x4 pcie crossfire

[NicholasNicholasNicholas]

im just wondering if a x4 pcie gen 3 will bottleneck 2 480s in crossfire. i dont want any performance loss and im willing to spend more on a mobo with x8 on 2. my cpu is a 6402p which only has 16 pcie slots so x16 on both is out of the option. but will one in x4 and one in x8 reduce performance? i think x4=x16gen 1

[The Sloth]

x8 will be better, try to get a mobo with 8x. 

[ARikozuM]

Even though the bandwidth would be greatly reduced, I don't want to say that it wouldn't matter as it may actually affect the performance.

 

Edit: Pay for the x8 slots.

[NicholasNicholasNicholas]

Just now, Andydandyfiddy said:

Why would you want to go for 2x RX 480? If the answer is for future proofing then sure, But if not you should go for a GTX 1080. Or Maybe AMD Vega whenever the hell it's going to come out.

 

already have them. and this is the problem with forums... instead of being helpful everyone just questions you

[79wjd]

x4 won't bottleneck you, but your CPU might depending on the games you play and the resolution you play at. 

[NicholasNicholasNicholas]

Just now, djdwosk97 said:

x4 won't bottleneck you, but your CPU might depending on the games you play and the resolution you play at. 

ok, thanks. 
my cpu already does bottleneck me in a lot of games too

[xAcid9]

I don't recommend doing that, the 4x PCIE is connected to the Southbridge instead of Northbridge. Not only you get reduced bandwidth but the latency will be higher because of extra hops/overhead. You might end up with poor frame pacing.

 

Try to get a proper 8x 8x mainboard if you really want to try CFX/SLI.

[xAcid9]

4 minutes ago, Nickathom said:

ok, thanks. 
my cpu already does bottleneck me in a lot of games too

Then there is no reason to OC your GPU if you already CPU bottlenecked in games.

[Princess Luna]

While a better motherboard would ensure full potential of the CF is taken, doing CF on 4x would still prove significant higher performance over a single card, ahem... considering support of course.

 

With that said, it goes pretty much as in; are you willing to pay for it's full potential or half way through's good enough? ^^

[NicholasNicholasNicholas]

Just now, xAcid9 said:

Then there is no reason to OC your GPU if you already CPU bottlenecked in games.

i already have 2 480s and a mobo upgrade is cheaper than getting a 7700

[xAcid9]

2 minutes ago, Nickathom said:

i already have 2 480s and a mobo upgrade is cheaper than getting a 7700

That's fine but don't expect smooth experience with CFX when your proc already bottlenecked a single 480.

[NicholasNicholasNicholas]

Just now, xAcid9 said:

That's fine but don't expect smooth experience with CFX when your proc already bottlenecked a single 480.

i mean it only bn me in some games like gta and andromeda

[xAcid9]

1 hour ago, Nickathom said:

i mean it only bn me in some games like gta and andromeda

Well, worse case you can just VSR to 1800p/2160p to make it more GPU bottleneck with CFX

[NicholasNicholasNicholas]

Just now, xAcid9 said:

Well, worse case you can just VSR to 1800p/2160p to make it more GPU bottleneck with CFX

4k is a bit high for dual 480s, i think ill do it with 1440p

[xAcid9]

1800p is the sweet spot if you get good scaling i think, my old 290x perform really nice at that res.

[NicholasNicholasNicholas]

Just now, xAcid9 said:

1800p is the sweet spot if you get good scaling i think, my old 290x perform really nice at that res.

how do you get 800p?

[xAcid9]

1 hour ago, Nickathom said:

how do you get 800p?

1800p. Is it not available for RX-480?

 

GCN 1.1(290/390 series) VSR is limited to 1800p max while newer GCN can get 2160p(4K). I don't know if 1800p resolution is available or not for those newer cards.