Mousemonkey :
I want proof from somewhere other than your site as my experience with SLi'd 560Ti's doesn't seem to match yours but it does match other sites that are considered reputable.
Hard to answer that when I don't know what your experiences are.
What are your tests results? What is it you're seeing that's bugging you
with your cards? Indeed, which model cards do you have? If your cards are
the lesser ones with clocks around the 830 range then yeah perhaps not so
impressive - that's why I bought two 900MHz EVGA Crysis Editions. 8)
Since they're the main cards in my current gaming PC though, I haven't
yet tested them much except for various 3DMark runs (06, Vantage, 11,
Firestrike, etc.) In theory I could replace them with two reference 580s
I recently obtained (though that's overkill for the games I'm playing
just now), but it'd be a bit of a squeeze in the case (Antec 300) and I
don't know if the PSU could cope (850W... maybe, would need to check).
To summarise: I need a lot more info to be able to help with your
specific query.
Btw I'm not talking here about overall 3DMark scores which can of course
be skewed by CPU performance because of the Physics/Combined tests; I mean
check the Graphics scores individually. For example, here's a typical 670
vs. my 560Tis SLI at stock speed (the person who owns this 670 is someone
from whom I bought one of my 460s, so he supplied me with some test info):
http://www.3dmark.com/compare/3dm11/5859252/3dm11/6035982
Check the graphics scores: almost identical. And with the 560Tis oc'd:
http://www.3dmark.com/compare/3dm11/5859252/3dm11/6037434
Now the 560Ti SLI Graphics score has shot up. This is just an example though.
As always, it varies depending on the task, eg. my 560Tis would likely be
hopeless for running Firestrike Extreme because that test needs more than
1GB VRAM. What game are you running? Or is it some other task? Happy to
help if I can.
Ian.
PS. One thing though, don't use the 320.18 driver, it's not so good for
cards like the 460/560.