My basic Question is as the title says will having a Radeon 4890 in a X16 PCI Express 1.0 slot hold it back significantly compared to a 2.0 x16 slot and if so are we talking 2% or 50%? Read below if you want the story as to why I am asking and I would welcome further comments on this.
My brothers motherboard died the other day and he wants a very cheap upgrade to last until bulldozer and sandy bridge are out so I recommended he gets a Asrock N68C-S UCC AM2+ board (only £36.99) and an Athlon X3 440 and keeps his 2GB DDR2 RAM (he's running 32bit Windows XP) and the rest of his current components. Also I offered to swap my 4890 with his 4870 and I would buy another to run Crossfire in my PC. Does this sound like a senseable thing to do?
I just read a thing on it here at toms. Like jefe323 says, PCIe 1.0 is half of 2.0 speed wise, so it's equivalent to PCIe 2.0 x8. In the benchmarks I just saw, the difference between 16x and 8x (on PCIe 2.0) was only 4%.
While the bandwidth of pcie 2.0 is higher, current video cards do not use all of 1.0. It is only when you get into dual and triple Highest end cards does the speed limitation show up.
Even then, It is not a significant difference.
If you are interested in gaming, spend your funds on your graphic configuration and not the cpu. Sandy bridge and bulldozer will not bring much more to the table than current products if you match them with a good vga card/s.
I suggest he get a motherboard he can live with for some time up front. Sell all the old parts that can't be carried over.