Question PCI (Non Express) GPU Options

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Insert_Nickname

Diamond Member
May 6, 2012
3,587
128
126
#27
GMA 950 (and I think other derivatives, like GMA 3100) is really horrible on Windows 10 (on 7 it's just very bad, but doesn't have this problem to this extent, and you can eliminate the dwm.exe hit by disabling Aero), even with drivers installed you can get almost 1 core fully loaded with just dwm.exe if you are watching a video on the web browser, because of how much work is being done by the CPU
In 7 you can get away with using a XPDM driver, since there is still a GDI+ fallback to the DWM compositor. This is what happens when you disable Aero. Vista has the same, but actually keep a complete copy of both compositors. Which is why 7 runs better in some cases, and is one of the reasons for Vistas higher memory requirement.

This was removed with 8 (pure Direct3D DWM compositor) and later, which is why you almost -need- a WDDM 1.1 compliant GPU for those. Sure earlier will run, but they won't run well.

I think it might be related to being WDDM 1.0 driver? I haven't tested other WDDM 1.0 cards recently; or maybe because yes, it's not even a proper DX9 GPU.
from what I was reading WDDM 1.1 makes a significant difference for the desktop windows manager.
GMA 4500 which uses WDDM 1.1 and has DX10 support seems to handle things a lot better with not so high CPU usage like with the GMA4500 I saw 5% usage by dwm.exe in a situation GMA 950 uses around 30-40%.
Technically, GMA900/950/3100/3150 -is- a DX9 compliant GPU. But. Firstly, it's about as basic as a GPU can get. 4 pixel pipelines @ 400MHz. No video acceleration, except very basic MPEG2.

Then there is the whole feature level debacle. The GPU is itself hardware DX9 compliant. But only for SM2. SM3 is handled in software, with all the drawbacks (if you'll excuse the slightly intended pun) that entails. The earlier GMA900 doesn't even have a WDDM driver available. Which was the subject of some gnashed teeth back when Vista launched.
 

SPBHM

Diamond Member
Sep 12, 2012
4,843
69
126
#28
In 7 you can get away with using a XPDM driver, since there is still a GDI+ fallback to the DWM compositor. This is what happens when you disable Aero. Vista has the same, but actually keep a complete copy of both compositors. Which is why 7 runs better in some cases, and is one of the reasons for Vistas higher memory requirement.

This was removed with 8 (pure Direct3D DWM compositor) and later, which is why you almost -need- a WDDM 1.1 compliant GPU for those. Sure earlier will run, but they won't run well.



Technically, GMA900/950/3100/3150 -is- a DX9 compliant GPU. But. Firstly, it's about as basic as a GPU can get. 4 pixel pipelines @ 400MHz. No video acceleration, except very basic MPEG2.

Then there is the whole feature level debacle. The GPU is itself hardware DX9 compliant. But only for SM2. SM3 is handled in software, with all the drawbacks (if you'll excuse the slightly intended pun) that entails. The earlier GMA900 doesn't even have a WDDM driver available. Which was the subject of some gnashed teeth back when Vista launched.

is it really technically a DX9 GPU?

I remember that when DX7 was new Hardware Transform and Lighting being one of the key features, which the GMA 950 lacks (even 3dmark 2001SE runs in software T&L with the 950, like it does for DX6 cards, but unlike for those, it runs the Nature test, which uses DX8 shaders)

DX8 required Pixel and Vertex Shader, now the GMA 950 does support Pixel Shader 2.0 via hardware, but Vertex Shaders are done via software, and it can do VS 3.0 via software, PS 3.0 via software is not supported AFAIK, I never found anything that requires SM3.0 and works with the 950.

now this gives it some compatibility issues with games, like when I tried "RallisportChallenge" (DX8 game I think) it refused to work because of the lack of hardware T&L, and with Morrowind it refuses to enable Pixel Shader for example (I think it treats the GMA 950 as a DX6 GPU), both of these worked perfectly fine with the GMA 4500 which can do VS and T&L via hardware.
 

Insert_Nickname

Diamond Member
May 6, 2012
3,587
128
126
#29
is it really technically a DX9 GPU?

I remember that when DX7 was new Hardware Transform and Lighting being one of the key features, which the GMA 950 lacks (even 3dmark 2001SE runs in software T&L with the 950, like it does for DX6 cards, but unlike for those, it runs the Nature test, which uses DX8 shaders)

DX8 required Pixel and Vertex Shader, now the GMA 950 does support Pixel Shader 2.0 via hardware, but Vertex Shaders are done via software, and it can do VS 3.0 via software, PS 3.0 via software is not supported AFAIK, I never found anything that requires SM3.0 and works with the 950.

now this gives it some compatibility issues with games, like when I tried "RallisportChallenge" (DX8 game I think) it refused to work because of the lack of hardware T&L, and with Morrowind it refuses to enable Pixel Shader for example (I think it treats the GMA 950 as a DX6 GPU), both of these worked perfectly fine with the GMA 4500 which can do VS and T&L via hardware.
Far as I remember (could be wrong, its been a while) T&L has always been software based on pre-Gen4 IGPs. I suppose you could argue it's not DX9 compliant then, but Intel list, and provide drivers, as such. That's the real issue with pre-Gen4 GPUs. They rely on SW to assist in some of the graphics pipeline, which leads to horrible performance, especially with slow CPUs. Which is usually what IGPs where bundled with. Figures. It's not quite as bad as "Extreme Graphics (2)", those couldn't even reliably handle GDI+ compositing when the CPU was loaded. Couple with a **** RAMDAC for output, and you get the idea.

Another issue is simply driver support. In the past, games were very much an afterthought in Intel drivers, with apparently little regard beyond "does it run?"

Gen4 was Intels turning point with GPUs. A lot of modern features finally got baked-in along with unified shaders. They're still using the basic design for everything newer.
 

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