nHancer: Can't finish new version b/c nVidia added a checksum

[Grestorn]

Hi everybody,

I guess some of you have been wondering when the next version of nHancer will be available. Well, it's about to be finished, but I've got a serious problem I can't solve by myself.

Maybe somebody, who has some insider contacts to nVidia could help me out there. Here's the problem:

The DX10 SLI compatibility values for each games are not read from the registry like it has been done for all the other values so far. The driver reads this value directly from the nvapps.xml in system32 (or syswow64 in Vista64).

That wouldn't be a problem at all, but the driver only accepts the nvapps.xml file as beeing valid, if it contains a checksum that matches all containes values. Check out the start of nvapps.xml:

<?xml version="1.0" encoding="UTF-8"?>
<FILE>
	<INFO Number="3276289231"/>
	<PROFILESET>
...

This "INFO" Number is the checksum. As soon as you change any numeric value in the nvapps.xml, DX10 SLI stops to work. Also, if you change but one digit of the INFO Number, DX10 SLI will stop working as well. It seems that the driver doesn't accept the whole nvapps.xml file, as soon as the checksum doesn't match.

The problem is: I have no idea how to calculate that checksum. If I knew the algorithm, I could adapt the checksum when changing the file...

BTW, an interesting note is that nVidia's own panel doesn't know how to calculate the number either. Therefor they changed it so it never tries to write the file in System32, it holds a private copy in ProgramData\NVidia (Vista) or in All Users\Application Data\NVIDIA (XP) instead.

nHancer could do the same (in fact the current, unreleased version does it this way), but you couldn't change any DX10 SLI compatibility values then. And I'm afraid that in the future, the DX10 driver might read more and more values from the nvapps.xml and none of them could be changed by nHancer. Which would kind of defeat nHancer's purpose.



So, again, if anybody has some insider contacts to nVidia and could forward this plea of help or something like that, I'd very much appreciate that!

Otherwise I fear that nHancer will come to an end soon...

[Phyxion]

Well, if I read it like this, you cannot change any DX10 SLI profile? I mean, if you change something, it needs to be stored somewhere.

[Grestorn]

Originally Posted by FnFGoT

Well, if I read it like this, you cannot change any DX10 SLI profile? I mean, if you change something, it needs to be stored somewhere.

Yes, it's stored in the nvapps.xml only. Nowhere else. Not in the registry like everything else.

[Phyxion]

Originally Posted by Grestorn

Yes, it's stored in the nvapps.xml only. Nowhere else. Not in the registry like everything else.

"an interesting note is that nVidia's own panel doesn't know how to calculate the number either."

Then how can NVIDIA Control Panel store and retrieve the changed settings?

[Grestorn]

Originally Posted by FnFGoT

"an interesting note is that nVidia's own panel doesn't know how to calculate the number either."

Then how can NVIDIA Control Panel store and retrieve the changed settings?

It doesn't. It reads and writes its own copy in c:\programdata\nvidia which is independent from the one used by the driver (only for DX10 SLI, mind you!) in c:\windows\system32 (or syswow64).

[nekrosoft13]

Grestorn

how about current version 2.2.3? I know that by defualt it doesn't even find nvapps.xml in SysWOW64 folder in vista64.

My question is should it be hard linked to nvapps.xml in SysWOW64 folder or to ProgramData\NVidia folder?

Currently I don't use DX10 SLI so its not a problem for me. Just need the other profiles to work.

One thing i did notice with current 2.2.3 version when i change an option in nHancer and go back to control panel settings are different.

[Grestorn]

Originally Posted by nekrosoft13

Grestorn

how about current version 2.2.3? I know that by defualt it doesn't even find nvapps.xml in SysWOW64 folder in vista64.

My question is should it be hard linked to nvapps.xml in SysWOW64 folder or to ProgramData\NVidia folder?

Currently I don't use DX10 SLI so its not a problem for me. Just need the other profiles to work.

One thing i did notice with current 2.2.3 version when i change an option in nHancer and go back to control panel settings are different.

Normal profiles will always work if you change them in nHancer, since the profiles are actually read from the registry.

The only exception is the DX10 SLI setting.

So you can continue using 2.2.3. The only problem might be that the control panel doesn't see the changes made in nHancer (depending on the Forceware version and OS you're using). But the profiles will work nevertheless.

[nekrosoft13]

ok, but should i create a hard link to nvapps.xml in SysWOW64 folder or to ProgramData\NVidia folder?

because in new driver puts the nvapps.xml in SysWOW64. But then there is another copy in ProgramData\NVidia. While nHancer looks for the file in system32 folder.

[Grestorn]

Originally Posted by nekrosoft13

ok, but should i create a hard link to nvapps.xml in SysWOW64 folder or to ProgramData\NVidia folder?

because in new driver puts the nvapps.xml in SysWOW64. But then there is another copy in ProgramData\NVidia. While nHancer looks for the file in system32 folder.

Better copy the file to system32. If you create a link, nHancer will change the file in syswow64 (through the link) as well, which would disable SLI in DX10. If you don't use SLI, it's really of no consequence at all. It doesn't really matter whether the files in system32, syswow64 and ProgramData are in sync as long as you don't use the panel for changing profiles.

BTW, the panel reads from system32 if it can't be found in ProgramData. Even though the setup of 162.50 places the file in SysWOW64 (and the DX10 driver reads from there as well). This causes 162.50 to display an empty profile list in the standard panel ...

Quite chaotic, the current state of driver and panel development...

[jabloomf1230]

I'm sorry I can't be of much help, but as you know, the <INFO NUMBER="xxx"> entry has been in nvapps.xml for a large number of driver revisions, so maybe someone outside of nVidia has reverse-engineered the checksum algorithm.

Depending on how much attention that you want to attract to this problem, you could email the good people at inquirer.net and maybe they would post a news item on the issue. I'm not sure what nVidia would be gaining by preventing users from developing 3rd party software like nHancer, that alters the DX10 SLI profiles.

It might also be a temporary glitch, since it doesn't appear that <INFO NUMBER="xxx"> entry has ever been used for anything obvious before, for DX9 SLI. And that goes back to the YAPES days.

[Grestorn]

Originally Posted by jabloomf1230

I'm sorry I can't be of much help, but as you know, the <INFO NUMBER="xxx"> entry has been in nvapps.xml for a large number of driver revisions, so maybe someone outside of nVidia has reverse-engineered the checksum algorithm.

Depending on how much attention that you want to attract to this problem, you could email the good people at inquirer.net and maybe they would post a news item on the issue. I'm not sure what nVidia would be gaining by preventing users from developing 3rd party software like nHancer, that alters the DX10 SLI profiles.

It might also be a temporary glitch, since it doesn't appear that <INFO NUMBER="xxx"> entry has ever been used for anything obvious before, for DX9 SLI. And that goes back to the YAPES days.

YAPE... Hehe. There's actually someone who remembers that!

Well, yes of course, the INFO has been there from the beginning, but it never carried any significance as far as I could tell.

I tried to use some contacts to get in touch with the driver team, but I never got any response from them (wasn't my first try). So my guess is, that they don't really care much for nHancer.

Well, I guess I have to live with that. In the end, I might very well be forced to stop working on nHancer, if they keep making it more and more difficult for third party apps to work with their drivers...

[bagman]

On a slightly related matter. Will version 2.2.3 work with the latest nVidia drivers 163.44 ??

cheers