4-Way Crossfire/SLI Support

L3gendary_Gam3r · Apr 14, 2015

Hey guys, I'm building my 1st gaming PC and have a little question about PCI lanes and 4-way graphics cards.

The motherboard I chose (ASRock Z97 Extreme9) supports 4-way with 40 PCI lanes with a PLX PEX 8747 Bridge but my chosen CPU (Intel Core i7 4790K) only has 16 PCI lanes.

Will I still be able to use 4-Way Crossfire/SLI at x8/x8/x8/x8?

blue_smoke · Apr 14, 2015

Don't even think about 4 way sli or crossfire. You shouldn't go past two cards, it's hard to see any benefit past 3 cards.

ko888 · Apr 14, 2015

L3gendary_Gam3r :

Yes. That's the whole point of the PLX PEX 8747 multiplexing switch chip.

Bossyfins · Apr 14, 2015

KO888 perfectly explains this. The PLX PEXchip is like a repeater. It allows for more lanes.

L3gendary_Gam3r · Apr 14, 2015

blue_smoke :

Thanks, I'll keep that in mind. Just wanted to future-proof but you're right, 3-way is as far as I'll go. I think I'l save a slot for a sound card or a PCI SSD

-Lone- · Apr 14, 2015

You should just stick with 2, what resolution and settings are you gonna play on? What GPUs are you planning to get for it?

L3gendary_Gam3r · Apr 17, 2015

-Lone- :

As soon as I get a monitor that supports it, 4K. As for the settings everything must be maxed out. Maybe the R9 290X, I'm not sure yet, which one do you recommend? At a price range between $150-350

Bossyfins · Apr 17, 2015

350$ max for 4k isnt enough. the 290x doesnt work well as a single card soultion to 4k. An SLI./CF system is needed.

L3gendary_Gam3r · Apr 17, 2015

Bossyfins :

Yeah I'll CF 2 of them (max 3), that's gotta be enough, right?

-Lone- · Apr 17, 2015

L3gendary_Gam3r :

If you want max everything and close to 60 fps "without" stutter/fps drops for new games, you'll need anything beyond a Titan X, such as 980 ti or 390x or the Titan X itself. Current GPUs are no longer an option for 4k ultra for new games because lack of VRAM. Some current games such as FC4, BF4, DA: Inquisition already uses up to 5GB and 4.5GB on average on ultra. The newest game such as GTA V uses up to 6.8GB of VRAM on ultra in some places and moments but uses an average of 5GB 95% of the time while playing. But even 1 Titan X OC'ed is not enough for ultra everything in "some" places like mountains, deserts, just places with a lot of grass or something, only an average of 30 fps in those areas for GTA V, so if you want 60 fps, you'll need 2 Titan X in SLI, but most of the time it gets around 45 fps with 1 Titan X. So if you wanna get cheaper GPUs as strong as the Titan X with higher VRAM, you should wait for the 390x or 980 ti. Without the extra VRAM, the game will stutter and have fps drops, I don't think you'd want those while playing.

Bossyfins · Apr 17, 2015

I;d wait on the new 3xx series from AMD. MAJOR power change in 290x for about 2 290xs. ALso comes with 6-8 gigs of gddr5. It should be released soon

L3gendary_Gam3r · Apr 19, 2015

-Lone- :

Bossyfins :

Yeah, good idea. I did some research myself and decided to wait. Thanks

L3gendary_Gam3r · Apr 19, 2015

-Lone- :

L3gendary_Gam3r :

If you want max everything and close to 60 fps "without" stutter/fps drops for new games, you'll need anything beyond a Titan X, such as 980 ti or 390x or the Titan X itself. Current GPUs are no longer an option for 4k ultra for new games because lack of VRAM. Some current games such as FC4, BF4, DA: Inquisition already uses up to 5GB and 4.5GB on average on ultra. The newest game such as GTA V uses up to 6.8GB of VRAM on ultra in some places and moments but uses an average of 5GB 95% of the time while playing. But even 1 Titan X OC'ed is not enough for ultra everything in "some" places like mountains, deserts, just places with a lot of grass or something, only an average of 30 fps in those areas for GTA V, so if you want 60 fps, you'll need 2 Titan X in SLI, but most of the time it gets around 45 fps with 1 Titan X. So if you wanna get cheaper GPUs as strong as the Titan X with higher VRAM, you should wait for the 390x or 980 ti. Without the extra VRAM, the game will stutter and have fps drops, I don't think you'd want those while playing.

Yeah ur right, I checked some benchmarks and 2-way 290X crossfire can only achieve 30-45 fps on 4K ultra. I'll wait for the next AMD 300 series. How much do you think they're gonna cost?

-Lone- · Apr 19, 2015

My guess is $650 on average, more or less.

L3gendary_Gam3r · Apr 20, 2015

-Lone- :

Ouch, I'm gonna stick with 2x 290X, and just play at 1440p at 60 fps

Bossyfins · Apr 20, 2015

But it might be better. From what the rumors are, its about 40% faster than the 980. SO it would be the speed of 2 290x with about 8 gigs of vram on board

L3gendary_Gam3r · Apr 21, 2015

Bossyfins :

You have a point, I'll think about it. Besides I'm only buying the GPU's in late 2015, by then the prices might have dropped. Thanks for ur help!

4-Way Crossfire/SLI Support

Reputable

Honorable

Titan

Splendid

Reputable

Admirable

Reputable

Splendid

Reputable

Admirable

Splendid

Reputable

Reputable

Admirable

Reputable

Splendid

Reputable

Share this page