 So this is going to be a quick follow-up video to my GTX 660 Ti content. Now you can see here I've got two 660 Ti's running. I've got the MSI 660 Ti Power Edition as well as Galaxy's custom cooled GC card. Now for those of you who don't know, yes, you can mix vendors in SLI. Yes, you can mix different clock speeds in SLI, different PCBs in SLI. I mean this one's even running two 6-pin powers and this one's running a 6 and an 8. Different coolers in SLI. The thing that's important is that the GPU is the same, so that means you have to have a 660 Ti and a 660 Ti. No 660 Ti and a, you know, 670 or anything like that. No flexibility on the Nvidia side. Unlike the AMD side where you can run at 6990 with a 6970 and TriFire, this doesn't work that way. So just because a 690 has the same GPU as... not that. I think there's a 680 around here somewhere, but I'm not going to worry too much about it. Ah, there it is. Right, it's hiding. As a 680, that doesn't mean you can run them in SLI. Got to be matching GPUs. Also, it's been suggested to me in the past that mismatched RAM configurations are okay, but I haven't tried it in a long time and the last time I tried it, it didn't work. So there you go. Alright, so we are going to be doing like a value analysis because people ask me about this all the time. Should I buy one powerful card or should I buy two less powerful cards and run them in SLI? So there are some trade-offs right off the bat. Two cards is going to use more power, period. It's going to be noisier, period, because you got more fans. In this case, you got four fans versus one, but which isn't to say necessarily that two of these fans is louder than one of these fans, but... Well, whatever. Moving on. So yes, power, noise, both worse. Heat is worse for having multiple cards, and in 90% of cases, multiple cards is bad. Never run two of these instead of one more powerful one. That is a low-end card. Well, it's a gaming card, but it's a low-end gaming card, and you're definitely better off getting something in the sort of more bang for the buck, $250 to $350 range. That's where you usually find the best value. So we're going to take two 660 Ti's versus a single 680 and find out what delivers the best performance and the best value. So here's my first graph. This is Crysis II 1080p. I'm using all my standard settings, so this is like ubered out with high-res textures and all that good stuff. So you can see the 660 Ti configuration actually, well, destroys the 680. However, it is more expensive. It's about 20% more expensive, and when we actually go ahead and look at the performance differential, it looks like the 660 Ti comes ahead, so it's about 26% faster and 20% more expensive. And at minimum FPS, if you measure minimum FPS, it's about 20% faster there as well. So let's go ahead and you know what? I'll do the graphs off camera. Battlefield 3 again was running at uber settings, 1080p, and you can see the 660 Ti again just destroys it in terms of average FPS, but the minimum FPS was a little bit closer, so it doesn't look like as compelling a value as it at first appears when you look at the averages. However, that still does show that the 660 Ti does present a better, or SLI does present a better value than a single 680 in this particular title, as long as you're willing to make those trade-offs in terms of power consumption as well as noise. Again, running a game at 1080p with ultra-high details, and again, we see at that minimum FPS level a 20% improvement from the 660 Ti SLI config over the 680. We see about a 47% improvement in average FPS, but it almost looks like Nvidia knew what they were doing when they were pricing out a single GTX 680 versus 660 Ti SLI because they're delivering pretty much the performance that you'd expect for the dual GPU configuration versus the single one. You know what, here I'll just do this last one on... Okay, no, I won't do this on camera, I need two hands. And there's Metro 2033 where we actually see about a 30% improvement in both minimum and average FPS, so this is the clear winner. So what's neat about this cross-section of games is that these are all, well, they're all shooters, they're all demanding, Witcher 2 isn't a shooter, actually, they're all demanding and they all demonstrate that the 660 Ti not only scales consistently in SLI, but presents a compelling value versus buying a single higher-end GPU. That is to say, that's not to say though, that it's necessarily the better option because two of these is 600 bucks, one of these is 500 bucks, and for that 20% improvement, you are trading off extra heat and extra power consumption, so it's up to you. Personally, I think SLI cards look more bling-bling, and yeah, I think that's probably all else that it's got going for it, but remember, guys, when you're trying to figure out if a dual GPU configuration makes sense, you just want to look at performance per dollar. That's pretty much the only factor here because they've now got the same features, they both support 3 plus 1 videos out, even when you add another card, if you're running an SLI, you can only plug in 3 plus 1 in SLI, and this one also supports 3 plus 1 off of a single card. You also want to remember that things like memory configurations are important, so when you're running two cards in SLI, two 2-gig cards does not equal 4 gigs of video memory, okay? So they both have to share the frame buffer, which means that you still only get effectively 2 gigs, so bear that in mind as well. So I know this really didn't have a clear-cut conclusion because basically performance per dollar, they're very, very similar. This comes down to do you want a little bit more performance, or do you not want a little bit more performance? Thanks for checking out this episode of Linus Tech Tips, and don't forget to subscribe. For more unboxings, reviews, and other computer videos.