NVIDIA SLI & ATI CrossFire - Experiences & Opinions

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FrgMstr

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NVIDIA SLI & ATI CrossFire - Experiences & Opinions / Brent Justice talks about real-world experiences with SLI, CrossFire, and Dell’s 30” LCD. This is a free form editorial that simply gives you our opinions about high-end gaming as we see it today.

We see a very positive trend that is underway. Both SLI and CrossFire are moving into a more mainstream and user friendly environment. We see the niche that SLI pioneered expanding rapidly. Even a novice gamer can now easily setup a NVIDIA SLI platform with little worry. With the GeForce 7950 GX2, dual-GPU performance is the easiest it has ever been; simply install the video card and automatically you will have the performance of two GPUs just as if you were using a single GPU. ATI’s CrossFire is trailing in this department, but we are confident this platform will also mature and evolve, hopefully sooner than later.
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Good read, I found it informative...I'm still learning all about this sort of thing.

What I did know though was that CF was severely lagging behind SLi, in terms of overall usage. Though I do give CF major props for flexibility: the ability to connect two different card types (X1900XTX + X1900XT) as opposed to the exact same ones (2x X1900XTX), does give it an advantage over SLi.

But yeah, SLi is so much easier to use from what I understand.

I guess the best way to sum it up is as such:

One card solution: ATi
Two card solution: nVidia

Oh, and I want a 3007WFP :D :D
 
You guys once again cleared up the BS and made it clear as crystal. Kudo to you guys, I love these kinds of editorials (This, GPU scaling, etc). I actually wish you would do more, but I'm certainly not complaining. A well done job, very well done.

All nVidia needs is some better AF and they will take the whole cake. HQ AF is the one and only reason I would consider red at this point.
 
InorganicMatter said:
You guys once again cleared up the BS and made it clear as crystal. Kudo to you guys, I love these kinds of editorials (This, GPU scaling, etc). I actually wish you would do more, but I'm certainly not complaining. A well done job, very well done.

All nVidia needs is some better AF and they will take the whole cake. HQ AF is the one and only reason I would consider red at this point.
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Don't forget: ATi - HDR + AA...another point for red.
 
As I mentioned in the GX2 evaluation IQ leans toward red right now for a few important reasons.
 
DoomRulz said:
Though I do give CF major props for flexibility: the ability to connect two different card types (X1900XTX + X1900XT) as opposed to the exact same ones (2x X1900XTX), does give it an advantage over SLi.
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The only difference with the XT and XTX is clock and memory speeds, it is the same GPU.

NV also allows you to pair up video cards with different core and memory speeds.
 
Brent_Justice said:
NV also allows you to pair up video cards with different core and memory speeds.
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Different speeds I know...but different cores??? So I could sli a 7900GT with my 256MB XFX 7800 GTX??? (or a 7900GTX for that matter)
 
kuyaglen said:
Different speeds I know...but different cores??? So I could sli a 7900GT with my 256MB XFX 7800 GTX??? (or a 7900GTX for that matter)
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He meant different core speeds and different memory speeds. Not different cores.
 
Brent_Justice said:
On my test platform I have an open motherboard that is sitting flat on my desk. The video cards are therefore not screwed into anything, they just sit there.
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Brent, as much testing as you do you should get Kyle to spring for some of those new Top Deck Tech Stations when they come out.
 
With a single video card the framerate is constant to however the GPU performs, but with dual GPUs it sometimes jumps up and down as the GPUs load balance, and a delay in this can cause you performance at a critical moment.
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Im not the best at English, but isnt that ... like... wrong?

Kyle - Word left out. Should read "performance LOSS," fixed. Thanks.
 
There are several things I like about my old SLI setup, over my new CF setup, and vice-versa. I like NV's profiles better for one thing. I dont get why it takes some peoples PC's so long to launch CCC, mine does it in about one second. After the first initial launch, it takes only about one second.

Overall good article. Both have come a long way, SLI has come farther since it came out, because it has been out longer. Like many (and rumored to do so) CF will make leaps and bounds to catch up with the no more Master/Slave buisness, among other things pretty soon.

InorganicMatter said:
All nVidia needs is some better AF and they will take the whole cake. HQ AF is the one and only reason I would consider red at this point.
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You wouldnt like playable frames at 8x or 16x SLI AA? ATi's Super AA is much, much, much faster than NV's SLI AA. Which if memory serves, is due in part to the dongle?
 
Ok, SLI is easier to install but it's not like crossfire takes a whole lot longer. 30 secs compared to 2 mins. Big deal.

Not to mention that it's a 1 time thing. Once it's installed you won't be thinking about how long it took you to install the damn things.

Where its @ is benches. SLI has the upper hand in some situations -- mostly faster FPS. But ATI has the upper hand in higher quality settings -- higher resolutions with higher amounts of AA.

The drivers are the only place where there is a clean cut winner. Nvidia has many game profiles whereas ATI has very few.
 
DoomRulz said:
Don't forget: ATi - HDR + AA...another point for red.
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Well, HDR+AA isn't an option for most people, since it's only realistically playable on CF X1900XTX's. Most of us can't even afford a 7600/X1600 :)
 
I actually read the entire thing. I liked it a lot and I hope that you do more in the future. I liked it b/c it was like I was sitting down with you guys and were just telling me how and why you liked the different products from a techie's perspective.
 
fallguy said:
There are several things I like about my old SLI setup, over my new CF setup, and vice-versa. I like NV's profiles better for one thing. I dont get why it takes some peoples PC's so long to launch CCC, mine does it in about one second. After the first initial launch, it takes only about one second.

Overall good article. Both have come a long way, SLI has come farther since it came out, because it has been out longer. Like many (and rumored to do so) CF will make leaps and bounds to catch up with the no more Master/Slave buisness, among other things pretty soon.



You wouldnt like playable frames at 8x or 16x SLI AA? ATi's Super AA is much, much, much faster than NV's SLI AA. Which if memory serves, is due in part to the dongle?
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Just for fun:

X1900 Crossfire Super AA at 14x quality performing faster than nVidia SLi AA at 8x. Besting both 7900 GTXs in SLi and the 7950 Gx2. Simply compare the nVidia 8x number with the ATi 14x from the tables for the appropriate resolutions.

cod8x6sy.gif

cod16x5le.gif


hl28x6gx.gif

hl216x5ae.gif


pier8x6fn.gif

pier16x5xy.gif


For the record I moved from dual XFX 7800 GTs in SLi to X1900 Crossfire and do not regret the move one bit.
 
InorganicMatter said:
Well, HDR+AA isn't an option for most people, since it's only realistically playable on CF X1900XTX's. Most of us can't even afford a 7600/X1600 :)
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Well realistically it's only playable at x1900xtx at HIGH resolutions maybe (although in Oblivion it's quite playable) But at lower resolutions x1600 card can handle it.
 
Neither of these two solutions is CLEARLY better than the other. You have to decide the factors important to you first before picking one, if you're only going to use one. You can always get one of each!

When I made the decision to go SLI, it was November 2005, and CF was just starting. Since CF was immature at the time I went SLI.

Now seven months later, SLI I believe is a more robust solution still, so I would still go that route. The QUAD-SLI, though not official yet does bring gaming to the large monitor crowd, and can be quite impressive.

So here's how I look at it.

ATI PROS:
----------------
Better Image Quality
Better performance in shader intensive games

NVIDIA PROS
------------------
Fastest single slot solution right now
More robust multi-CPU technology

I really think that sums it up well right now. So you have to decide what's more important to you.
 
To waste almost a page of an article bitching about the dongle when the video cards were not properly installed in a computer case, as it was designed for, is rediculous.

I am trying to find the point of this article other than to complain about the dongle and CCC. How that applies to gaming and helps with IQ is beyond me.
 
R1ckCa1n said:
To waste almost a page of an article bitching about the dongle when the video cards were not properly installed in a computer case, as it was designed for, is rediculous.

I am trying to find the point of this article other than to complain about the dongle and CCC. How that applies to gaming and helps with IQ is beyond me.
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Maybe the dongle thing was a bit over the top, as hardware setup is a one time thing, but gamers will spend a great deal of time in drivers control panels, and I do believe that is important.
 
At the moment i think Nvidia is winning the battle but at the same time i would love to see what Ati have in store for us in the future.

The best thing about this is they both are competitors which for us consumers is brill.

They both have to keep on proving to each other and we can benefit, brill. :)

If Nvidia was a monopoly(or ati) , i dont think we would have even made it to two GPUs . So they are very important , i wish there was a few more.
 
Don't listen to these other guys Brent or Kyle. I didn't know anything about the CCC or the dongle and thought both were explained just fine and were given appropriate length within the article. I liked it and thats all that matters :D
 
Ati i believe lost out when they were sorting the whole 360 chip .also at beginning of crossfire people even labelled it as missfire. things have changed now but you still need a master and slave.

The thing i discovered after using sli was that you pay twice the money and only recieve 150% in total instead of 200% ,

Even the retailer told me this when i was buying and advised me to buy a stronger and better card but the thing was that he told me this when i was buying the second one. An expensive lesson

But after the 7950 things have really changed , now you have it all on one card.Plus it uses the slot which you normally would not have used and saves space. (the small pci).

Another thing i learned at the time was bandwidth of the two pci 16 slots which a8n32 -sli boasted of and nobody beleived that it really made a difference but later we learnt that after the 7950 bandwidth is very important especially when you have two sandwiched cards.

There is also two 1600 coming out soon like this.Sandwiched i mean.

:)

Exiting times ahead
 
I fully agree with Brent on most of his points and I pushed him to write this in an open discussion fashion because there is so much that he knows from sheer evaluation expereience that does not get shared in the actual evals. Maybe the part about the dongle is pushing it, but remember this is HIS OPINION, not yours or mine. To express that his opinion about an issue is wasted, if very real to him is unwarranted and rude. He explained that it a minor issue likely to not impact many folks. So jeez, let the guy vent a little for ONCE. The fact is that the dongle is not elegant and not mature, so be it. The only problems I see with it is if you want you box close to the wall....that and it limits you to 3 heads instead of 4, but that is not going to impact much anyone.

I have used both CrossFire and SLI extensively, and I can tell you that with the current CCC solutions, I will never use them on my own box as I run multiple montiors and that means a lot of CCC usage turning CF on and off. With SLI, it requires me to restart whenever I want to use SLI. It is a pain in the ass, but CCC just drives me nuts with all the flashing and locking and general unpolished feel. I think CCC is broken every time I use it from all the odd and long delays. That said, I play less games now because of the pain to reboot SLI every time I want to use it....

Thanks for the heads up on the test carts, I have seen them in the past but the motherboard mount was on the bottom and just not a good answer. I will grab a couple of those and see how they work.
 
The dongle is a bit of a non-issue for me (as cluttered as the wires are beneath my desk, one more that connects to a PC on both ends and doesn't join the tangled nest isn't a big deal IMO), but the inability of users to create custom profiles for Crossfire is a major limitation. ATI may have the better high-end graphics chip on the market right now, but NVIDIA, hands-down, has the better dual PEG implementation (hardware and software).

That aside, though. . . .yeah, Brent's concerns over the dongle's latency/bandwidth struck me as rather green in tone. Crossfire's higher AA modes absolutely crush SLI's higher AA performance, so me thinks bandwidth is being pretty consistently delivered there.
 
John Reynolds said:
That aside, though. . . .yeah, Brent's concerns over the dongle's latency/bandwidth struck me as rather green in tone. Crossfire's higher AA modes absolutely crush SLI's higher AA performance, so me thinks bandwidth is being pretty consistently delivered there.
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Brent and I sat down last week with the two 30" Dells hooked up side by side with SLI and CrossFire configurations. The AA differences you point out did not come across in-game to me at all. I honestly think that AA differences between the two now are a moot point when it comes to real-world experience. If you want to sit and pick it apart, I can surely realize your arguments, but they do not hold water with me in a gaming scenario.

Where there is a glaring difference is with AF. Instances in BF2 and WoW are like night and day between SLI and CrossFire when you have it blow up to rather large resolutions. We even saw some pretty big AF issues in HL2 as well. I can tell you that if I was playing WoW as my primary, game (and I know about 5 million folks are) AND on a big screen LCD, I would not use SLI. NVIDIA's AF has trailed ATI's for some time now, but the differnces on a large screen monitor are shocking. ATI is not without fault, but I would not use a SLI setup for playing WoW on one of them. I think at that point I could put up with all of CCC's shortcomings for better AF. Obviously, this is a minor point now for many folks, but the fact is that it is time NVIDIA got their shit together on their AF technology to be competitive with ATI. Texture crawling and "shimmering" are about to be a major issue for them if they do not correct it soon. Sure the vocal minority has been trumpeting this for a while now, but the fact is that it has not really impacted their sales, but it will soon IMO.
 
Thanks for the good read, learned quite a bit and helped clarify some issues for me. :)
 
Sir its a honour to talk with you in such a forum.

I have just read what you have wrote about the whole Sli setup on a 30" screen and its not one you would opt for , however if it was a quad setup and it was running smooth then would you change your mind or would you still say ATI.

I am saving up for a 30" and after what you have wrote it makes you think.

I have played Quake 4 at 1800 res and i loved it with my 7950 XXX and was quite surprised of the framerate it did too but then i read this.
 
John Reynolds said:
I was talking bandwidth, not image quality. If the dongle and compositing chips were creating a bandwidth limitation then it should show with higher settings.

But, yeah, higher AA modes give diminishing returns on EER, depending on the scene being rendered (high color contrasts along geometry obviously being the most noticeable, but sample patterns aren't exactly optimal for either company's higher AA modes). I'm still wondering if either company will spend the die space implementing some form of stochastic AA support in a future design.
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Sorry I did not get what you were saying. I think the dongle will be long gone by the wayside before it ever is a bandwidth issue. That said, we found plenty of places where AA levels had to be decreased at the high resolutions becasue we were running out of memory buffer on a 512MB card. Yeouch.

Diminishing returns on AA is fully correct and I would rather see both ATI but especially NVIDIA focus on AF for the time being. Are monitors going to move much past 24" and 30" inches? I would suggest not for the most of the world, and what we have now in terms of resolution and AA is just fine. But that damn AF on a big monitor is still bothersome at best and terribly distracting and immersion breaking at worst.
 
nooh said:
Sir its a honour to talk with you in such a forum.

I have just read what you have wrote about the whole Sli setup on a 30" screen and its not one you would opt for , however if it was a quad setup and it was running smooth then would you change your mind or would you still say ATI.

I am saving up for a 30" and after what you have wrote it makes you think.

I have played Quake 4 at 1800 res and i loved it with my 7950 XXX and was quite surprised of the framerate it did too but then i read this.
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Thanks for the kind words, but I am just another guy wanting to do some gaming, I just get the cool toy a little before everyone else....or at least Brent does now.

I think it really comes down to what games you see yourself playing. If you are playing a lot of BF2 or WoW, I can see where CrossFire would be more valuable to you in delivering the best overall gaming experience. Then again Quad SLI is already working with some games even though it is not officially supported (but should be soon) and it can deliver better framerates on a 30" screen with the eye candy turned on as it has the sheer horsepower to do so.

I think if you are thinking about getting a 30" setup, just to get one, I would say hold off till things clear a bit. But if you have a specific want and need in gaming terms, read up on how it works for that/those apps then make a judgment.
 
boomheadshot45 said:
Quick question about crossfire, are they going to make intel crossfire boards when conroe comes out?
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CrossFire will work with i975 boards and Conroe with a special driver, that is not yet public to my knowledge. My GUESS would be that 965 would support it as well, but I really don't know for sure. Certainly ATI's Intel 3200 chipset will support CrossFire and Conroe...
 
I just love reading the discussions. :) I can't afford any of this, anyway.

30" LCD? I have a 15" crt, thank you.
 
Jack Hammer said:
I just love reading the discussions. :) I can't afford any of this, anyway.

30" LCD? I have a 15" crt, thank you.
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Hehe, my gaming panel is 3 years old but I do have a nice set of 7800s in SLI thanks to MSI. :) Honestly the discussion is not looking at today, but things that need to be fixed in the next two generational GPU releases.
 
Jack Hammer said:
I just love reading the discussions. :) I can't afford any of this, anyway.

30" LCD? I have a 15" crt, thank you.
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The article is good, informative and on the egde...typical [H]ard ;)

But that being said, I will cry so loud loud you can hear it all the way to the US, when I can't get a good CRT anymore.
I have imparied shigh(shortsighted) wich I fix via lenses, but my "visual perception" is 140%
(i can see a high number of fine details on objects..the very fine small stuff..or read VERY small letters on a vision test..with my lenses in)

My eyes "screams" when looking at a LCD...something bothers me about them...."pixilated" would be the wrong word here, but something about them annoys my eyes.
A CRT at 85-100Hz on the other hand dosn't do this to my eyes.

Terra - I'd take a 21" CRT over any LCD...any day...
 
Terra said:
The article is good, informative and on the egde...typical [H]ard ;)

But that being said, I will cry so loud loud you can hear it all the way to the US, when I can't get a good CRT anymore.
I have imparied shigh(shortsighted) wich I fix via lenses, but my "visual perception" is 140%
(i can see a high number of fine details on objects..the very fine small stuff..or read VERY small letters on a vision test..with my lenses in)

My eyes "screams" when looking at a LCD...something bothers me about them...."pixilated" would be the wrong word here, but something about them annoys my eyes.
A CRT at 85-100Hz on the other hand dosn't do this to my eyes.

Terra - I'd take a 21" CRT over any LCD...any day...
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wow I feel for you. I went from 14' CRT to 15' CRT to 15' LCD and now to 17' LCD. I can tell you that my eyes would hurt over extended time (more than 3 hours) on a CRT but not on a LCD. I can do 48 hours of gaming on LCD without having eye pain as oppose to 3 hours on CRT.

The only drawback I see in 30' LCD is that it didn't have color correction onscreen. I like having 7500K color temperature, 100 brightness and 50 contrast. But its not like I have the money to get one anyways.
 
Stick some rubber feet on a removable motherboard tray, you get card support and you don't have to worry about damaging pretty cards or coppery heatsinks. It doesn't take up any more space then the motherboard really and it doesn't slow you down swapping out parts. I've been using the same two trays stolen from old foxconn cases for better then 6 years.
 
Not only does launching have a long delay but so does changing 3D options
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It might take a bit of time to launch but ive yet to see 3d options taking any amount of time to change, you do know btw you can DISABLE the 3d preview which mean the little demo graphics wont have to load and changing the options is instant right? Even with them on ive yet to encounter the options taking their time changing so i really have no clue what this part of the article is going on about. Possibly crossfire take a bit of time to enable\disable (as stated), i dunno since ive only 1 x1900xtx.
 
I dont have to reboot windows when I enable/disable SLI. Maybe you should use driver cleaner Kyle. Its been real time saver, especially with tweedling with graphic what-sa-ma-hu-sits in BF2 and other non-sli-profile games
 
Couple of things.
That article was excellent. I dont know anything about ATI. Now I do. I wouldnt give up my SLI for anything , but it seems there are really good points on both sides of the aisle.
Great sharing your experience with us.

Second.....your friends at FrozenCPU have a really nice test bench set-up that I use when Im fooling around with pieces-parts.....you'll never have to use the MB carton again, and you can quickly change out parts. Cost 75 bucks, time savings.....priceless.

Last and third......I bit the bullet and got a 2405.....man games are outrageous. I cant imagine what a 30 inch deal would be like.

Thanks again.
 
scout007 said:
wow I feel for you
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No need to?
My eyes (I remember to blink and water my eyes, my lenses warns me if I don't, they begin to dry ;) ) are doing just fine with CRT's
It's LCD's they can't stand ;)

Terra...
 
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