Yeah Bitches! SLI Incoming!

[botfly10]

So...

I am about to become a sli user. I don't know shit really about SLI except that I see a lot of people seeming to **** with their setup all the time cause they have issues on various message boards.

However, I just scored a 2nd Asus GTX 780 DirectCU II from a friend for 200 bucks. Couldn't pass up the upgrade for the price. Here is the card:

http://www.newegg.com/Product/Product.aspx?Item=N82E16814121779

Anyway, now I have to figure out how to configure two gtx 780's in SLI. I know, great problem to have.

Anyone have links to a great guide or any advice? Lookin at you Crys!

I am hoping that being the same brand/model will help with some possible problems. Maybe.

 

[Crystallas]

Cool deal.

If your board supports 2 cards, PSU can drive everything steady, and you configure the cards to run in SLI with the cable. Then you're set. It's not all that complicated.

People that have issues, cut corners or have boards that aren't SLI ready for the PCIe version of the cards.

I've been running SLI/CFX + hybrids for years with very little issue. Sometimes I build a workaround, and that's the most work. As you get familiar with it, it's very easy. And if you run into issues with older games, just disable SLI for that game. nVidia has a SLI profile tool, this will allow you to slip your settings straight away for each executable, and this is also where most people have issues setting up configs. Once you go multi-card, or SMP, you need to tinker. 50% of games are install and go, the other 50% requires a profile or config edit.

 

[botfly10]

Awesome, thats great news. My board is SLI ready, so should be all set. **** yeah! Of course, now I find myself looking at 144Hz g-sync monitors...

 

[Unannounced Fart]

My build from 3 years ago is SLI, and all I did was put in both cards and connect 1 cable between the 2 cards. That's it, simple.


Sent from my iPhone using Tapatalk

 

[botfly10]

**** yeah, I'm psyched. Two 780's is pretty outta control.

Hey Crys, do you have any experience with the closed system liquid CPU cooler things? Like the CORSAIR Hydro Series H100i?

I use a big ass Noctua air cooler right now which works fine and I love for simplicity. But it doesn't vent directly out of the box like those liquid coolers. Just blows air across fins without really venting to the outside. I was thinking with the increased heat from a 2nd GPU that it might be smart to get one of those liquid coolers to maybe keep the overall ambient temp inside the box down.

Only thing is I read horror stories of the hose fittings coming loose or breaking and dumping coolant in the case...

 

[Crystallas]

Yeah, I've done things with every cooling system you can think of. Mineral Oil, CO2, LN2, water, pelts, and obviously, air.

Only tip I have, is buy legit coolant, the stuff that doesn't corrode the metals/epoxies over time, and it also doesn't conduct electricity if/when you have a small or big leak. I've built dozens of liquid cooled systems, and all it takes is just one leak of conductive liquid to render a very expensive rig useless.

Obviously, if you go liquid cooled, you're going to plan around it. Buy a case that supports the tubing and radiator space. Consider mounting your rear fan externally with a fan grille on top if you need space. Little fixes like that can retrofit different cases. Also, do a quick thermal flow breakdown in your head, try to pinpoint cool to warm airflow patterns. You'll get away with air cooling just fine as long as you remember not to obstruct airflow.

I also use the nocturnas. They're hard to beat. But if anyone needs to save a buck, that is also easy to do, as the market is saturated with excellent fans for much less that are close in all fields. Not like 2010, where Nocturna and Silverstone were in a league of their own. Also Sanyo denki is also the best fan you can buy, but these are not fans for casual builders, they do require tuning(at bare minimum, a pot or controller), you can get the same dB noise level as the top quiet airmovers, and more CFM.


I like air better than liquid, because liquid is an endless investment. But I did my first liquid cooled system with a Cyrix 686 and a Celeron 350 shortly after. It's like a midlife crisis when you need to buy that sports car. Everyone that likes to build all of their systems will liquid cool at least once in their life(usually never again). My last liquid cooled system was in june, because I had a client that needed to quadfire 295x2 cards(they work with construction CAD modeling, and this was faster/cheaper than buying workstation cards/quadros). The radiators are okay on the cards, but I used a transmission cooler with a pair of 240mm fans to cool the loop for the cards and CPU. It works brilliantly for what it is. Screaming fast system and still overclocks.

 

[botfly10]

Yeah I have been doing some reading up. I had this idea that CPU air coolers kinda just blow air around that is already in the case. And a closed loop water cooler vents more directly to the outside. But after reading, I think I was overestimating the temp of the ambient air inside the case. I was thinking a closed loop might exhaust the case better, but after reading more, it doesn't really seem like that is true. I think I'm just going to leave the Noctua and add another exhaust fan wherever I can fit it along with another fan internally that blows across both GPU cards.

 

[Mitchapalooza]

GPUs are definitely the #1 computer part that people buy yet never need the power for. I'm guilty as well. When I build my PCs I buy a GPU that I'll never fucking need

 

[Ares]

GPUs are definitely the #1 computer part that people buy yet never need the power for. I'm guilty as well. When I build my PCs I buy a GPU that I'll never fucking need

I gotta disagree here.... for gaming its the most important thing you buy and games will always outpace your GPU eventually.... so no matter what GPU you buy you will eventually need a better one.

I would say memory is the thing people tend to over-do for no reason... "Bro I put like 64GB of RAM in my new build".... cool do you plan to do anything that uses lots of memory? SQL Server? Video editing/processing? "Nah bro just gonna play Call of Duty and WoW".... mkay you don't need 64GB of RAM for that, but enjoy.

 

[botfly10]

What Ares said. I max out my GPU all the time. And 2 780's is dumb for 1080 but not if I go 1440 or 4k. Not to mention 144Hz.

If you are a gamer, the GPU is the most important component.

 

[Crystallas]

Yeah I have been doing some reading up. I had this idea that CPU air coolers kinda just blow air around that is already in the case. And a closed loop water cooler vents more directly to the outside. But after reading, I think I was overestimating the temp of the ambient air inside the case. I was thinking a closed loop might exhaust the case better, but after reading more, it doesn't really seem like that is true. I think I'm just going to leave the Noctua and add another exhaust fan wherever I can fit it along with another fan internally that blows across both GPU cards.

Depending on your thermal flow, slot fans can also do wonders for the ambient temps.

 

[botfly10]

Interesting you mention that cause I just heard of those. That might do the trick for me. Especially if I can get it between my GPUs so it vents the lower one outside.

 

[Crystallas]

Interesting you mention that cause I just heard of those. That might do the trick for me. Especially if I can get it between my GPUs so it vents the lower one outside.

Just make sure you get it facing the right direction, and the one you buy doesn't block the GPU coolers. But yeah, I love blowers/slot coolers. I'll use them for all kinds of electronics, not just PCs. They aren't as good as standard fans, but space constraints will kind of make that decision for you. As well as the handy method of zip-tying a fan on top of the GPUs, this is also effective(especially if you have vents on your case's side panel).

 

[botfly10]

You are giving me all kinds of ideas.

 

[Crystallas]

You are giving me all kinds of ideas.

That's what you wanted, right?

 

[Mitchapalooza]

I gotta disagree here.... for gaming its the most important thing you buy and games will always outpace your GPU eventually.... so no matter what GPU you buy you will eventually need a better one.

I would say memory is the thing people tend to over-do for no reason... "Bro I put like 64GB of RAM in my new build".... cool do you plan to do anything that uses lots of memory? SQL Server? Video editing/processing? "Nah bro just gonna play Call of Duty and WoW".... mkay you don't need 64GB of RAM for that, but enjoy.

Yeah but I never play crazy demanding games. Maybe it's just me then.

 

[botfly10]

Yeah, once my 2nd card gets here, I am gonna look into zip tying a fan in so it blows between the 2 cards.

I really dont want to put a fan on the top or side of the case, so I might need to do an external exhaust fan as well.

 

[Crystallas]

No no, you don't want to blow between the cards. You want to exhaust the hot air away from the cards.

Lemme drop some MS paint.


View attachment 1916


The further you have the fans apart, the less turbulence you create with your primary flowzone(which is the front case fan, and the rear(multiply by however many you have). Then the secondary flowzone, the other axis, here I just labeled it as UP. Because that pulls hot air away from the board itself and creates more cool airflow from the intake fans in the front of the case.

 

[botfly10]

I have been busy as shit lately, but once I get box set up, I will post a picture for some mode ideas.

 

[botfly10]

Here is what I have so far:

There is a fan on the top that you can't see. The yellow square is a fan mounted to the side of the case that is blowing air from the outside onto the cards. I set it up this way because I was a little nervous about starving them of air.

Also, pardon my cable management. Closed case, so I don't care that much about how they look, not enough to spend excessive time or money, as long as they are somewhat neat and not blocking airflow.

Here is the case I have:

With side panel off:

Top panel opened up: