PCI-E Question

Deonilin

Deonilin

Deonilin

Associate
Joined
12 Sep 2005
Posts
246
Location
Bristol-ish
Hi there, I currently have a ATI Radeon 4870 1GB in my system, I am planning on getting a PCI-E SATA RAID Controller (for more drive expansion!) which runs at 8x (so obviously it can go into one of the other 2 slots on the system), what I'm wondering is, is the graphics card going to be reduced to 8x speed? and will there be a big effect on performance etc? I'm not planning on running Crossfire at any time in the future to be perfectly honest.

Thanks
 
Last edited:
Without knowing the model of your motherboard this question is basically unanswerable. It'll depend on the total number of PCI-E lanes that are available and how the manufacturer has decided to allocate them.

Your motherboard manual should hopfully have a breakdown of the slot widths and available configurations.
 
its a P5Q-E but the manufacturer information doesnt seem to say much, it just mentions about using dual video cards in crossfire and going into 8x
 
The first two full length PCI-E slots share 16 PCI-E 2.0 lanes from the P45 north bridge, so if you use 8 lanes for a RAID controller you will drop the video card down to 8 lanes.

You may find that the RAID card works quite happily in the third full length slot. It only has 4 lanes but this is still more bandwidth than you'd have available from a PCI-X slot. These lanes are provided by the south bridge so they’ll have no impact on the other full length slots. This assumes you aren't using any of the x1 slots or the third full length slot will also drop down to a single lane.

You may also find that dropping the video card down to 8 lanes makes no noticeable difference.
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom