Let's Talk about PhysX Baby

When AMD and NVIDIA both started talking about GPU accelerated physics the holy grail was the following scenario:

You upgrade your graphics card but now instead of throwing your old one away, you simply use it for GPU accelerated physics. Back then NVIDIA didn't own AGEIA and this was the way of competing with AGEIA's PPU, why buy another card when you can simply upgrade your GPU and use your old one for pretty physics effects?

It was a great promise but something that was never enabled in a useable way by either company until today. Previous NVIDIA drivers with PhysX support required that you hook a monitor up to the card that was to accelerate PhysX and extend the windows desktop onto that monitor. With NVIDIA's 180.48 drivers you can now easily choose which NVIDIA graphics card you'd like to use for PhysX. Disabling PhysX, enabling it on same GPU as the display, or enabling it on a different GPU are now as easy as picking the right radio button option and selecting the card from a drop down menu.

When we tested this, it worked. Which was nice. While it's not a fundamental change in what can be done, the driver has been refined to the point where it should have been in the first place. It is good to have an easy interface to enable and adjust the way PhysX runs on the system and to be able to pick whether PhysX runs on the display hardware (be it a single card or an SLI setup) or on a secondary card. But this really should have already been done.

There is another interesting side effect. When we enabled PhysX on our secondary card, we noticed that the desktop had been extended onto a non-existent monitor.

Windows has a limitation of not allowing GPUs to be used unless they are enabled as display devices, which was the cause of the cumbersome issues with enabling PhysX on a secondary card in the first place. Microsoft hasn't fixed anything from their end, but NVIDIA has made all the mucking around with windows transparent. It seems they simply tell windows a display is connected when it is actually not. It's a cool trick, but hopefully future versions of Windows will not require such things.

Mirror's Edge: The First Title to Impress us with GPU PhysX?

Around every single GPU release, whether from AMD or NVIDIA, we get a call from NVIDIA telling us to remember that only on NVIDIA hardware can you get PhysX acceleration (not physics, but PhysX). We've always responded by saying that none of the effects enabled by PhysX in the games that support it are compelling enough for us to recommend an underperforming NVIDIA GPU over a more competitive AMD one. Well, NVIDIA promises that Mirror's Edge, upon its release in January for the PC will satisfy our needs.

We don't have the game nor do we have a demo for anything other than consoles, but NVIDIA promises it'll be good and has given us a video that we can share. To under line the differences between the PhysX and non-PhysX version, here's what to look for: glass fragments are a particle system without PhysX and persistent objects with (meaning they stick around and can be interacted with). Glass fragments are also smaller and more abundant with PhysX. Cloth is non-interactive and can't be ripped torn or shot through without PhysX (it will either not there at all or it won't respond to interaction). Some of the things not shown really clearly are that smoke responds to and interacts with characters and leaves and trash will blow around to help portray wind and in response to helicopters.

Another aspect to consider is the fact that PhysX effects can be run without GPU acceleration at greatly reduced performance. This means that AMD users will be able to see what their missing. Or maybe an overclocked 8 core (16 thread) Nehalem will do the trick? Who knows... we really can't wait to get our hands on this one to find out.

We'll let you be the judge, is this enough to buy a NVIDIA GPU over an AMD one? What if the AMD one was a little cheaper or a little faster, would it still be enough?

We really want to see what the same sequence would have looked like with PhysX disabled. Unfortunately, we don't have a side by side video. But that could also significantly impact our recommendation. We are very interested in what Mirror's Edge has to offer, but it looks like getting the full picture means waiting for the game to hit the streets.

Multi-monitor SLI Users Rejoice! Driver Performance Improvements


View All Comments

  • Intelman07 - Monday, November 24, 2008 - link

    I most certainly do not regret switching from Nvidia to ATI. Nvidia's drivers were horrid in Vista. I've not had too many issues since. I do not mind bashing ATI as much as I mind praising Nvidia.

  • kondor999 - Tuesday, November 25, 2008 - link

    I'm running 3 GTX280's in Tri-SLI under Vista x64 and the 180.xx have made a large difference by greatly increasing the *minimum* framerate in games such as Far Cry 2 and Warhead.

    Of course, be advised that I'm running these at 5040x1050 using a Matrox TH2Go at 4-8x AA.
  • Mr Roboto - Wednesday, November 26, 2008 - link

    Good for you, you poser. I know you're type. The kid at school who thought that by lying about his personal possessions he was somehow cool or that he would gain more friends. It turns out those types are just compulsive liars with NO friends. We called them lietokickits. You don't have to lie to kick it. Especially in the Anand Tech comments section. Reply
  • SiliconDoc - Friday, December 26, 2008 - link

    It really doesn't look like you called that one correctly:
    Note the date, Oct. 30th 2007 kondor999 " got a copy of Vista Ultimate OEM on the day it was released, quickly discovered that performance was poor (specifically - graphics, audio, and file copying) and shelved it after struggling with it for 3 months. I'm now back to my old copy of XP Pro and it's just so much nicer. Simply put, everything works as it should. BTW, I have a nice rig: 3ghz Core2, 2gb RAM, 8800GTX, dual 150gb Raptors. If my rig chokes on Vista..."
    Then there's the age match > " http://www.ageod.com/forums/member.php?u=4951">http://www.ageod.com/forums/member.php?u=4951
    Join Date
    June 18th, 2008
    Total Posts
    " I'm an older gamer (42) and I remember when games like Longbow 2 and F-15 came with big ring-bound manuals that ensured you *wanted* to buy the physical game " (from the first link)
    Then there's this:
    Looks like the money is there.

    Oh well, better luck next time.
  • george1976 - Monday, November 24, 2008 - link

    Well, talking about stability, i have problems now with NFS Undercover with this new driver, problems i never had with 178.24.... So much for treats... Reply
  • fausto412 - Monday, November 24, 2008 - link

    Every driver after 178.13 breaks AA in Battlefield 2142. I just downloaded 180.48 drivers and they make left 4 dead stutter so much it is unplayable. I try new drivers and go back to 178.13 everytime. what gives Nvidia? Anyways, perhaps Anandtech can question Nvidia on the stability of their drivers. Reply
  • rocky1234 - Sunday, November 23, 2008 - link

    Wow big deal Nvidia releases a driver & everyone goes crazy yay. They add a few small features & make a big stink about it yippy. Have they fixed the Vista issues yet don't know because I gave up waiting 6 months ago & switched to the red team. PhysX is a nice feature but even a Owner of a ATT card & windows XP can go out & buy a cheap Nvidia card slave it & install these magic drivers & get PhysX in the supported games that is if you got a second PCI-E x16 slot. At least that is what I heard people are doing I own a 9800GTX it is sitting on the floor here I may try it to see it it works...lol. Now if MS would come out with a patch for Vista that would allow you to do it there too that would rock. Reply
  • Mr Roboto - Saturday, November 22, 2008 - link

    Am I the only one who seems to see through Nvidia'a bullshit? Why is Anand praising them for un-crppling their drivers after five YEARS! When the only reason they're doing it is because AMD is handing them their ass!

    Nvidia is in a free fall so they finally start to pull out all the stops and release features that they should have given their users years ago. I mean it only took ATI to essentially kill their profit margins on the GTX series for them to release dual monitor SLI.

    I'm a long time Nvidia owner (8800GTX) but even I see the way Anand lays on the bullshit real thick. Quit playing nice for Nvidia. Are you afraid they won't send you review hardware or return your phone calls?

    Well since Anand won't do it I guess the readers must.

    Nvidia's Vista drivers were nothing short of fucking atrocious for YEARS (there's that word again). Only in the last 3-4 months have they gotten a little better, coincidence? (4800 launch). Nvidia even had SLI working on the Quadro setups for YEARS. Now that they're falling fast they decide to un-cripple their desktop drivers. This goes hand in hand with gouging their customers, pushing flaky hardware out into market (G92-94), IMAP bullshit, the fucked up, confuse the noobs naming scheme and broken, buggy and just all around shitty drivers.

    Fuck Nvidia and fuck their shit motherboards. I was a loyal Nvidia owner for as long as I can remember but they have taken greed and screwing their customers to another level. I hope

  • Mr Roboto - Saturday, November 22, 2008 - link

    I hope ATI takes them to the brink of bankruptcy but only for the sake of competition. Otherwise I could care less about Nvidia and their busted hardware. Reply
  • JonnyDough - Friday, November 21, 2008 - link

    Is a simple email informing me of new driver release with a link to the page and what it fixes/changes. A VERY simple email. I don't care WHEN they release the driver, but more importantly that it works and that I know it's available for download. Too many releases just gets to be a hassle, not enough means I have to wait forever for my favorite application or game to work properly. Communication between graphic card companies and software companies probably could use some improvement as well. The way I see it, AMD/NVidia/Intel need to get on board with a standardized support of their products using the email method. Software developers should have a single website to access all three in regards to drivers, and end users should have a standardized email platform from all three. When companies get together and provide good support for their products, everyone wins. As long as they don't lie in bed together on making money, hardware and software can advance at a faster and more complete pace than they have previously...and that means smoother computing for all. Reply

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