Do AMD FX CPUs Bottleneck Fast GPUs?

MrN1ce9uy · Dec 5, 2016

How can an FX-6100 (or similar AMD) bottleneck a GTX 1060 without using 100% of the CPU? (Asking for a friend.)

It's difficult to understand how the GPU is held back by a CPU that isn't being utilized 100%.

His system:

FX-6100
970 mobo (he can OC, not sure how much)
8GB DDR3 1600
EVGA GTX 1060 3GB FTW+
? 550W PSU

Playing Fallout 4 at 1080p on max settings he said his GPU usage was around 60-70%, while also his CPU usage never reached 100%.

Moleg1 · Dec 5, 2016

MrN1ce9uy :

the 6100 will "bottleneck" the 1060. But only in cpu intensive games like bf1, gta v, etc. other games that are more graphically demanding should run "alright". As for all your percents. If the game is utilizing 93% lets say, and the gpu is at 60% then it is still holding back the gpu since that other 7% may be reserved for somethign in the background, or even a game overlay.

Ecky · Dec 5, 2016

Easy: If a game can only use 2 cores and it maxes those out, you'll only see 33% utilization. The game will be CPU bottlenecked even though 2/3 of the CPU is sitting idle.

MrN1ce9uy · Dec 5, 2016

Thanks.

I'll get him to use Afterburner to see each cores utilization.

geofelt · Dec 5, 2016

Depends on the game.
Many games are essentially single threaded.
Windows will distribute the activity of a fully loaded single thread over all available threads. Thus on a 6 core you might see something like 15-% utilization.
FX cores are slow, not what a gamer wants.

junkeymonkey · Dec 5, 2016

Core i7 4770K vs AMD FX-8350

Read more: http://www.tweaktown.com/tweakipedia/58/core-i7-4770k-vs-amd-fx-8350-with-gtx-980-vs-gtx-780-sli-at-4k/index.html

like geofelt said depends on the game / program maybe balanced ? maybe more CPU bound then maybe GPU bound ?

In the end with out a doubt intel has more processing power pre core then amd cpu ever will . intel is just way faster

Processor(s): Intel(R) Core(TM) i5-4670 CPU @ 3.40GHz
> Computation Time: 174.334 seconds
> Total Time: 182.220 seconds
> CPU Utilization: 385.460 %
> Multi-core Efficiency: 96.365 %

Processor(s): AMD FX(tm)-9590 Eight-Core Processor
Logical Cores: 8
Computation Time: 265.643 seconds
Total Time: 280.166 seconds

CPU Utilization: 737.512 %
Multi-core Efficiency: 92.189 %

same test on my rigs the intel ''non K' I5 was 100 seconds faster to calculate pi Decimal Digits: 1,000,000,000

maybe something from here may help as well ?

http://www.pcgamer.com/will-your-cpu-bottleneck-your-graphics-card/

and why when you see AMD cpu's being talked up its all ways ''good enough '' for gaming like ya, it will get you by

MrN1ce9uy · Dec 5, 2016

geofelt :

Interesting, I didn't know it distributed a single-threaded application like that. But it does make sense, I was just under the belief that people didn't know what they were talking about when they said most applications are single-threaded, because I've always seen them use more than one thread.

*He built his computer back in 2011 btw.

Decends · Dec 5, 2016

Programs can "use" multiple threads, but it also depends on how efficient and effective those threads are at doing their jobs. The problem with AMD CPU's is that they are designed with mainly multi-core performance over single core. Problem is that most games and programs are dependent on single core performance even when they use multiple threads which is why games like Battlefield 1 and GTA V can use multiple threads very well but a I7 with 4 cores/8 threads will leave the FX 8350 with 8 "cores"/8 threads sitting on its tail. Because the 4 cores/8 threads of the I7 do the same job far better do to better core and thread design. AMD cores for the FX 4000/6000/8000 series are really 1 core divided into 2 smaller weaker cores (FX 4100 is in sense a dual core divided into 4 for example) every 2 cores share certain resources between each other which in effect comes out to poor performance for AMD at single core tasks.

junkeymonkey · Dec 5, 2016

Processor(s): Intel(R) Core(TM) i5-4670 CPU @ 3.40GHz
> Logical Cores: 4
> Physical Memory: 16,756,445,184 bytes ( 15.6 GiB )
> CPU Frequency: 3,398,990,144 Hz
> Program Version: 0.6.7 Build 9457 (Linux - x64 AVX2 ~ Airi)
> Constant: Pi
> Algorithm: Chudnovsky Formula
> Decimal Digits: 1,000,000,000
> Hexadecimal Digits: Disabled
> Threading Mode: 4 threads
> Computation Mode: Ram Only
> Working Memory: 4,859,459,952 bytes ( 4.52 GiB )
> Logical Disk Usage: 0 bytes ( 0 bytes )
> Start Date: Wed Feb 25 03:01:59 2015
> End Date: Wed Feb 25 03:05:01 2015
> Computation Time: 174.334 seconds
> Total Time: 182.220 seconds
> CPU Utilization: 385.460 %
> Multi-core Efficiency: 96.365 %

from my post above see how a i5 Multi-core Efficiency: 96.365% don't even need a i7 don't confuse with hyperthreading but I do see where that would pay off at times [I will not do another i5 and will go xeon or i7 for now on ]

then that 4 core over that amd chip with using 8 [so called 8 ] and still a 100 sec faster

like they all ways say AMD is ''good enough '' [I guess? ]

MrN1ce9uy · Dec 5, 2016

There's no doubt we both (my friend and I) know that Intel chips are faster. It's just difficult to convince him his CPU is bottle-necking his GPU because he sees that his CPU isn't hitting 100% usage.

**Fallout 4 has vsync enabled, so maybe that's the reason why it wasn't getting high GPU usage.

Decends · Dec 5, 2016

junkeymonkey :

Processor(s): Intel(R) Core(TM) i5-4670 CPU @ 3.40GHz
> Logical Cores: 4
> Physical Memory: 16,756,445,184 bytes ( 15.6 GiB )
> CPU Frequency: 3,398,990,144 Hz
> Program Version: 0.6.7 Build 9457 (Linux - x64 AVX2 ~ Airi)
> Constant: Pi
> Algorithm: Chudnovsky Formula
> Decimal Digits: 1,000,000,000
> Hexadecimal Digits: Disabled
> Threading Mode: 4 threads
> Computation Mode: Ram Only
> Working Memory: 4,859,459,952 bytes ( 4.52 GiB )
> Logical Disk Usage: 0 bytes ( 0 bytes )
> Start Date: Wed Feb 25 03:01:59 2015
> End Date: Wed Feb 25 03:05:01 2015
> Computation Time: 174.334 seconds
> Total Time: 182.220 seconds
> CPU Utilization: 385.460 %
> Multi-core Efficiency: 96.365 %

from my post above see how a i5 Multi-core Efficiency: 96.365% don't even need a i7 don't confuse with hyperthreading but I do see where that would pay off at times [I will not do another i5 and will go xeon or i7 for now on ]

then that 4 core over that amd chip with using 8 [so called 8 ] and still a 100 sec faster

like they all ways say AMD is ''good enough '' [I guess? ]

At this point, AMD doesn't even make the "good enough" mark anymore. Especially when I3's are now out performing AMD's high end CPU's in gaming.

MrN1ce9uy · Dec 5, 2016

Here is his system, why is it not using more of the GPU or CPU?

32% GPU usage
60% CPU usage
41fps

Ultra settings 1080p.

Decends · Dec 5, 2016

MrN1ce9uy :

Fallout 4's Graphic engine is very single core bound (like most bethesda games) As a result, that is the best the engine can do with your CPU which in return is limiting the amount of information that get's sent the GPU. The Faster the CPU, the higher the GPU usage will go till either GPU usage hits 100%, CPU Usage hits 100%, Both of the previous, or till the graphic engine's limit is reached and no amount of CPU or GPU power after will increase the FPS higher.

Now if say a I5 was taking the place of the AMD CPU, the GPU and CPU usage along with the frame rate would be alot higher. I cant remember if Fallout 4 is capped at 60 FPS by the engine like skyrim is.

junkeymonkey · Dec 5, 2016

I don't know I would feel a 6100 and a 1060 is close to balanced

like said it all comes down to what the program / game is going to use you get games that are cpu intensive or games the are gpu intensive

then you got games or programd where physics come in to play and a poor cpu will hurt you

like form here where the physycs test is all CPU

I 5 4670

http://www.3dmark.com/search#/?mode=advanced&url=/proxycon/ajax/search/cpugpu/fs/P/1614/1096/500000?minScore=0&cpuName=Intel Core i5-4670&gpuName=NVIDIA GeForce GTX 1060-6GB

FX 6100
http://www.3dmark.com/search#/?mode=advanced&url=/proxycon/ajax/search/cpugpu/fs/P/1379/1096/500000?minScore=0&cpuName=AMD FX-6100 &gpuName=NVIDIA GeForce GTX 1060-6GB

same card diff chips big score difference

now open details of the top ones from each

[4670]
Graphics Score 15 136 Physics Score 7 163 Combined Score 5 479

[fx 6100]

Graphics Score 14 580 Physics Score 6 155 Combined Score 2 668

you see when the cpu and the gpu got to work together ''Combined'' it not so good

see with that the cards are the card but the CPU comes in to play

now heres the thing the intel 4670 I used is a non ''k'' so no overclocking of the CPU on it , BUT the AMD 6100 is overclocked a lot to try to equal the physics score

now drop down to a fx 6100 from the scores list and find on running at stock and see how that changes

Graphics Score 11 795 Physics Score 3 942 Combined Score 2 007

so processing power comes in to play and then how it works hand in hand with the card used

MrN1ce9uy · Dec 5, 2016

Think doing this will help Fallout 4? http://gearnuke.com/fallout-4-heres-toggle-multithreading-pc-improve-performance/

Decends · Dec 5, 2016

MrN1ce9uy :

It might help. But not by much. And you have to put in those commands each time you launch the game in the console commands.

junkeymonkey · Dec 5, 2016

may look in to core parking ?

http://www.tomshardware.com/faq/id-1939190/increase-fps-cpu-intensive-games-windows.html

I've all ways used AMD builds , but AM3+ is what drove me to intel for my first time ever in 16 years [6100- 8100 then a 8350 all sad ]

I was never satisfied and my older 939 rig and am2 did a better all around job

one thing for sure is going to intel was by no means a bad move and glad I cut my losses from fooling around with AM3+

gamerk316 · Dec 6, 2016

MrN1ce9uy :

What happens is that while games use well over 50 threads in parallel nowadays, only a handful do measurable amounts of work. Typically, you have one thread handling the main executable, and one thread that handles the primary rendering. These two threads will account for about 90% of the total program workload.

So take the case of the FX-6300. Two cores are going to be heavily worked, while the other four are going to do minimal processing. As a result, your performance is limited by how fast each INDIVIDUAL core can process its thread. And in the case of all current AMD CPUs, single-core performance is lackluster, to put it mildly.

As a result, even though the CPU may be < 33% utilized, you have a CPU bottleneck due to the poor performance of any SINGULAR CPU core.

coolcole01 · Dec 6, 2016

Here is a decent video showing a 1080 being run by a high end intel and an 8 core amd. The point of the videwo is not to say amd is garbage its to watch the readings on his screen and you will see what points the cpu starts to bring down the gpu.

https://www.youtube.com/watch?v=VhDuAN0ouoE

Do AMD FX CPUs Bottleneck Fast GPUs?

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