SLi graphics cards

A question about these SLi graphics cards...
I've seen them on a few notebooks now but what I'm unsure about is what the point of them is. Some notebooks have 2 x 256mb graphics cards, why don't you just have 1 x 512mb graphics card? I cant quite see the benefit? Also, does a 2 x 256mb card give you the ability to play games that require 512mb graphics cards? Please help!!! Im tres confuzzled!

 

There really is no benefit, other than the fact that they could market their notebooks as "SLI", which sounds cool.

Given that SLI is only about 70-80% efficient in most benchmarks, there's really no reason to get it unless you were going top-of-the-line.

Also I'm not sure if this is still the case, but my 7950 GX2 had 2x 512 memory, but it only utilized half of it in games. It also did not support dual monitors, which was annoying. Although nVidia may have fixed it since I last used SLI.

 

It's not just having double the memory. There's also another GPU.

I wouldn't get it. It's really expensive, the battery life is poor, the heat output is great, and the performance difference varies from -5% to +60%. It should be at least +95% for every game if you have 2 graphics cards.

 

Yeah but the performance is based on whether or not the game supports SLi. So it's not the cards' fault, it's the games that are not designed for multiple gpus.

 

All games support SLI...

SLI is using 2 GPUs as one. Your game will recognize it as 1 GPU.

 

Ok then, so its best just to have a singe graphics card with lots of memory, the battery life would be an issue for me! What I can't quite understand is whenever I read reviews of gaming notebooks on here, the battery life tends to be rubbish, and who ever is writing the review usually says "Seeing as this is a gaming notebook its probably going to be on a desk all day anyway" or something similar. Well I've got news for them... Just because its labeled a 'gaming notebook' it doesn't mean that nothing but gaming happens on it, I like gaming, but I also spend quite a bit of time just browsing the web! What I'd love is a gaming notebook, but with pretty good battery life as well, anyone know of any?

 

Uhh gaming notebooks have very power intensive graphics cards, fast hard drives, higher clock processors, big bright screens, and therefore drain a boatload of battery.

You're not going to find a legit "gaming" notebook that has a good battery life.

 

well if you have a 9-cell battery and your not doing anything gpu/cpu intensive like gaming(those consume most power) then you should have a decent amount of battery life, but generally when gaming you should always have it plugged in. As for notebooks, get one with a 8800GTX, its a very powerful and efficient card, i can't reccomend any at the moment with great battery life but at a minimum any new notebook will have an hour and a half or so of battery life.

 

no they dont

 

Well... my notebook can last up to 5 hours when doing normal tasks, like typing documents, or light internet surfing and chatting. You have to set brightness/volume to low, of course. I'm pretty sure any gaming notebook would have decent battery life when doing normal tasks like this, but when you use them to really game, you're going to want them plugged in.

 

As noted, they don't. You can see our SLI gaming article here:
http://www.notebookreview.com/default.asp?newsID=4121

Personally I do not feel that SLI technology is worth it. You are better off going with a single, more powerful card. Take a look at the Sager NP5792 with the 8800M-GTX.

 

Very good card. But, er uhm, isn't that a desktop card?

Edit - Nevermind. Believe you meant 8800 M GTX.

 

Right-o, thats the info I was really after, I'm just after a future proof laptop & I thought a gaming notebook would be the way to go as they tend to have the better graphics cards, CPU's, hard rives etc. But as I said the battery life was an issue (did I say that actually? ... Well it is!!), but if you can get a decent-ish battery life when just doing web-browsing & chatting etc, then thats good enough for me!!

 

I'm not sure why SLI is so screwy on your computer, but based on the way it was designed, it should always boost performance. It offers 2 rendering and 1 antialiasing method, so the technology will be used by ALL games one way or another, although performance boosts will vary.

http://en.wikipedia.org/wiki/Scalable_Link_Interface

 

Well the game has to be specifically programmed to take advantage of 2 gpus, otherwise if it's an old game it will just see and use only 1 gpu.

It's the same with dual core cpus. Just cuz you have multiple cores doesn't mean your software will run faster. They program has to be designed to work with multicores.

 

doh! I always do that. Good catch.

 

No they are not the same...

Your nVidia drivers tell the 2nd GPU what to do, and it's programmed to give you the best performance boost out of the 3 possible options.

I have read that "in extremely rare cases" do SLI actually lower FPS. You could think of it as bugs in nVidia's drivers. The 2nd GPU is still being used and pushed. It just doesn't result in higher FPS.

Multi core CPUs in gaming is completely different.

 

This is false. Sli is pushed by Nvidia and it's their driver that utilizes the technology and not the game. ei. It's not the game developers responsibility if SLi works or not in their game, it's nVidia's.

Essentially, with every release of an upcomming 'hit' game like crysis, bioshock, or UT3, nVidia releases new drivers because the previous driver did not support the game fully in SLi. You could turn on SLi even without updating your driver, but it wouldn't be as optimized as it would using the newer driver and hence, bugs, artifacts, crashes, etc, could occur.

Sli is for gamers who DEMAND top performance all the time and it is possible to see a 2x increase in FPS, though rare, but typically, you can expect a 60-75% increase in a game.

Examples:
3dMark06: single GPU: 5600 SLI: 8700
Bioshock Max setting 1900x1200: Single GPU: 42 FPS SLI: 60+
UT3 Max Settings 1900x1200: Single GPU: 45 FPS SLi: 60-75fps

Battery life on an SLi gaming notebook will on average only net you 1 hour of battery life and that's just surfing the web or working with Office with the lowest tolerable LCD brightness.

Also, hardly anyone mentions this, but a power brick for an SLi gaming notebook is HUGE, and is often larger than an 8oz soda can and can weigh up to 4lbs. There are no slim and light power bricks for SLi gaming rigs.

Lastly, like most people have said, an SLi gaming laptop isn't really worth it. You can get a top of the line gaming rig for $1000 less than a top of the line SLi gaming notebook. If you need to be mobile like I do but don't want to sacrifice any performance, then yes, an SLi notebook could be for you.

 

This is a quote from Chaz's review of the Toshiba Satellite X205-SLi3. Doesn't that quote suggest that games have to support SLi or not themselves?

 

No. You see, the games tested were all newly released games and nVidia often comes out with newer optimized profiles specific to certain games. nVidia does provide a generic SLi profile for newly released games but as you can see in Chaz's review, it can be hit or miss.

Had Chad used some older games and maxed out the settings, I'm absolutely certain you would see a performance boost.

Lastly, if you wait a month or two and the above games are retested under SLi with new drivers, I'm 100% sure the outcome of those tests would show an increase in performance under SLi and not the reverse.