Partial precision to be removed from DirectX 10

Vikingod · Jan 30, 2006, 03:02 PM

"It's been the cause of many a debate and much controversy since its inclusion in the DirectX 9 specification, but it appears that with Windows Vista on the horizon, and a new version of DirectX to appear alongside it, that partial precision hints (aka FP16) are finally dead as of DirectX 10.

This probably won't come as much of a surprise to most, as we have already seen a tightening of the precision requirements between Shader Model 2.0 and 3.0 as FP32 became mandatory for such parts, so it seems that Shader Model 4.0 will simply finish the job by removing the requirement of or support for partial precision.

If nothing else, this change should make life somewhat easier for developers, who now only have to worry about targeting a single precision, rather than spending swathes of time chopping and changing shaders to see if the use of FP16 can improve performance without adversely affecting image quality. Now the performance penalties are much lower than we have seen in the past (although they are still present on existing parts, as we've seen in a number of our recent reviews), leaving FP16 behind entirely seems like a logical progression from here. "
__________
Source: Elite Bastards

The_Neon_Cowboy · Jan 30, 2006, 04:59 PM

good ridance that should kill off some unfair optuizations

ChrisW · Jan 30, 2006, 07:43 PM

It will not stop nVidia from replacing shaders with hand made shaders with FP16 hints with their drivers.

Necrosis · Jan 30, 2006, 08:23 PM

If they do that then their drivers will never get certified, and doesn't Vista have issues with non-certified drivers? Also Nvidia's latest card is "supposed" to have SM 4 so it might be a moot point???

ChrisW · Jan 30, 2006, 10:08 PM

They have been doing shader replacement forever and said they would continue to do it whenever possible, so I don't see why they would stop. Their shader recompiler does the job for them and it will even replace entire shaders with hand written shaders when needed.

Jan 30, 2006, 03:02 PM	#1
Vikingod Int'l Fish Liaison Join Date: Jul 2004 Location: By the light of lamp I sit and type... Posts: 16,187 Rep Power: 109 System Specs	Partial precision to be removed from DirectX 10 "It's been the cause of many a debate and much controversy since its inclusion in the DirectX 9 specification, but it appears that with Windows Vista on the horizon, and a new version of DirectX to appear alongside it, that partial precision hints (aka FP16) are finally dead as of DirectX 10. This probably won't come as much of a surprise to most, as we have already seen a tightening of the precision requirements between Shader Model 2.0 and 3.0 as FP32 became mandatory for such parts, so it seems that Shader Model 4.0 will simply finish the job by removing the requirement of or support for partial precision. If nothing else, this change should make life somewhat easier for developers, who now only have to worry about targeting a single precision, rather than spending swathes of time chopping and changing shaders to see if the use of FP16 can improve performance without adversely affecting image quality. Now the performance penalties are much lower than we have seen in the past (although they are still present on existing parts, as we've seen in a number of our recent reviews), leaving FP16 behind entirely seems like a logical progression from here. " __________ Source: Elite Bastards __________________ *How You Can Help DriverHeaven By Using Digg*

Jan 30, 2006, 04:59 PM	#2
The_Neon_Cowboy HardwareHeaven Extreme Member Join Date: Dec 2002 Location: U.S.A. Posts: 16,009 Rep Power: 90 System Specs	good ridance that should kill off some unfair optuizations __________________

Jan 30, 2006, 07:43 PM	#3
ChrisW DriverHeaven Senior Member Join Date: Mar 2003 Posts: 332 Rep Power: 0	It will not stop nVidia from replacing shaders with hand made shaders with FP16 hints with their drivers.

Jan 30, 2006, 08:23 PM	#4
Necrosis HardwareHeaven Extreme Member Join Date: May 2002 Location: Ohio Posts: 8,838 Rep Power: 129 System Specs	If they do that then their drivers will never get certified, and doesn't Vista have issues with non-certified drivers? Also Nvidia's latest card is "supposed" to have SM 4 so it might be a moot point???

Jan 30, 2006, 10:08 PM	#5
ChrisW DriverHeaven Senior Member Join Date: Mar 2003 Posts: 332 Rep Power: 0	They have been doing shader replacement forever and said they would continue to do it whenever possible, so I don't see why they would stop. Their shader recompiler does the job for them and it will even replace entire shaders with hand written shaders when needed.