NVidia's SLI scaling, is the hardware the advantage?

[AMW1011]

Hey guys, I've been reading a lot about the 80-90% SLI scaling with the new GTX 4xx series. I tested my current 8800 GTS 512mbs in SLI and got about a good 60-70% scaling across the board with an i5 750 at 4.0 GHz, so no bottleneck there. So, is the insanely good SLI scaling part of the Fermi architecture? Are my results off? I don't remember the GTX 2xx series being that good with scaling. Does anyone have any insight to this? I haven't been able to find anything concrete, but the Fermi coverage was plentiful so rummaging through it is difficult. If you have the time it would be great if anyone with an SLI setup posted some results up for comparison.

The new GTX 460s are tempting me. My 512mb of VRAM really holds me back and I know a GTX 460 will perform as well or better than my current setup, and that is without even considering overclocking as my new secondary 8800 GTS 512mb doesn't overclock at all, and I mean at all. So the idea of 2 GTX 460s, even if I can only get the 768mb versions, seems like a great upgrade for me as I should get over twice the performance with SLI scaling, assuming its the same as my current setup which it doesn't seem to be, and the extreme overclocking potential. I think twice the performance, or more, is a good upgrade.

Thoughts? Opinions? Speculation? Conspiracies? Anything would be appreciated as this is bugging me.

 

[Lmeow]

I'm pretty sure Fermi scales better in SLI because of its architecture more than its drivers. I want a GTX 460 too... but I'll need to save up. The 768 MB would be decent enough if you play at 1920 x 1200 or less.

 

[AMW1011]

That is what I am thinking, but I am trying to find some hard evidence.

 

[4745454b]

And your CPU is?

 

[Lmeow]

AMW has a Core i5 750 4.0 GHz 1.4V cooled by a Xigmatek HDT-S1283.

My CPU is a Core i7 930 2.93 GHz 1.2V cooled by a Prolimatech Megahalems.

 

[baddad]

When I started with 2 8800gtx's my scaling was just over 90% then I added a 3rd card it dropped to 40% on that card. I think for two cards the scaling is great with the 400's but for a 3rd card I'm not sure.

 

[dimmyk]

That is what I am thinking, but I am trying to find some hard evidence.

Here is how my EVGA GTX 460 768MB scale in SLI @ 1680x1050 (left - single card, right - both cards):

Crysis Warhead

Unigine Heaven

AVP Benchmark

Needless to say, I just love them

Rest of the system:

I7-930 @ 3.78
ASUS P6T Deluxe V2
6GB Mushkin Blackline DDR3 RAM
Silverstone 850W 80+ Silver PSU