SLi 2 x16 Vs 1 x16 & 1 x8

[Boff_in]

ok, So I'm looking to upgrade from 775.

Looking at Sandybridge Mobo's most only have 1 x16 PCI-e slot. I would have to go 1366 to get 2 x16 slots and spend a lot more money.

My question is regarding performance of SLi.
Regarding playing games, is there a performance hit when SLi with 1 x16 & 1 x8 over having 2 x16 slots?

Any feedback is great,
Boff

 

[ThomasTheTankEngine]

There's a tiny performance increase with 16x16x over 16x8x.

Perhaps 5% better performance at the most. Nowhere near worth the extra you'd have to pay for 1366 (or the most expensive 1155 boards).

My board doesn't do 16x16, but I get the same numbers on benchmarks as people with much more expensive 1366 systems.

 

[lay-z-boy]

It depends on what your doing. Throw some high resolution, aa and complex visuals into the mix and you can see drops around 10% (worst case I've seen). Usually it's anything from 0-4% though.

Sandy bridge doesn't do 16x/8x anyway, it can only do 8x/8x. This takes it up to about 3-7%. Avoid bridge chips however (nf200), they add an extra 2% due to the switching.

 

[ThomasTheTankEngine]

It depends on what your doing. Throw some high resolution, aa and complex visuals into the mix and you can see drops around 10% (worst case I've seen). Usually it's anything from 0-4% though.

Sandy bridge doesn't do 16x/8x anyway, it can only do 8x/8x. This takes it up to about 3-7%. Avoid bridge chips however (nf200), they add an extra 2% due to the switching.

Yeah, you can get a more pronounced different if you add extremes to the equasion. Eg... if you're buying HD6990's you'd probably benefit from the extra bandwidth 16x slots provide.

Assuming you're sticking with the 460's, a 16x8x board (which becomes 8x8x with two cards installed) is the most sensible option bang-4-buck.