Questions on SLI

[BoinkVX]

I don't know a lot about how SLI works exactly, but I'm considering getting another GPU as an upgrade for my rig. So before I decide anything for sure and spend a lot of money on something that may not be what I expect I have a few questions.

Here are my specs:
Intel Core i5 4670K @ 3.40GHz
16.0GB Dual-Channel DDR3
MSI Z87-G45 GAMING
2047MB NVIDIA GeForce GTX 770
238GB Samsung SSD 840 PRO Series ATA Device
931GB Western Digital WDC WD1002FAEX-00Y9A0 ATA Device

1. Is it better to use SLI or have a single GPU that's more powerful?

2. How much exactly would SLI increase power consumption? I feel like that's pretty obvious but I'm wondering if the extra cards use full power all the time considering they aren't always used.

3. How compatible are different cards with each other? I know I can't mix NVIDIA and AMD but I don't know if I have to use the same kind of card and manufacturer or not.

4. Is SLI really worth it for my rig? Honestly I'm looking at it mostly so I can play games with max Physx at 60fps.

 

[runo]

1. Always try to get a single more powerful GPU where possible. SLI is beneficial if you've got an older card that you can double up on and it rounds up to more/as powerful as and/or cheaper than buying a new beefy card.

2. SLI doesn't double power consumption directly, but it will add to the workload your PSU is dealing with. If you can name the make/model and the wattage of your current PSU, that'd help us figure out if you can safely SLI, though see #4 for an addendum.

3. It has to be the EXACT same card. You can't SLI a GTX 670 2GB with a GTX 670 4GB for example. It's got to be the exact card right down to the serial number of the model that you'd find on say, NewEgg or Amazon (or the back of the box if you're in a local store). I don't mean the retail serial code, but the actual model number/serial.

4. For your rig, in my honest opinion: No -- the GTX 770 is a very powerful card. My GTX 670 STILL runs all the games I throw at it on Ultra/Maxed @ 1080p, to the point where I can actually run two such games at the same time without a hint of lag. The 770 is an even more powerful GPU so you should be set for at least a couple years.

 

[BoinkVX]

My PSU is a M12II-620Bronze, 620W

Thanks for the reply, now that I know for sure that I have to get another 770 this probably isn't going to happen for a while.

 

[Wizekraker]

whats wrong with your 770?

 

[Snipeye]

This website will help: http://www.geforce.com/hardware/technology/sli/faq#c16

To go with runo:
Can I mix and match graphics cards that have different GPUs?
No. For example, an XXXGT cannot be paired with a XXXGTX in an SLI configuration.

Can I mix and match graphics cards from different manufacturers?
Using 180 or later graphics drivers, NVIDIA graphics cards from different manufacturers can be used together in an SLI configuration. For example, a GeForce XXXGT from manufacturer ABC can be matched with a GeForce XXXGT from manufacturer XYZ.

The important thing to understand that you can mix and match any video card, so long as they're based on the same chipset/architecture. If they're different, then you cannot SLI them. When you want to SLI, just be sure to do your homework; verify they're on the same architecture, cores, etc. Now Crossfire, that's a different thing to know...

 

[BoinkVX]

whats wrong with your 770?

Nothing, I only drop below 60 fps on poorly optimized games and games with Physx like Batman Arkam Asylum or Borderlands 2, even then under certain circumstances. This is now mostly for educational purposes, since I may go SLI in the years to come for a new rig or to upgrade my current one.