9800 GT helps out 480 SLI tremendously in PhysX

http://forums.evga.com...p;m=321112&mpage=1

So in the above thread, I had previously concluded that the 9800GT gives a huge boost to a single 480 GTX but only a very small boost to 2 480 GTX in SLI. 

It turns out that was a wrong conclusion.  The previous results were based on running the test at 4xAA in 1920x1200.  I got very different results once I turned the AA up to 32xAA.  As you can see, a 9800 GT offers tremendous benefits when the two 480 GTX are working at full load.   Even when the 480s are greatly overclocked, they fail to come close to matching a 9800GT + 2 stock 480.   It's just not so apparent when the 480s aren't working so hard on graphics. 


480 SLI stock




480 SLI overclocked 800/1600/2000




480 SLI stock plust 9800 GT

I never tried that demo, but that is a huge increase.

The performance benefit is huge enough that I'm gonna keep the 9800 GT in that config.  Aside from the increased power draw, the main issue with having a 9800 GT is increasing temps significantly on the adjacent 480 GTX. 

In my config, the 9800 GT is sandwiched between the two 480s.  There's not much impact on the bottom card as it still gets good airflow.  However, the top card, which was already hotter to begin with, goes up by at least 10C. 

I really wish I don't need the 9800 GT.  The two 480s run so much cooler with nothing in between.  By placing a slot cooler in between, I was even able to keep temps at no higher than 90c while overclocking to 800/1600/2000. 

did you try that patch for the 480's and batman yet. 
http://download.cnet.com/Batman-Arkham-Asylum-GTX-470-and-480-Rigid-Bodies-PhysX-patch/3000-7492_4-75179434.html
it is supposed to increase the physx in the game.  i have it downloaded but i am waiting for my cards to arrive today.  i will test 2 480's and a 285 for physx and see if there is a difference

I'll have to give that a go

You know whats strange is I get better fps using my 260 running the physx,than I do using my 250 as a dedicated physx card in batman.

chump7431

did you try that patch for the 480's and batman yet. 
http://download.cnet.com/Batman-Arkham-Asylum-GTX-470-and-480-Rigid-Bodies-PhysX-patch/3000-7492_4-75179434.html
it is supposed to increase the physx in the game.  i have it downloaded but i am waiting for my cards to arrive today.  i will test 2 480's and a 285 for physx and see if there is a difference

Yeah, I did.  The 480s actually perform quite well by themselves, as long as they aren't working too hard on rendering graphics.  Check out my last thread.  With just 4Xaa, the two 480s are almost equivalent with two 480s + 9800.

rhcliff,

Even though we have very similar setups, we are getting very different results. Something I don't understand is how you are able to change AA to 32x. I went into the Batman settings menu, and AA was disabled by default, and the max I have the option of setting it to is 16XQ. There is no 32x option for me.

You tested your 480's with both stock clocks, and overclocked. I tested my two 480 SC's at stock "SC" clocks, which is just above your stock clocks, and well below your overclocked settings, and here's what I get with AA being disabled in the Batman settings menu:

Min - 51
Max - 199
Average - 116

When I add a 9800GT to the mix, I actually get a *lower* score:

Min - 53
Max - 151
Average - 110


I'm going to test again by enabling AA to the highest it will let me set it to, which is 16XQ.

jdookie

rhcliff,

Even though we have very similar setups, we are getting very different results. Something I don't understand is how you are able to change AA to 32x. I went into the Batman settings menu, and AA was disabled by default, and the max I have the option of setting it to is 16XQ. There is no 32x option for me.

We're not getting different results.  Like I said, you have to push the two 480s enough before you can see the 9800 GT's impact.  Up to 4xAA, the 9800 GT doesn't make much of a difference.  If you're not even using AA, it's unsurprising that the 9800 GT actually brings down performance.

I use 32X through the Nvidia control panel.  Either override or enhance will work.  I also set everything else at "High quality" in the panel although it shouldn't make much difference. 

You're absolutely right. With AA turned up, the 9800GT definitely *does* add performance. What I don't understand is why it doesn't become apparent until a load is placed on the 480's.

Here's my results with 16XQ AA, set in the Batman settings menu:

Dual 480 SC's only (stock clocks)

Min - 36
Max - 107
Avg - 70

Dual 480 SC's + 9800GT for PhysX (all stock clocks)

Min - 55
Max - 145
Avg - 100

One more test with settings changed in the NVidia Control Panel from "Application Controlled AA" to "Enhance the application setting" and then setting AA to "SLI 32x". Batman settings menu AA setting is still 16XQ.

Dual 480 SC's + 9800GT

Min - 38
Max - 120
Avg - 77


I guess I'll be keeping my 9800GT after all. Thanks for the info!

You're welcome.  The 9800 GT doesn't help out until higher AA settings because the 480s are already quite powerful.  At up to 4XAA, there's still enough reserve power to do PhysX without having a major impact on performance.  That's why a 9800 GT won't help in those scenarios where the 480s are not fully worked. 

It's not just AA either that would make a PhysX card come in handy.  Metro at max settings, 1080P pretty much stresses out two 480s already so PhysX would once again have a huge impact on performance if there isn't a dedicated PhysX card. 

Cool bro, thanks for posting this. I actually had my 9800GT on eBay, and then canceled the listing after finding this out today.

rhcliff13

http://forums.evga.com...p;m=321112&mpage=1

So in the above thread, I had previously concluded that the 9800GT gives a huge boost to a single 480 GTX but only a very small boost to 2 480 GTX in SLI. 

It turns out that was a wrong conclusion.  The previous results were based on running the test at 4xAA in 1920x1200.  I got very different results once I turned the AA up to 32xAA.  As you can see, a 9800 GT offers tremendous benefits when the two 480 GTX are working at full load.   Even when the 480s are greatly overclocked, they fail to come close to matching a 9800GT + 2 stock 480.   It's just not so apparent when the 480s aren't working so hard on graphics. 


480 SLI stock




480 SLI overclocked 800/1600/2000




480 SLI stock plust 9800 GT

Are you on air or water?

Interesting.  Nice post.  I am sure this will help a lot of people make the jump to a dedicated physics GPU.  I don't have the room for one right now though

Damn that is a huge jump in FPS, and all this time I thought a dedicated PhysX card wasn't needed in SLI configs.

although 32fps min is still a playable without it.

devilstestament

Are you on air or water?

Air.  One of the detriments of keeping a 9800 GT in my rig is that the 480 directly above it gets much hotter.  But as you can see, even two heavily overclocked 480s can't beat a pair of 480s with the help of a 9800 GT. 

_Nite_

Damn that is a huge jump in FPS, and all this time I thought a dedicated PhysX card wasn't needed in SLI configs.

although 32fps min is still a playable without it.

Yeah, I wouldn't say that a dedicated PhysX card is essential for two 480 GTXes.  But if you bought 2 480s, then you're probably a framerate freak and a $100 dedicated PhysX card is one of the best investments that can be made. 

The nice part about it is alot of us don't have to go and buy another video card and we have one just laying around