rapid1 wrote:I am at a kind of indecision right now. with the 560 and 6870
I just got a XFX HD6870 and it's a nice card, you get game play that's smooth as can be. I don't have anything bad to say about it at all, except for the lack of CUDA and PhysX support. (but I knew this when I bought the card) I bought it a week before the GTX560 was introduced (not knowing that the 560 was on the way) and I have to say that I would have bought the GTX560 card if it would have been out at the time, just because of those two features. It makes a difference in some games and when it's enabled and active, it's cool.
Rofl; you can run PhysX on an ATI card I have it on my PC as it was required for Dragonage when I played it, now I don't know about CUDA, but I know ATI has there own program like it, so if I can install and use PhysX I would imagine CUDA goes with that.
I think you may be mistaken, rapid1.
You might be able to "Install" the PhysX drivers, but it will only run on your CPU. PhysX hardware acceleration and CUDA are written to be proprietary to the nVidia card back end. PhysX hardware acceleration even gets disabled on nVidia cards if you also have an ATI card installed, since driver 186 or so.
All I know is you have to have PhysX to run DAO, and if it is disabled it will give you a load error when the program is activated from your desktop. So I had to install it, and it ran just fine after I did. It has been a while since then. I just know I had to install it, and it had to be active against the CPU as well as the GPU for the game to fully load.
3vi1 wrote:PhysX hardware acceleration and CUDA are written to be proprietary to the nVidia card back end
After rapid1's comment, I looked around online, and I found that there are a few hacks in the wild that allow for PhysX to run with an ATI/AMD card in your system.
But that is with the caveat that you have to have an NVIDIA Card installed too, and it has to be the one that does the PhysX processing. I was going to try it out to see if it was worth it to do, but twice, when I downloaded the hacks, my anti-virus alerted on them.
At that point it wasn't just wasn't worth any further investigation as far as I can see, and I still stand by my earlier comment about what card to buy for PhysX. (if you want to do it without jumping through hoops and ringing someone's bells)
I've seen lots of people slam PhysX as being insignificant or not so compelling, but most of them are running an ATI/AMD card. Where I have enabled it with one of my better NVIDIA cards, I've found it to be relevant, and a welcome addition to my gaming.
Overall, I only have to please myself, (Ricky Nelson said that in a song) and I'm pleased with PhysX.
EDIT: I want to add that I did install PhysX onto one of these systems with a PhysX capable card (GTX-285 2GB) in it at the time. I got it working perfectly, and then substituted the NVIDIA card with a Radeon HD-6870 That I had on the shelf. I had previously had the Radeon card in there, and had left it's driver alone, so I had all of the drivers for both cards setup at the same time. I was able to turn on the PhysX in my games, but it worked out a lot like like trying to put socks on a Rooster. [*-)] PITA [*-)]
All I know is you have to have PhysX to run DAO
I believe you. The thing is, if you install PhysX without an nVidia GPU, it falls back to CPU-only mode (which performs relatively poorly compared to the hardware accelerated version). The CPU train of code is not at all optimized, probably purposely, so as to make the nVidia hardware 'more valuable' for games that use PhysX.
Yes. GPU's are like CPUs: Each manufacturer has their own set of opcodes. Running the nVidia PhysX code on an AMD/ATI card would be like trying to run x86 software on a PowerPC CPU... They literally speak a different language.
The only way to run PhysX or CUDA code on an ATI card would be to write an emulator that converts all the operations to those of the host card. it would be incredibly hard to do (because of the widely varying capabilities of all the GPUs), and add a significant overhead.
This proprietary implementation is what makes the alternatives like OpenCL so attractive. As an intermediate interface that's supported by both manufacturers, you don't have to write your code twice.
No actually when I ran it it was ran with my CPU. My I7 did not have any issues with it. Of course with 8 available threads that kind of stands to reason. So I ran PhysX against the OC'd I7 rather than the GPU (5870 or 5870/5850) and ran everything to highest detail without a hitch. From what I understand if you have an Nvidia car it actually runs combined between the GPU and CPU anyway. As I said though I had absolutely no issues, and everything worked fine on highest detail.
I apologize about the responses before, but I did not really think about it to tell you the truth. The graphics were coming through my GPU so I did not really think about it. Everything ran fine though on full detail which led me to believe at the time that Physx was and is pretty much a rip off as a singular application thread, and or reason therefore to buy an Nvidia card for it. Because it ran in combination between my GPU and CPU without issue or flaw, and my GPU is an ATI. So if a current processor has more than enough power ( I also ran it on Sarah's 965 black equipped system with no issues), and everything looks great on highest graphics detail why would I or should I spend the extra money to get it?
Some games look a lot better with PhysX installed and running on the GPU. I don't know if it goes to how they're coded, or if they have a heavier implementation of PhysX within the game. How it works doesn't interest me as long as it works.
I do know that if I go to my NVIDIA drivers settings and choose to render PhysX with the CPU, (i7-870 running @ 3.93GHz. speed and 8GB of DDR3-1600 RAM) It looks like crap and is jerky as can be. But if I go back to my drivers settings and choose to render PhysX with the GPU, It works perfectly and at high detail. I have a GTX-285 2GB, a GTX-570 1,280MB, and a GeForce GT-430 1GB that all do PhysX and CUDA nicely.
It happens exactly the same with my other i7-870 system. (running @3.8GHz. speed and 8GB of DDR3-1600 RAM)
It happens the same with my i5-750 @ 3.8GHz. system with the same RAM in it too.
My Radeon HD-5850 and my Radeon HD-6870 don't do it at all. The effects just aren't there.
No need! We're all here to share, and we all learn from each other. You're cool in my book.
To tell you the truth, I think PhysX is overrated. I think that's why their original model, where they had a separate PhysX card failed. So, I agree with you: The hardware acceleration just doesn't make that much of a difference in most games - unless the rest of your system is anemic.
PhysX is a bit over rated like 3vi1 says. Some games use it well, others dont. I say if you have a Nvidia crad enjoy it. If you run an ATI card dont worry about it.