SLI question

I’ve currently got 1 GTX 970 and I’m looking at adding another one. I’ve got an EVGA FTW edition currently and it’s OC’d as much as I possible could with just a slight gain in voltage. My question is when I go to add another GTX 970 will they (similiar to RAM) only work as hard as the weakest link with SLI or does it matter? So do I need to look for another GPU that I can get clocked as high as my EVGA or can I be less picky? I’m definitely only going to consider the MSI variant or the EVGA variants, because by reviews that I actually trust the MSI seems to be the front runner and EVGA has never done me wrong. The only other brand I would probably consider would be Gigabyte, but their ASIC quality leaves some to be desired with the 970s, and I’m on air so…

Also my motherboard with 2 cards will only be able to push 8x on the PCI slots. Is that going to matter?

I’m pretty familiar with hardware itself, but this is the first time I’ve ever done SLI so I’m not 100% familiar with the ins and outs.

Thanks in advance.

What resolution screen(s) are you trying to push?

At the moment 1080, later I’d like to move into the 1440 realm. 2160 is really not of interest to me, because the cost to get into it is just too high and I don’t see that changing much for at least the next 3 years.

Only 1 screen as far as gaming goes.

Is this for Star Citizen, or some other game running too slow right now? In theory a 970 should run games @ 50+ fps on a 2k monitor.

It’s really just to level off newer titles to run at a solid 60 FPS no matter the settings. I’m getting the 50 mark now, but in more intensive titles like the Witcher 3 it’s 50 FPS with some tweaks to AA and/or post processing effects.

It’s not really for Star Citizen in particular, just for modern titles in general.

Cool, you should see a 60-70% performance bump in games that can take advantage of SLI.

Hi Lema,

i would not say you need another GTX 970 at all. just bring ist to higher clock levels and turn off some quality settings to reach the 60 FPS mark. The 970 has ohnle 3,5+0,5 GB RAM - this is really a problem in SLI configurations. Once your VRAM is full you will get stutter. Maybe in most games SLI will work out quite well. But in games like SC it will simply be limited by the amount of VRAM once you bump up the quality settings.

Back to your questions…
“So do I need to look for another GPU that I can get clocked as high as my EVGA or can I be less picky?”

  1. You need an SLI certified Board (i guess you know this, just saying)
  2. You don’t need to look for same GPU - but you need one with an identical chip and VRAM amount - this matches any GTX 970 today.
  3. BUT… you need to carefully look at the PCB size of the 2nd GPU. If you don’t have an flexible SLI-Bridge, it won’t fit in case the PCB is larger or smaller.
  4. The SLI configuration will work on the highest clock levels both cards can run. This means the slower one limits the faster.
    But you can simply ajust the clock levels by using MSI Afterburner or the EVGA Tool.

“Also my motherboard with 2 cards will only be able to push 8x on the PCI slots. Is that going to matter?”
No, it will not. I guess you have an 1150 socket board?
PCIe 2.0 x8 has still enough bandwith for GTX 970 cards. PCIe 3.0 is even better, having twice the bandwith.
If you want to go for 2x PCIe x16 , you will need an x99 Board with an i7-5930K or even better.

SLI works quite good today. But i dont think two GTX 970 are worth ist in the long term.
You always have to aim for the double frame buffer.

Best thing you can do right now ist this: buy an monitor with G-Sync.
This will help you a lot more then a second GPU and it will save you lots of troubles.