
Are two RX 480s faster than a single GTX 1080? - doener
http://arstechnica.co.uk/gadgets/2016/07/amd-rx-480-crossfire-vs-nvidia-gtx-1080-ashes/
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valarauca1
The real TL;DR is no. They are about equal.

Ashes of the Singularity is a game AMD had a big hand in making. There are
driver level optimizations the studio paid for. Furthermore the game leverages
D3D12's Async Compute which Pascal Architecture can't handle as well as GCN.

That being said in non-AMD sponsored games they two set ups in question (RX480
CFire vs GTX1080) do manage to stay within step of one another [1].

The real issue becomes overclocking and crossfire.

The GTX1080 has a much higher overclock threshold then RX480 (currently this
may change as board partners make custome PCB's). So if you start fiddling
with power levels this comparison breaks down.

Also crossfire/SLI is to a degree Russian Roulette. Studio's have to opt-in to
supporting it, and sometimes don't. Leaving you only with a single card. Also
very weird bugs can sometimes crop up. Some people have no issue with this,
some have huge issues. YMMV.

The main thing I'm trying to express is when looking into hardware reviews
CPU/GPU's more information from more sources is always better. And all
sources/chips aren't equal.

[1] [https://youtu.be/cVVJPbFRDEc](https://youtu.be/cVVJPbFRDEc)

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rdudek
Async Compute is a big mess for nVidia right now. Latest trouble is Total War:
Warhammer game. They released dx12 support for it and nVidia cards are losing
10fps+ while AMD cards are gaining 30%+ in performance. Also reason why Ark
Survival Evolved is holding off dx12 release because of nVidia ...

~~~
jsheard
It's really difficult to draw conclusions from DX12 benchmarks at the moment.

The problem is that DX12 shifts most of the responsibility for architecture-
specific optimizations (and avoiding pathological cases) from the driver to
the application. So although you _could_ draw the conclusion that Nvidia are
struggling with DX12 due to their Total Warhammer performance, it's just as
easily explained by Nvidias veteran DX11 driver team being better at tuning
for Nvidia hardware than a game studio who partnered with AMD during
development.

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tarpherder
I would never consider a multi-GPU setup. I know from first hand that support
on those setups ranges from pretty good to non-existent, but it is an area
that receives only little attention once the initial multi-GPU launch is done
(if there even is multi-GPU support). So future patches etc may introduce
instability for those setups (and they are often unstable at launch with quite
a few issues) and only luck or a driver update (1-2 months) will fix it.

Additionally, with ever increasing resolutions and complex rendering pipelines
that need an increasing number of syncs between the individual GPUs; SLI and
CrossFire bridges are becoming more and more of a bottleneck.

Would not recommend.

~~~
emdd
Why do you think they are so poorly supported? I know relatively few users
have multi-GPU systems...it may be as simple as that, but I would have
expected DX, OpenGL, and the new one from Valve (blanking right now, Vulcan?)
would have improved usage and stability with minimal per-game development.

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jsheard
TechPowerUp tested it more thoroughly than Ars:
[https://www.techpowerup.com/reviews/AMD/RX_480_CrossFire/](https://www.techpowerup.com/reviews/AMD/RX_480_CrossFire/)

In short: even if you exclude games that don't utilize multiple GPUs, a pair
of RX 480s is slower than a GTX 1080 on average.

If you do include non-scaling games they're slower than a GTX 1070 on average,
which is cheaper than the 480s and uses half the power.

~~~
STRML
So the 1070 is the no-brainer choice in this price range. A single card is
always better than XFire/SLI, and you have the option to move to 2x1070s if
you need the boost. SLI scaling on the 10xx series has been really impressive.

~~~
StavrosK
Is that a good card? I saw an article linked somewhere from this post that I
can't find now, but it said that things are about to get very good for
graphics card purchases. I'm not sure if the article was old and things have
gotten better.

I'm basically wondering what I should replace my current card with (I run
Linux and play a few games like rocket league).

~~~
PascLeRasc
You can get used 970s for about $200 now

~~~
speeder
You can get new 970 for slightly more than that... I regret buying a 380x
instead.

AMD drivers have serious bugs (that also affect the 480!) that they promised
to fix a year ago, but not only they didn't fixed it, they also removed it
from the "known issues" list on the changelogs. This was my first AMD purchase
and will be my last, their hardware is mediocre (super power hungry and
throttles because of that), software is outright terrible, and support from
both them and Sapphire is nonexistent.

And when I asked for help on forums and chats, people accused me of being
nvidia paid troll and even banned me. (And someone later pointed out to me
that the places that most aggressively attacked me are the ones that have AMD
employees as moderators)

~~~
eropple
_> their hardware is mediocre_

It also seems like RX 480s also overdraw the PCIe bus (drawing more than 75W
from the slot--cards are supposed to be able to pull 75W from the slot, 75W
from the six-pin connector, and 150W from the eight-pin connector), which is
potentially dangerous for the _rest_ of your hardware, too.

I went from being a steady AMD/ATI customer (last card was an HD4870) to a
980Ti and don't see myself going back anytime soon.

~~~
jsheard
More on the PCI-E slot overdraw: [http://www.pcper.com/reviews/Graphics-
Cards/Power-Consumptio...](http://www.pcper.com/reviews/Graphics-Cards/Power-
Consumption-Concerns-Radeon-RX-480)

It's concerning at stock settings but gets far worse when the card is
overclocked, with the card overloading the 12V pins by about 50%. AMD say they
are working on a driver fix at least.

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Hamcha
Considering the idea was to spend less, I'm amazed he didn't mention power
usage of having 2 cards vs 1 (best case you spend double in electricity, worst
case you actually need a better PSU)

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yellowapple
Betteridge's law of headlines strikes again, though as least Ars seems to be
self-aware about it.

