Hybrid SLI

probably buying the new mbp today regardless of if hybrid SLI is possible or not

question for you hackers and pundits:

Do you guys think this will eventually be possible via an official release or a hack? or is it just not possible in the hardware?

windows or osx, don't care which

 

According to Macrumors, Nvidia has come out and said that HybridSLI is not supported in the new MBP. They didn't mention if this is due to hardware or software. I'm hopeful that someone will eventually figure it out, but even so I posted some benchmarks and I got 5800 3dmarks stock without OC or new drivers. Pretty kickass imo.

 

I think that option will be available with Snow Leopard

 

It'd be really pointless to have them in the MBP if they can't benefit from both. Switch for battery life? not convincing enough for me, it's only an hour extra, not like 2 or 3.

Hopefully Snow Leopard or updates in the future will be able to address both card at the same time. I hope it's a software restriction right now as oppose to hardware >.<

 

SLI (hybrid or not) just like Crossfire usually requires cards of comparable performance. 9400M and 9600GT are not of comparable performance. The way that SLI works makes it such that if you pair 2 cards that are disproportionate the end result is more likely decreased speed. At least that's the state of things right now, perhaps it will change thought I doubt it will on current hardware.
What I see as more likely is to use the lesser processor (9400m in this case) for physics acceleration. We'll see

 

5800 is pretty good, what resolution was that at?

 

1280 x 800

 

hey, just to get you up to speed, the new hybrid SLI and a similar crossfire technology from ATI allow you to combine cards of different performance specs. The effect obviously isn't 1:1 additive but it DOES increase performance significantly

 

Well of course cards don't have to be identical but they have to be about same speed.
Check this link from nvidia and you will see:
http://www.nvidia.com/object/hybridsli_notebook.html

I'm not saying it might not change (though I doubt it) but as for now hybrid sli - geforce boost only works on low end cards (9600GT is not one of them). Personally I haven't tried with nvidia but I have tried with ATI 780G and it's the same (only works with lowend radeons 24xx, 34xx, 43xx)

Perhaps I wasn't very clear the first time. Hybrid SLI for nvidia means 2 things:
1.the fact that you can use 2 different cards (one of them integrated) at choice (but separately) to maximise power or minimise consumption
2.what they call geforce boost, or clasic SLI where 2 cards work in tandem for greater performance.
So yes, you can use 9400m and 9600M gt in hybrid SLI but not for extra performance over a single 9600m GT. At least not for now afaik. But if you can show me otherwise I'd be more than happy to read about it

 

Agreed. Hybrid SLi has 2 parts, geForce Boost and Hybrid Power.

The tech we are really talking about here is GeForce Boost, hybrid power enables the seamless switching between IGP and GPU, which it is clear this does not have. (as nvidia says)

GeForce Boost was intended to allow an IGP to supplement the power of a GPU. It is unclear if the MBP has this capability or not. It could be an OS or Driver limitation, but nVidia has just said that it does not have it.

Heres to hoping that the software catches up with the hardware...

http://www.nvidia.com/object/hybridsli_notebook.html

 

You do know the 3Dmark standard is 1280 x 1024, right?

 

lol - the MBP can't even do that res =P

 

Yes, but you're supposed to plug your laptop into an external monitor that can support that resolution, otherwise your results aren't going to represent the machine accurately.

 

So you mean it's not hardware restriction for the boost right? If it's software hopefully there'll be something to implement this, official or not ; )

 

Maybe it could be done using SFR (split frame rendering) technique but my guess is it would be very hard to program though possible. AFR would most certainly decrease performance since the weaker card would hold the more powerful card back. SLI doesn't work in all games as it is so I'd imagine getting geforce boost to work on cards of very different power is not right at the top of their priorities. Plus we're talking apple here. They don't really care much about games.

 

I don't mean that it's not a hardware restriction. It could be, we don't know.

Everyone is hoping that it is a software / driver / OS restriction, but nVidia will not tell us either way.

They just gave this explanation not saying if hardware or software is to blame.

 

Seriously? My Dell Latitude D420 runs at 1280x800!

 

Think you missed the point.

Widescreen monitors don't do 1280x1024... MBP uses 1440x900.

 

Then how are you supposed to benchmark them? That resolution still isn't that great, it's lower than my D610.

 

The resolution is perfect IMHO. I've had laptops (sager) with 1600x1200. I thought that was terrible. Everyone hated looking at it too.

I wouldn't mind seeing the MBP bumped up a bit, but not to something retardedly extreme.

You can benchmark just fine at 1440x900. If you change 3dmark to do tests at 1440x900, I believe you can compare the results to others running under 1440x900.

Besides, 1440x900 is the common desktop resolution for new monitors now.

 

I was kind of hoping the new MBP would support Hybrid SLI...

I think I'm going to hold off on buying a new MBP until next year. What I'm hoping for is the CPU to be updated to Intel's upcoming Nehalem line and Hybrid SLI support. That will be a beast.

 

I also prefer 1440x900.

And multiplying it out 1440x900 (1.30 million) actually has a similar number of pixels to 1280x1024 (1.31 million). Hardcore benchmarkers will quibble, but scores obtained at 1440x900 should be comparable to 3DMark standard at 1280x1024. Fluctuations between different driver versions is probably larger than the effect of the pixel count difference.

 

The new MBP will probably support hyrid SLI down the road, as it is a driver issue, not a hardware issue.

I like WSXGA+ better on a 15.4", as you get more screen real estate. But WXGA+ is good for 14.1" displays.

 

It won't support Hybrid SLI, it is a hardware issue. Otherwise, it would work on Windows.

http://nvidia.custhelp.com/cgi-bin/nvidia.cfg/php/enduser/std_adp.php?p_faqid=2243

 

Do you guys think we'll know in a few months after tests are conducted? seems like some people think it's software while other thinks it's hardware. I don't mind if it doesn't have hybrid SLI just as long as both of the gfx card gets taken advantage of somehow (ie. cs4 can address to both). Other wise I think it's kind of pointless to have it in the pro for an additional hr of battery life, but that's just me.

 

Hey i actually did see that chart, but i was holding out the hope that this new igp would enable it (geforce boost) as i don't think there is any specific implementation barrier since the 9600m gt SHOULD include all the necessary hooks for standard SLI in the first place.... (based on a pumped up 8600m gt which was SLI enabled). I guess the only barrier would be the drivers and correct algorithms for calculating the optimal Split frame ratio, which admittedly uses up some processor overhead, but that's why we have dual core.

Hey even if the dump the 9400m igp to physics calculation, that works for me.

Now if the IGP and the discrete 9600mgt share the same PCIE bus lanes and hand off to each other dynamically (on logout), then that's where i could see a hardware problem.

 

YAYYYYYYY

http://gizmodo.com/5067433/confirme...l-gpu-and-on+the+fly-switching-in-macbook-pro

http://blog.wired.com/gadgets/2008/10/macbook-graphic.html


YAYYYYYYYY!!!!

 

^exited?me too

 

When do the next set of nvidia beta drivers come out? Think that HSLI will be supported via lv2g?

 

Don't expect much improve in performance as I've read. Because for Geoforce dual boost the faster cpu has to wait for the slower gpu and since the difference between the two is so great it probably won't be much improvement, and might be a decrease in performance.

 

^sorry,but you are very wrong.

 

Even if that were the case, the clocks are only ~100MHz slower so that shouldn't cause too much latency.

 

I really hope that I am, but can you prove it? I'm all for better performance at some gain of heat, but as of right now geforce boost with the two card doesn't seem like much improvement based on what I read. What I understand is that the boost is 2 gpu running over a task, you can divide, let's say the weaker one 30% and the other 70%. But you can't decide where that 30% will cover. Let's say 30% renders the bottom 1/3 (approx) of a frame. What if the frame top 2/3 is all white and the bottom 1/3 is full of water, then the 1/3 bottom have to be rendered by the weaker card, cause more delay than if it was the stronger gpu.

 

The thing is, the 9600 doesn't support Geforce Boost, it supports Hybrid SLI. I don't have a link but I do have their features chart printed out on my desk at home and one of the things I remember seeing (and being confused by) was this very fact.

edit: Even if it just offloads physics calculations I think that would be a significant performance boost.

 

Isn't Hybrid SLI the Hybrid Power (switch between discrete and integrated GPU) and GeForce Boost? I know that even if GeForce Boost can't be implemented having the ability to address both the GPU at the same time will improve a lot for video rendering, etc. once it's supported (Snow Leopard ftw). I should've been clearer and said not to expect improvement in GeForce Boost portion, my mistake.

 

So why would apply put this is a PC if it has no benefit. Kinda seems pointless to me.

 

Well i just bought one regardless of if geforce boost was possible or not. So if it is, its a big bonus for me even if its only a small boost in performance over 9600m gt solo

I believe the 9400 IGP is about 100mhz slower and has half the pipes so theoretically it could add something around 30-40% boost. CPU overhead, scene rendering specifics (i.e. what is where on the screen) and driver support probably chop that by half. so 15-20% boost? Maybe more if split frame rendering % balance can be dynamically adjusted