SLI and Vista

[whitetigerx7]

For all of you out there with SLI motherboards you may have noticed since your migration to Vista only a few certain motherboard actually support the SLI features of various Nvidia cards on non-nForce motherboards. Well there is a reason.

Back on 2000/XP Windows used a driver sublayer feature called the HAL (Hardware Abstraction Layer) to communicate between driver and hardware. The process of control was such as if the driver did not allow it it wasn't executed. This ensured maximum stability in the system by preventing DHA (Direct Hardware Access) features from creating system instabilities and crashing hardware.

SLI from Nvidia was created to allow 2 or more GPUs on seperate graphics cards over a PCI-E interface to work together but there was a catch. Nvidia still had to utilize the HAL on their motherboard chipsets from the NForce4 and 400 series. Many other chipset vendors like ULI, Intel, and SIS each had a clone of SLI on their motherboards. AMD and ATI made a clone callign it CrossFire, which works very similar and will allow Nvidia boards to operate in SLI in a compatibility mode.

Everything was fine until Vista came along. With Vista came a new type of driver which directly interfaced with the system kernel. In turn one key feature was now gone for good. The HAL. This meant SLI had to be rewritten into the Vista display drivers and nForce drivers. There was a catch though. Unless you had an NForce board you would not be able to utilize the SLI features. This meant non-nForce chipset vendors had to get a special nForce controller chip on their non-Nvidia motherboards to make SLI work. Even then most nForce 4 and 400 series still had issues with the drivers and most still would refuse to identify the second card.

So what does this mean for Vista? Not much could be done with the HAL missing for nForce 4 and 400 boards so... Nvidia came up with a solution on the new 600 series of nForce. Create an onboard controller in the chip itself to force SLI in hardware rather than software. Some nForce 4 and 400 boards got the same treatment.

What does this mean for SLI? Well for starters unless you have either an nForce4, 400, or 600 board or an ATI Crossfire board you probably won't get SLI any time soon. So why do some Nvidia display drivers work with SLi and some don't? Simple. Microsoft created a bypass for them. This is why many laptops and certain OEMs have drivers that are not updated very often.

What about ATI? They pretty much did the same thing.

What about Microsoft? Microsoft's driver lab only releases drivers every so often that meet WHQL requirements and even then they sometimes will add or delete features they think are or aren't necessary much like they add an emulation mode for SLI and CrossFire.

So does SLI work on Vista? Yes but it's strictly limited to Nvidia chipsets or chipsets with a special controller from Nvidia, ATI chipsets, or special Microsoft drivers made especially for OEMs with SLI needs.

Edited October 21, 2007 by whitetigerx7

[darkoroje]

I am sorry but you got this wrong. HAL is not gone from Vista, it is the basic layer everything else depends on and is still present. The big change with video drivers is that they run in user space now as a user-mode application. Yes, video drivers needed to be rewritten but not because of HAL but because of display driver architecture changes - you can read more about this on MSDN.

SLI is XP did not work on a non-nVidia chipsets. Yes, there were some hacked drivers that would allow SLI on 975x chipset, but they were never supported by nVidia. So please get your facts straight.

[whitetigerx7]

No I am right. I read the facts at Nvidia.com and as well as other websites that do reviews and such like guru3d and anandtech and other places. As for HAL, read more at MSDN into the HAL. It IS gone from Vista. Vista uses a new type of HAL that operates highly differently from the XP version. The new HAL operates at the kernel level to allow greater flexibility among the user groups but there are vast differences in how hardware and software interact. Drivers operate now at a kernel level instead which does give more support to the user groups but cuts down on what can be done in terms of hardware manipulation. This is why Creative saw EAX get flushed down the toilet from DirectSound3D and why they scrambled to get OpenAL and ALchemy out and more actively supported.

As for hacked drivers getting support from Nvidia, dude... Nvidia would never support a hacked driver anyway. DUH! IT'S HACKED!

Highly advise you next time you want to play the know-it-all-noob card, make sure you have the facts straight and read further into what was being said and maybe even summarized.

[Guyver1]

one minute you say HAL is gone, then you say vista has a new 'type' of HAL. which is it? either there IS a HAL or there isnt.

nVidia are the ones who actually supply the hacked drivers, so they DO actually support it.

the next bit is more XP/SLI related than vista, but still applies to vista from a hardware/driver level regardless of HAL or no HAL.

Fact is nvidia have entered into agreements with other chipset manufacturers to allow SLI to work on non nvidia nForce chipsets (simply because nvidia dont produce a competitive, thermally sufficient mobile chipset), and as such they have to provide drivers for that very agreement (this applies to notebooks not desktops). nVidia are quite happy to take all the excellent positive publicity these laptops take on reviews but once the customer happlily hands over £2500 are then quite happy to turn the other cheek and not bother keeping those products upto date. That smacks of bad business practice and shockingly poor custmer service/support.

nvidia arent entirely to blame here, laptop manufacturers need to stump up some guilt here as well as they have the power to speak to nvidia and request updated driver code so they can release newer versions (im talking about SLI locked drivers, we all know normal single GPU solutions can use any driver they like with a modded inf from this website, also contrary to your theory that SLI is simply an .inf modifiaction is rubbish, the admins here who have looked into SLI for me can confirm that it is not as simple as a modified INF)

nvidia are deliberately locking their drivers (sometimes even on their own nforce hardware, not just competitors hardware) to create a monopoly on what hardware can use SLI, this is just outright wrong. This has NOTHING to do with them protecting their SLI technology. Its fact that SLI works on ANY motherboard that can run 2 GFX cards at same time. what stops this hardware 'standard' working is locked drivers, and nothing else.

[whitetigerx7]

SLI doesn't work on every motherboard! If you have an Intel chipset with 2 x16 PCIe slots that doesn't guarantee SLI compatibility! Same goes with SiS, VIA, or AMD/ATi motherboards. Multiple PCIe x16 slots do NOT equal SLI.

SLI was developed for Nvidia nForce boards EXCLUSIVELY!!! What part of that do you NOT understand? ULi was the only non-NVidia chipset developer that utilized SLI and they did it by hacking drivers. Nvidia filed a lawsuit against them and won because they were using technology that they did not have rights to. SLI technology is owned by Nvidia and is NOT licensed to any 3rd party vendors. Read SiS, VIA, AMD, and other vendors websites and see what they have to say about SLI.

SLI was developed to utilize two Nvidia GeForce cards over a PCIe bus using nForce 4 SLI enabled or later chipset technology.

FYI there are non-SLI chipsets produced by Nvidia that still have two x16 PCIe slots. You can plug two PCIe GeForces into it that are SLI compatible but they still will not do SLI because the motherboard wasn't designed to do so. There are NForce 4 motherboards and there are NForce4 SLI motherboards. Same chipset? yes, but they operate completely different when using two graphics cards.

As far as the HAL... The HAL on Vista is not exactly what the HAL was on 2K/XP. It's named the same because it does what the previous did but they operate entirely different. The one from 2k/XP operated on the API layer. The one in Vista operates at the kernel level. Both allow software to interface with hardware but the new one has tighter restrictions on what can and can't be done.

Guyver, word of advice. Alienware is NOT the best vendor for laptops out there and if they aren't fixing your issue there are alternatives such as going shopping for a newer model of laptop with fully supported SLI on authentic NVidia NForce chipsets.

This was taken from SLIZone's website:

Do you have dedicated hardware for NVIDIA SLI technology or is it just software?

Yes. NVIDIA GPUs combined with an NVIDIA nForce® SLI motherboard (which ships with the proprietary NVIDIA SLI connector) are the necessary building blocks for the SLI platform. Dedicated scalability logic in each GPU and a digital interface between GPUs (the SLI connector) enable this logic. In addition, a full software suite of advanced rendering algorithms provide the best image quality.

Here are two certified SLI technology notebooks so either go buy one or live with Alienware's half-assed hacked drivers:

http://www.toshibadirect.com/td/b2c/cmod.to?coid=-33936

http://www.cyberpowerpc.com/system/Xplorer_X5-5850_Notebook

[darkoroje]

No I am right. I read the facts at Nvidia.com and as well as other websites that do reviews and such like guru3d and anandtech and other places. As for HAL, read more at MSDN into the HAL. It IS gone from Vista. Vista uses a new type of HAL that operates highly differently from the XP version. The new HAL operates at the kernel level to allow greater flexibility among the user groups but there are vast differences in how hardware and software interact. Drivers operate now at a kernel level instead which does give more support to the user groups but cuts down on what can be done in terms of hardware manipulation. This is why Creative saw EAX get flushed down the toilet from DirectSound3D and why they scrambled to get OpenAL and ALchemy out and more actively supported.

As for hacked drivers getting support from Nvidia, dude... Nvidia would never support a hacked driver anyway. DUH! IT'S HACKED!

Highly advise you next time you want to play the know-it-all-noob card, make sure you have the facts straight and read further into what was being said and maybe even summarized.

I actually write Windows device drivers and low-level network software as part of my job, and have been doing so for the past 10 years. I do not usually respond to posts like this but yours is so full of wrong information that I had to say something. It is obvious from your posts that you have no idea how drivers work or what the function of HAL is. Drivers have always operated at the kernel level, the big change in Vista is that display drivers now work in user-mode. They have nothing to do with user groups. And Creative had problems because Microsoft removed part of DirectSound API, nothing to do with drivers.

[Guyver1]

SLI doesn't work on every motherboard! If you have an Intel chipset with 2 x16 PCIe slots that doesn't guarantee SLI compatibility! Same goes with SiS, VIA, or AMD/ATi motherboards. Multiple PCIe x16 slots do NOT equal SLI.

SLI was developed for Nvidia nForce boards EXCLUSIVELY!!! What part of that do you NOT understand? ULi was the only non-NVidia chipset developer that utilized SLI and they did it by hacking drivers. Nvidia filed a lawsuit against them and won because they were using technology that they did not have rights to. SLI technology is owned by Nvidia and is NOT licensed to any 3rd party vendors. Read SiS, VIA, AMD, and other vendors websites and see what they have to say about SLI.

SLI was developed to utilize two Nvidia GeForce cards over a PCIe bus using nForce 4 SLI enabled or later chipset technology.

FYI there are non-SLI chipsets produced by Nvidia that still have two x16 PCIe slots. You can plug two PCIe GeForces into it that are SLI compatible but they still will not do SLI because the motherboard wasn't designed to do so. There are NForce 4 motherboards and there are NForce4 SLI motherboards. Same chipset? yes, but they operate completely different when using two graphics cards.

As far as the HAL... The HAL on Vista is not exactly what the HAL was on 2K/XP. It's named the same because it does what the previous did but they operate entirely different. The one from 2k/XP operated on the API layer. The one in Vista operates at the kernel level. Both allow software to interface with hardware but the new one has tighter restrictions on what can and can't be done.

Guyver, word of advice. Alienware is NOT the best vendor for laptops out there and if they aren't fixing your issue there are alternatives such as going shopping for a newer model of laptop with fully supported SLI on authentic NVidia NForce chipsets.

This was taken from SLIZone's website:

Here are two certified SLI technology notebooks so either go buy one or live with Alienware's half-assed hacked drivers:

http://www.toshibadirect.com/td/b2c/cmod.to?coid=-33936

http://www.cyberpowerpc.com/system/Xplorer_X5-5850_Notebook

Quite incredible!!

Your 2 'SLI certified' laptops BOTH use Intel chipsets, EXACTLY the same as the Alienware m9750. Therefore they BOTH use an n100 chip supplied by nVidia, EXACTLY the same as the Alienware m9750. Therefore your 'SLI certified' laptops will BOTH have the same driver/SLI issues that the m9750 has.... unlocked drivers supplied by NVIDIA to the OEM for inf customisation based on each laptop's requirements.

you contradict yourself continuosly and your only 'evidence' is nvidia marketing information.

SLI was developed for Nvidia nForce boards EXCLUSIVELY!!!

then you contradict yourself in your very next sentance:

ULi was the only non-NVidia chipset developer that utilized SLI and they did it by hacking drivers

this quite clearly proves that SLI works on non nforce SLI chipsets, and that nvidia do indeed lock their drivers. I mean are you deliberately ignoring your own words?. Tomshardware even verify this in their latest Alienware/Dell review here - http://www.tomshardware.co.uk/XPS-M1730-Al...ew-29685-4.html (bottom of the page)

Also:

SLI was developed for Nvidia nForce boards EXCLUSIVELY!!!

wrong, SLI was developed exclusively for PCI Express, from the tech they bought from 3dfx, which worked on ANY old PCI board regardless of chipset and needed 3dfx drivers. nVidia's business model is 'how do we stop competitiors from using this PCI Express technology on motherboards without our chipsets?' easy, we'll lock our drivers so that our drivers only install the SLI code when the driver detects one of our nforce SLI chipsets.

When it comes to laptops using intel chipsets, nvidia supply the n100 chip and unlocked drivers to the OEM so that SLI works.

perhaps you should do some proper research rather than just quoting nVidia marketing propaganda.

[®®®]

Isn't this interesting topic meant to be a mature discussion instead of accusing each other of being false?

[Guyver1]

even the most qualified and intelligent of scholars/professors will make accusations of false reporting, bad research, out right lies :)

be thankful it hasnt degenerated into petty name calling :)

discussion by its very nature is the presentation and questioning of sometimes contradictory data, its up to both sides to be open minded enough to explore all avenues and be big enough to admit they could have been wrong.

everything i've researched so far quite clearly tells me that SLI is NOT bound to nforce SLI chipsets only.

[Guest John]

Just loaded 163.75 Vista drivers on Gericom Hollywood sli,(2x7800)used .inf file (Pieter's INF version 3.232, cheers ) from this site, seemed to be no difference at first, but loaded up NHancer Utility, and bingo.. nvidia sli icon and SLI detected & SLI Enabled and all the setting for SLI/SLI Mode/SLIDX10, just need to find out how to use NHancer now, fantastic site, perhaps Alienware M9700 owners can also get there babies to work

[mobilenvidia]

Wonder what nHancer does to enable SLI :)

[Guyver1]

funnily enough i downloaded the latest nhancer last night,

i might do some more driver experimentation tonight/over the weekend

[mobilenvidia]

I donwloaded it too, and it's still a profile editor, I can't see how it would enable SLI.

it does of course have SLI profiles and the only place it could do it would be here.

[whitetigerx7]

nHancer enabled SLi on a non-Nvidia motherboard... hmmm...

I am going to recheck my INFs again. Maybe I missed something...

[whitetigerx7]

Hate to double post and reply to myself but I did some digging about the nForce 100 chip.

Intel and Nvidia came to an agreement with some of their "customers" like Alienware by providing them with specialized Driver Development Kits that had code for the nForce 100 written into the driver. These are totally separate builds of drivers that are compiled by the distributors and no one else, not even Nvidia. I failed to see why at first but then as a lightning bolt, it hit me. Licensing issues and fees. Basically this means unless Nvidia sees fit to provide an updated DDK kit to the manufacturer of the motherboard distributors, no new drivers that will detect and enable the nForce 100 chip will be released.

The real side question is now what about a separate driver to enable the nForce 100 SLI chip? Simply put... it can't be done due to the design. This follows the same path as to what happened to the 3Dfx Voodoo5 6000 AGP and the HiNT PCI-to-PCI bridge chip on NT based operating systems. It's the same issue as writing a driver to operate a PCI-to-PCI bridge chip over an AGP bus. No 3dfx driver for Windows 2000/XP was ever written with the HiNT enabler code so basically it would not work except on 98SE/ME which had no HAL to control and monitor features like that.

This also means unless the chip is actually not part of the bus itself, which is not possible due to design, no driver can be written for it unless it's written into the actual video card driver. Basically this classes the nForce 100 SLI chip as simply this: An "SLI over PCIe-to-PCIe bridge chip". For it to work, drivers using the device over the bus must have the code written into them to enable it over the bus and make it work because over the bus it becomes part of the graphics card per say.

[Guyver1]

seems to me that the n100 chip and portions of the nforce chipset are nothing more than simple hardware dongles, same as the hardware dongles that you get with AutoCAD. no dongle, no software, in the case of nvidia, no dongle, no SLI.

I've already phoned Alienware to complain and start a return process, I've only had this laptop 3 months, after paying £2300 for it i feel cheated. I waited patiently after a phone call to their tech support after I'd just bought it and was reassured that drivers were comming, i then spent the last 3 months here and around the web doing some research, trying to get drivers to work, and all along Alienware witheld vital information that if given that information before I bought it, I basically wouldnt have and would have built my own desktop gaming rig.

thankfully the laptop was bought on a buy it now pay January 2008, so as of yet its not been paid for, I''ve even paid for a 3 year warranty, after some 1st class customer complaining today I'm hoping they will cancel the finance agreement and take the laptop back, otherwise it'll be all out consumer war

[whitetigerx7]

I'm getting kind of leery of SLI anyway on non-nForce boards anyway. And with some manufacturers you have no idea what motherboard you might even be getting. Alienware used to tell you. When I had my m5500 before it keeled over and died I remember when I ordered it they said I was getting a Intel 945 motherboard right on the ordering page. Now it's nothing said at all.

I think for now and I honestly hate to say it. Unless you have an nForce board and maybe even a desktop unit. SLI might not be worth the extra cash if you have no idea if it is a certified board or one with a nForce 100 that uses specialized drivers.