Help: Sli & eu

[Mika]

Hey

Coulden't find anything searching for it but

Does SLI work with EU? if no will it when CE2 hits? :P

[Rumsponge]

Afaik, anything works with SLI, it's just a matter of some software being optimized for SLI hardware allowing it to work a little better.

Crysis has an SLI optimization profile, so I assume that Cryengine would, and it would follow that Crytopia will inherit SLI optimizations.

[Compusmurf]

Rum, not exactly true about "anything".

If the software doesn't have a profile, SLI usually falls back to single card by default.

However, you can easily make a profile for EU, I have and it works.

I believe, without checking tho, that I'm set up to use AFR 2 for EU

[Rumsponge]

Interesting. I could be wrong. My understanding was that there were various ways that it can split the work up, and that, in the absence of a specific profile, it defaulted to top half / bottom half. But, I'll do a little more reading.

First Edit:
I guess it would make sense to drop back to single card as there must be a lot of software that doesn't really need a second card.

Second Edit:
Giving it a little more thought, it would be simple for the card to decide on the fly whether in needs to split the work or not. It could then fall back to whatever the default method is.




Sadly, I have an old friend who went to work at Nvidia long ago, but I'm too lazy to go back and dig up his contact info.

[Compusmurf]

absolutely, but if it doesn't have a profile and you didn't FORCE a system wide default (which isn't that great of an idea since some MS products that come with your OS don't like SLi) then it usually defaults back to single.

There isn't much of a benefit for "text" type apps that you use mostly on your computer anyway. Office, web-browsing, etc. Only when you get into full screen graphics rendered apps, but without a profile or a forced profile, Nvidia takes the absolute safest route and uses it's decisions based on each app that has a profile.

Glance in your Nvidia control panel.

You have to have 2 things for SLI to enable. Under the SLI/PHYSX, SLI has to be enabled. (doesn't hurt to enable PHYSX if you have a capable card set either)

Then, under manage 3d settings, you have 2 tabs. Global and Program. You probably shouldn't mess with the Global settings cause this is where you can do the most "harm".

Under the programs, if you select "show programs installed only", it'll show you the apps it has an SLI profile for and how they recommend/force the app.

You can create your OWN for EU.

Now like I mentioned before, based on MY testing, AFR2 works best in EU with physx enabled.

One last caveat. If you are displaying to a LCD screen, the refresh on most of them is set to 60 and it's locked. IF you push frames faster than the LCD can display, you very well could end up with TEARING of the frames which to some folks might annoy them. It doesn't bother me as 99.9999% of EU isn't like playing Battlefield or anything where precise cursor placement and such on your screen is critical.

Your mileage may vary of course, depending on what sets of video cards you have, CPU speed, ram and if you have physx or not, and what type of display you are using.

If you use multiple displays, most of the SLi options disable the 2nd card and you'll lose your 2nd display. That may be an issue for some.

EU as it sits today doesn't get a big boost from SLi so it's not important really. Cryengine, probably. Crysis had a pretty big benefit with SLi mode on my machine.

[Rumsponge]

Excellent response. As a default, I will be willing to accept your version of reality. It seems to be the safest.

[Compusmurf]

Originally Posted by Rumsponge

Second Edit:
Giving it a little more thought, it would be simple for the card to decide on the fly whether in needs to split the work or not. It could then fall back to whatever the default method is.

Yes, unfortunately this is absolutely true and there has been multiple pushes from various standards organizations on how to handle "SLi" mode and whatever other vendors call their multicard setups.

Problem is tho, that Nvidia wants THEIRS to be standard, ATI of course, wants theirs to be the standard, same with every other company that produces multi processor (video) capable cards.

We all know how well that ends up in the real world. 5 different "standards" with no interoperability between them.

THEN the app folks get involved and code their app to work best with whomever they are in bed with this week. (Hence the 'plays best with ATI' or Nvidia logos on game boxes.

[aridash]

Originally Posted by Compusmurf

THEN the app folks get involved and code their app to work best with whomever they are in bed with this week. (Hence the 'plays best with ATI' or Nvidia logos on game boxes.

and remember, Cryengine is in bed with Nvidia, so thats where we want to be