HEXUS.help :: Windows Vista: DirectX10 D3D Intro

[Steve]

After being tasked with writing this DirectX 10 piece, I was asked, "what does DirectX 10 mean to me as a PC consumer, right now? Explain that in the piece, I think that's what people want to know". The questioner asks brilliantly.

http://www.hexus.net/content/item.php?item=6161

[Silent Shark]

I think that some DX9 - DX10 images would be appropriate:




I'm really looking forward to DX10. The jump in game graphics quality will be immense, and it's a big selling point of Vista for me. It's also great news that coding will be simpler, as it will allow developers to spend more time finishing their games and not debugging the graphics. I only hope that the DX10 graphics cards are reasonably priced when they arrive!

EDIT:
Another image, in case mart_haj86 is right about the image being mocked

[mart_haj86]

Looks great Silent_Shark however I think I read somewhere that the DX10 picture was an artist impression of what it could be like. But Im all for it if the water will definately look that real.

[toolsong]

As a PC gamer, I can't help but feel that the only reason I will be really interested in Vista is to play a DX10 optimised/exclusive game on a DX10 GPU.

Hype aside, what will it give Joe Bloggs in the short term that warrants the upgrade price and likely need for new hardware over XP?

Security improvements will need to be proven and the media/HTPC market isn't that big.

[Stoo]

Not a whole lot tbh, but then again most people switched over from 2000 to XP for the better games support..

[kalniel]

Looks great Silent_Shark however I think I read somewhere that the DX10 picture was an artist impression of what it could be like. But Im all for it if the water will definately look that real.

Yup, it's just an artists impression.

The far cry image is running on dx9 cards as well

D3D9 performance will be slightly up on Vista because of the new driver model and runtime architecture.

I had heard this as well, but care to explain why exactly?

Finally, at what point does the list of instructions to the graphics card become a problem? We are adding more and more possible stages that can be done on the hardware without a call back to the CPU, but presumably that increases the instruction queue. Will that ever become detrimental?

[ExceededGoku]

he did explain it, there is less overhead and the driver has system level access.... It becomes good at high resolutions and anti aliasing (which are relatively intensive)

[dangel]

he did explain it, there is less overhead and the driver has system level access.... It becomes good at high resolutions and anti aliasing (which are relatively intensive)

A _lot_ less overhead - something like upto 40% and there's no penalty for context switches like there is on XP (think: time it takes to switch from a game to the desktop, or the penalty incurred for running a game in a window).

[Rys]

I had heard this as well, but care to explain why exactly?

Finally, at what point does the list of instructions to the graphics card become a problem? We are adding more and more possible stages that can be done on the hardware without a call back to the CPU, but presumably that increases the instruction queue. Will that ever become detrimental?

The driver and runtime are less involved in setting render state, and draw calls spend much less time on the CPU before the GPU starts doing its work. So the knock on effect, considering a few more things, is that apps can possibly get automagically quicker on the same hardware with the new runtimes on Vista.

Basically it's architecture of the runtime based on the new driver model that's allowed Set/Draw function overhead to be much reduced.

As for instruction counts, there'll always come a point where over a certain number of instructions that performance will start to fall off, but that's largely down to execution time, not the count itself. Chips only have caches big enough for a few dozen instructions at a time at best anyway, with the driver constantly feeding it new work to do, and nowadays you effectively have unlimited instruction slots with which to do work, as far as the runtime is concerned.

So now it's mostly a matter of how long your shaders take to execute, and with D3D10 finding the balance between three major render stages, not just two.

[Rys]

he did explain it, there is less overhead and the driver has system level access.... It becomes good at high resolutions and anti aliasing (which are relatively intensive)

Perf can also increase at lower resolutions when CPU limited, if part of your CPU limitation was runtime overhead. And AA isn't something affected by the overhead. Infact the overhead can sometimes mean you start to get your AA effectively for free, if you spend sufficient time on the CPU rather than the GPU, and turning it on comes at little extra cost to framerate.

[Silent Shark]

I'm currently trying out the new RC1 version of Vista, which is running DX10, according to dxdiag.

Will I get the improved DX9 performance with a DX9 card, or will it only improve with a DX10 card?

I haven't got the HDD space to try out any games in Vista atm, but a new HDD should be arriving from Scan tomorrow, so hopefully when I try some games, Vista isn't lying and I do have DX10. If I notice any difference in performance, I'll let you know.

If someone else is running RC1, and has tried games, have you noticed anything?