and no more. But somehow the board will assign more lanes to it then specified.

This is BS. Why do manufacturers even put the 1x slots in if they are not even useable because they don't dedicate specific PCI express lanes to them. and what is even worse is that on alot of board there are 3 x1 slots and if you were suppose to fill up the 2 x16 slots there wouldn't be any express lanes left for the x1 slots. They should clearly state this!!!!

So to summarize if you have intel p35 NB chips, be very careful when buying express tv tuners cards, sounds cards, etc.

 

[PCTC2]

There is clearly 2 lanes left after the 2 x16 slots. The top slot acts in x16 and the next slot works in x4. It may be x16 physically but it's x4 electrically. PCIe is made to be compatible in both directions AS LONG AS it fits physically. It just means it won't have as much bandwidth available to it. You clearly, after 16+4, have 2 left for your sound card. Just figure out which of the x1 slots are disabled when your two x16 slots are occupied.

 

[winterwatchers]

That's what I was trying to say in the first thread. None of the 1x slots work after filling in both the x16 slots( one electrically 16, one electrically 4). The 1x slot only work after I take out the bottom x16,electrically x4 slot

 

[Rifter]

i dont own an intel chipset so forgive me if this is wrong, however if the chipset provides only 22 pci-e lanes is that for the physical slots or the whole board? the reason i ask is the onboard USB controller, NIC, sound, SATA controller etc might be on the pci-e bus as well and useing some of the 22 lanes.

 

[winterwatchers]

interesting point, and to answer that I don't think so. The p35 block diagram displays them as separate from express lanes and it makes sense because USB controllers sent and receive signals differently from PCI-e

 

[tcsenter]

RTFM:

(Note 2) When the second PCI Express x16 slot (PCIE_16_2) is in use, the three PCI Express x1 slots become unavailable.

 

[Heidfirst]

Originally posted by: winterwatchers
interesting point, and to answer that I don't think so. The p35 block diagram displays them as separate from express lanes and it makes sense because USB controllers sent and receive signals differently from PCI-e

the nic is on th pci-e bus

 

[winterwatchers]

Thank you tcsenter. "----(Note 2) When the second PCI Express x16 slot (PCIE_16_2) is in use, the three PCI Express x1 slots become unavailable.-------" I guess this serves as a valuable lessen to always RE-check the manual for major hardware component before buying something.

When I first bought the mobo, I didn't foresee this would happen.

ok, the only solution left is to buy another mobo. I am currently looking at this one

http://www.newegg.com/Product/...x?Item=N82E16813128358

The block diagram I read about here at anand saids that one pciex16_1 slot is running at 16x electrically, but if the pciex16_2 slot is also used, the channel is split and both becomes x8 electrically.

Now my question is will I be able the use x16_2 for something other than GPU like my areca raid controller card? How will that effect the x16_1 slot? I am asking because it seems this two x8 configuration is made specifically for Crossfire.

Also will I still be able to use the 3 pciex1 slots?