GTX 1070/RX 480 Crossfire Upgrade from R9 390X

[flamingspartan3]

I recently bought an R9 390X for effectively $270. However, I have been recently thinking of upgrading to Crossfire Rx 480s. For reference, I only play 1 game on PC, GTA V, which has good Crossfire support. I can sell my 390X and upgrade to the 480s for only a small amount of extra money.
My issue is that I'm unsure if my motherbaord supports Crossfire. I have an Asus P8Z68-V LE which advertises Crossfire support. However, it only has 1 PCIE 2.0x16 slot while the other one runs at x4 I believe. I've read in some places is that it might be possible to force both slots to run at x8.
Is it worth upgrading to the Crossfire 480s or should I just get a GTX 1070 for a similar price. Or is an upgrade not at all necessary?

My Current Specs:
Core i7 3770S
8 GB 1333 DDR3 RAM
R9 390X
850 Pro SSD
2560 x 1080 Ultrawide 29 in monitor

 

[madmatt30]

At 1080 ultrawide your 390x is surely managing absolutely fine ??

 

[flamingspartan3]

At 1080 ultrawide your 390x is surely managing absolutely fine ??

It is quite good but I am getting a decent amount of frame drops . I'm not sure if this is a CPU/RAM issue though.

 

[sizzling]

Last I heard Crossfire on GTA V was still pretty poor, not the mess it was for the months after the game launched but still not great. I'd always opt for a single stronger card.

 

[madmatt30]

^ this is true - where do you go from a 390x though which is a great GPU still for that intermediate ultrawide resolution??

The 390x should be stomping games at that res easily enough (bearing in mind I don't know of any 2560x1080 screens that run more than 75htz) at 60fps+.

 

[flamingspartan3]

^ this is true - where do you go from a 390x though which is a great GPU still for that intermediate ultrawide resolution??

The 390x should be stomping games at that res easily enough (bearing in mind I don't know of any 2560x1080 screens that run more than 75htz) at 60fps+.

It's possible that my CPU/RAM is bottlenecking it. I can overclock my CPU to 4.3 GHz and upgrade to faster RAM and see if that makes a difference. My 390X gets good average framerates; however, the minimums are somewhat low (35-40) on GTA V

 

[sizzling]

RAM speed will make negligible difference, 1 or 2 fps at the most. Your CPU at 4.3Ghz will be more than enough, it should be fine at stock. Its just a demanding game. What are your CPU any gpu usages when you get the drops to 35-40? My guess is your maxing the gpu

 

[flamingspartan3]

RAM speed will make negligible difference, 1 or 2 fps at the most. Your CPU at 4.3Ghz will be more than enough, it should be fine at stock. Its just a demanding game. What are your CPU any gpu usages when you get the drops to 35-40? My guess is your maxing the gpu

My GPU usage remains at 100 generally throughout. However, when my FPS drops, my CPU usage increases significantly as well . Since I have a 3770S, my four cores can max out only at 3.5 GHz normally. The reason I mentioned RAM speed is that it may have a larger effect on GTA V specifically.

http://www.eurogamer.net/articles/digitalfoundry-2016-is-it-finally-time-to-upgrade-your-core-i5-2500k

 

[madmatt30]

There are certain settings (if you use very high or ultra presets) that will cripple literally any gpu.

http://www.gamersnexus.net/game-bench/1909-gta-v-graphics-optimization-guide