a friend of me just bought an HD 3870 to an old system. according to ati ccc, gpu-z and rivatunre, the card only runs at 4x pci express.
he have a gigabyte 945gz, mobo p4 3.0 (631) processor and 512mg running at single channel.
he's getting very playable frame rates at cod4 at 1280*1024 with 4x aa but crysis and bioshock gets very low frame rates .. ( i think this is due to the memory limitations, right ?)
any way .. i didn't find anything in the bios about changing it to 16X neither did i find anything in the mobo catalouge or in the website refering to this mobo havin a 16X pci express in the 1st place (advertised only as pci express)
could it be that this mobo doesn't have 16 lanes for pci-e ?
will upgrading the mem to 2 gigz at dual channel put everything in it's right place ??
My suggestion would be to buy a inexpensive P35 motherboard a E2180 and 2x1gb DDR2 which can all be had for around $200USD. Doing this will allow your friend to either overclock or give him an upgrade path rather than putting money into a dead end.
As wolf shows, not ALL 16x physical slots run at 16x. there are a lot out there that run at 8x (most of the lower end sli setup), 4x (as the one pointed out by Wolf) for a single, or 4x for the 2nd crossfire slot.
Wolfshadow .. u're right this is the mobo he has , big dissapoinment that this wasn't clear when he bought it ..
jaywalker .. i remember the test u r talkin about , but i also remember in some thread somebody mentioned playin crysis well on a p4 , 2 gigz and a 8800gt,
that wht made me think of the memory being the big bottleneck. specially that those games (crysis and bioshock and even HL2) take very long load times and are very slow when they first start up (like 2 fps or something) ..
after a while they get better (18 - 23 fps for crysis @ 1024*768 high setting). but still speeds on then slows down.
ausch30 .. it's DDR 2 and the board supports dual core processors , even c2d but with lower FSB .. but u're right investing in a p35 would be a better decision