Real World DirectX 10 Performance: It Ain't Pretty
by Derek Wilson on July 5, 2007 9:00 AM EST- Posted in
- GPUs
Introduction
When it was drafted, DirectX 10 promised to once again change the way developers approach real-time 3D graphics programming. Not only would graphics hardware be capable of executing short custom programs (called shaders) on vertices and fragments (pixels), but developers would be able to move much more high-level polygon work to the GPU through geometry shaders. Pulling polygon level manipulation off the CPU opens up a whole host of possibilities to the developer.
With adequate performance, many of the geometric details simulated through other techniques could be applied in simple, straightforward ways involving less overhead. Techniques like normal mapping, parallax occlusion mapping, and many others exist solely for generating the illusion of additional geometry. Ever wonder why a face can be incredibly detailed while the silhouette of the same head looks more like a stop sign than a melon? This is because modern real-time 3D relies on low polygon models augmented with pixel level "tricks" to make up for it.
There are lots of cool thing we can do with the ability to process geometry on the GPU. We could see particle systems on the GPU, fine grained model details like fur that can be affected by the physical characteristics of the world, procedural geometry for highly dynamic environments, "real" displacement mapping, and geometry amplification that can add detail to models. Some of these things may show up sooner than others in games, as we will still be limited by the performance of the hardware when it comes to implementing these features.
There are, of course, other benefits to DX10. We explored this in previous articles for those who are interested, but here's a quick run down. Object and state change overhead has been decreased, allowing for less CPU involvement when sending data to the GPU. This should improve performance and give developers more headroom in building larger, more complex scenes. We have more rigidly defined specifications, which means developers can focus less on how individual hardware will handle their game and more on the features they want to implement. With a larger focus on data types and accuracy, the results of calculations will be more consistent between hardware, and developers will have more flexibility in choosing how their data is processed.
In general, DX10 also offers a more generic computing model with lots of flexibility. This will be very important going forward, but right now developers still have de facto limitations on shader length and complexity based on the performance of the hardware that currently exists. As developers better learn how to use the flexibility they have, and as hardware designers continue to deliver higher performance year after year, we will see DirectX 10 applications slowly start to blossom into what everyone has dreamed they could be.
For now, before we get into features and performance, we would like to temper your expectations. Many of the features currently implemented in DirectX 10 could also be done using DirectX 9. Additionally, those features that are truly DX10 only either don't add much beyond what we would get otherwise, or require quite a bit of processing power to handle. Thus, we either get something that was already possible or something that requires expensive hardware.
When it was drafted, DirectX 10 promised to once again change the way developers approach real-time 3D graphics programming. Not only would graphics hardware be capable of executing short custom programs (called shaders) on vertices and fragments (pixels), but developers would be able to move much more high-level polygon work to the GPU through geometry shaders. Pulling polygon level manipulation off the CPU opens up a whole host of possibilities to the developer.
With adequate performance, many of the geometric details simulated through other techniques could be applied in simple, straightforward ways involving less overhead. Techniques like normal mapping, parallax occlusion mapping, and many others exist solely for generating the illusion of additional geometry. Ever wonder why a face can be incredibly detailed while the silhouette of the same head looks more like a stop sign than a melon? This is because modern real-time 3D relies on low polygon models augmented with pixel level "tricks" to make up for it.
There are lots of cool thing we can do with the ability to process geometry on the GPU. We could see particle systems on the GPU, fine grained model details like fur that can be affected by the physical characteristics of the world, procedural geometry for highly dynamic environments, "real" displacement mapping, and geometry amplification that can add detail to models. Some of these things may show up sooner than others in games, as we will still be limited by the performance of the hardware when it comes to implementing these features.
There are, of course, other benefits to DX10. We explored this in previous articles for those who are interested, but here's a quick run down. Object and state change overhead has been decreased, allowing for less CPU involvement when sending data to the GPU. This should improve performance and give developers more headroom in building larger, more complex scenes. We have more rigidly defined specifications, which means developers can focus less on how individual hardware will handle their game and more on the features they want to implement. With a larger focus on data types and accuracy, the results of calculations will be more consistent between hardware, and developers will have more flexibility in choosing how their data is processed.
In general, DX10 also offers a more generic computing model with lots of flexibility. This will be very important going forward, but right now developers still have de facto limitations on shader length and complexity based on the performance of the hardware that currently exists. As developers better learn how to use the flexibility they have, and as hardware designers continue to deliver higher performance year after year, we will see DirectX 10 applications slowly start to blossom into what everyone has dreamed they could be.
For now, before we get into features and performance, we would like to temper your expectations. Many of the features currently implemented in DirectX 10 could also be done using DirectX 9. Additionally, those features that are truly DX10 only either don't add much beyond what we would get otherwise, or require quite a bit of processing power to handle. Thus, we either get something that was already possible or something that requires expensive hardware.
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titan7 - Wednesday, July 11, 2007 - link
CoH also got 59.9fps on the GTX Ultra. Today's d3d10 games can run at full frame rates on today's hardware. Just ensure you're using the latest drivers and you have the most expensive card money can buy ;)BigDDesign - Thursday, July 5, 2007 - link
I'm with Derek here. I liked your article. We need much more powerful hardware and time for DX10, Drivers, Developers & Vista to get it together. A couple of years from now, all should be good with DX10. Not any sooner methinks.WaltC - Thursday, July 5, 2007 - link
This article, I thought, was extremely poor for several reasons:(1) DX10 in terms of developer support presently is just about exactly where DX9 was when Microsoft first released it. At the time, people were swearing up & down that DX8.1 was "great" and wondering what all of the fuss about DX9 really meant. Then we saw the protracted "shader model wars" in which nVidia kept defending pre-SM2.0 modes while ATi's 9700 Pro pushed nVidia all the way back to the drawing boards, as its SM2.0 support, specific to DX9, created both image quality and performance that it took nVidia a couple of years to catch.
AnandTech did indeed mention almost in passing that DX10 was still early yet, and that much would undoubtedly improve dramatically in the coming months, but I think that unfortunately AT created the impression that DX10 and DX9 were exactly *alike* except for the fact that DX10 framerates were about half as fast on average as DX9 framerates. A cardinal sin of omission, no doubt about it, because...
(2) DX10 is primarily if not exclusively about improvements in Image Quality. It is *not* about maintaining DX9-levels of IQ while outperforming DX9. It is about creating DX10 levels of Image Quality--period. AnandTech does not seem to understand this at all.
(3)First lesson in Image Quality analysis that even newbies can readily understand is this: if the performance is not where you want it, but the IQ is where you want it, then you do the following to improve performance *without* sacrificing Image Quality (This is a lesson that AnandTech truly seems to have completely forgotten):
Instead of talking about how sorry the performance was in DX10 titles (those very few early attempts that AT looked at), AT should have seen what AT could have done to increase performance while maintaining DX10-levels of Image Quality. That is, AT should have *lowered* test resolutions and raised the level of FSAA employed to get the best balance of Image quality and performance. AnandTech did not even try to do this--which in my view is inexcusable and fairly unforgivable. It is a very bad mistake. I'm sorry--but many, many people, including me, do not use 1280x1024 *exclusively* while playing 3d games. My DX9 resolution of choice is 1152x864, for instance.
The point to be made about DX10 is *not* frame rates locked in at 1280x1024. Sorry AT--you really screwed the pooch on this one. The whole point of DX10 is *better image quality* which everyone who ever graduated from the 3d-school-of-hard-knocks is *supposed* to know!
So, just what does a bunch of *bar charts* detailing absolutely nothing except frame rates tell us about DX10? Not much, if anything at all. Gee, it does tell us that with the reduced image quality that DX9 is capable of providing contrasted with DX10, that DX9 runs faster in terms of frames per second on DX10 hardware! Gosh, who might ever have guessed....<sarcasm>
IMO, the fact that DX10 software even early on is running slower than DX9 on DX10-compliant hardware tells *me* nothing except that DX10 is demanding a lot more work out of the hardware than DX9, which means that we can expect the Image Quality of DX10 to be much better than DX9. These early games that AT tested with are merely the tip of the iceburg of what is to come. AnandTech really blew this one.
Jeff7181 - Tuesday, September 11, 2007 - link
"DX10 is *not* frame rates locked in at 1280x1024"Too bad you didn't say this earlier in your rant, I could have saved myself a few minutes and stopped reading sooner.
Thanks for the laugh though... imagine... someone who thinks 1280x1024 is a frame rate telling AnandTech they screwed the pooch when publishing this article. LOL
titan7 - Thursday, July 12, 2007 - link
This article was awesome. Too bad reality doesn't match your expectations or you'd like it too.1) You have no idea what the "shader war" was about. There isn't even a single parallel to be drawn if you *correctly* look back.
2) d3d10 is nothing about image quality. No hardware on the market or rumoured to be coming out next generation can handle running a full length SM2.0b shaders! And forget about even 3.0! Or even 2.0a that the GeForceFX supported for that matter. d3d10 is about one thing-making d3d on the PC more like a console. That means lower CPU (not GPU!) overhead (more performance in CPU limited situations) and making lives easier for developers.
3) AT has CoH at 1024x768, 1280x1024, 1600x1200, and 1920x1200 (common native LCD resolutions). These days everybody has bigger monitors and playing below 1024x768 is pretty rare. You can extrapolate your 1152x864 resolution from that.
What this shows us is if you increase the image quality (see the screen shots) today's cards don't have enough power to run at full frame rate, with the exception of the 8800 GTX Ultra. AT did a great job showing the world that with simple bar graphs and everything. It's too bad you were too angry to realize that is all it was trying to show.
strikeback03 - Friday, July 6, 2007 - link
umm, they tested Company of Heroes and Call of Juarez at 1024x768, and Lost Planet at 800x600, and some of the cheaper cards could still not maintain playable frame rates. How low on the resolution do you want them to go?jay401 - Friday, July 6, 2007 - link
I'm not sure how raising FSAA is going to improve performance?Nor how removing DX10 visuals but lowering screen res will "maintain DX10 level of visuals" either?
anandtech02148 - Thursday, July 5, 2007 - link
Excellent sincere analysis of the current hardwares situation. Which lead me to some after thoughts,- Maybe a 600buxs PS3 isn't so bad after all.
-What am i going to do with this 8800gtx and the lack of pc games, quite dry season compare to consoles.
-For those of you who hold out longer than I have, a 8800gts or 2900xt is a decent investment if you have a 1920x1200 monitor to go with it.
kilkennycat - Thursday, July 5, 2007 - link
... if you presently have a DX9 system with acceptable performance. Until the NEXT generation of DX10 hardware is released.Anybody who goes out and buys a current Dx10 card ( or even worse, dual cards ) just because "the Dx10 games are coming" ( and "I want bragging-rights") has a lot more money than sense. Buying a 8600 or 2600 for acceptable HD-decoding in your HTPC (or your mid-range PC with a weak CPU) is the only purchasing action with the current Dx10 offerings that makes total sense. All of the upcoming Dx10-capable game-titles for 2007 will have excellent Dx9/SM3 graphics. The lack of Dx10 hardware will smother "bragging-rights" but will have zero effect on playability.
nVidia has been developing the successor family to the G80-series GPU for almost a year now and the first graphics cards from this new generation are expected by the end of 2007. I would not be at all surprised if the first card out of the chute in the new family will immediately fill the cost-space between 8600GTX and 8800GTS, but with DX9 and Dx10 performance far superior to the 8800GTS. No doubt the GPU will also be 65nm, since the manufacturing/yield cost of the huge 80nm G80 die is the immovable stumbling-block to dropping the price of the 8800GTS.
KeithTalent - Thursday, July 5, 2007 - link
That's fine if you game at resolutions below 1680x1050, but some of us game at higher resolutions, and most high-end DX9 cards were struggling mightily to play the latest DX9 games (Oblivion, Supreme Commander, STALKER, etc...).These new generation cards are not only about DX10, they are also about improved performance (exponentially improved performance actually) over that last generation, and some of us actually need that power.
What you said is all well and good for you if you are still gaming at 800x600 or whatever, but I like my resolution a little higher thank you very much.
KT