"Bottleneck". You keep using this word.

[aisle9]

I do not think it means what you think it means.

 

Maybe I'm just noticing it more, but it seems like that twelve-letter word is being thrown around here (and other sites) like crazy recently, maybe since Pascal launched? It almost seems like people are afraid to upgrade their GPU because they don't want the CPU holding it back, and that's a valid concern, but hear me out on this: a bottleneck is not the end of the world. It's not a doomsday scenario where you've just thrown away hundreds of dollars on hardware you'll never realize the full benefits of. In fact, some bottlenecks are a good thing. First, a few sentences to explain what a bottleneck is and why it happens, and then a few common bottleneck situations and the relative merits or demerits of each.

 

First off, what is a bottleneck? There are YouTube videos exploring this concept, but I'll boil it down to a few sentences. Imagine a 16 oz. bottle of water, then a 16 oz. cup of water. Flip them both upside-down at the same time. Which one empties first? The cup. Why? Because the bottle has a tapered neck that narrows and directs the flow of water out, whereas the cup is just a straight, cut edge. How does this relate to PCs? Imagine that the CPU and GPU are each upside down bottles that are being constantly poured into. Inevitably, one or the other will be more powerful and, thus, a larger bottle. It's on the bottom. So when the smaller bottle/weaker component on top isn't pouring as quickly as the bottle on bottom, you end up with the bottom bottle being held back from its maximum pour potential by the top. Same principle applies to PCs, particularly the CPU/GPU relationship.

 

So when is a bottleneck bad, and why would it be a bad thing? Well, here's an example. Let's say that Johnny finds an old Dell Optiplex prebuilt online at a screaming deal of a price. i5-2400 with 8GB of RAM and a 1TB hard drive for $100. Johnny is thrilled with his find, knowing that he can make a killer gaming rig out of it, so he goes and buys a shiny new GTX 1080 for it, then is shocked and infuriated when his prized find is only pulling 45 FPS on GTA V and less than that on Hitman at 1080p.

 

So what happened? Two things. The first is obvious: Johnny didn't do his homework on the i5-2400 and its limitations. If he had, he might have seen that a GTX 1060 or RX 480 would have been a better fit for what that CPU is capable of. As a result, a CPU-bound game like GTA V is going to perform terribly on an older or weaker CPU, regardless of how powerful the GPU is. Because Johnny didn't do his homework, he now has a $600 GPU from 2016 in a $100 system from five years ago, and because Johnny bought a $600 GPU, it's probably safe to say that he's not upgrading anytime soon. In short, Johnny is a borderline idiot.

 

The second issue is that Johnny didn't do his homework before buying a GPU. Hitman is notoriously poorly-optimized for NVIDIA hardware. If one of his major use cases was Hitman, a few minutes of research would have shown him that the RX 480 or R9 Fury would have been a much better choice. In this situation, we're not even looking at a bottleneck, and it's important to draw that line. There is a difference between a CPU or GPU badly overmatching the other, and a fairly balanced setup that just isn't optimal for the games thrown at it. This isn't a bottleneck; it's just Johnny not spending enough time planning out his rig before throwing things at it.

 

Moral of the story for the above? If you spend time planning out your rig instead of just grabbing parts, you'll avoid being in Johnny's situation. If getting that GTX 1070 means you can only afford an i3, maybe it's time to step down to a 1060 and get yourself an i5-6500 to go with it instead--a much more balanced and cost-effective PC.

 

But not all bottlenecks are bad. How so? Well, we've established that Johnny is a moron, so let's take Bobby as our next example. Bobby has a plan for his PC: He wants to play AAA titles at 1440p. He wants this PC to last for at least three years doing that. He knows that his budget is $800, and that he'll need a GTX 1070 to accomplish his goal. Bobby also knows that getting a GTX 1070 and 1TB SSD at that price means he won't have room for an i5-6500 in the budget. The best he can do while still getting the quality of parts he wants is a G4400. Knowing that he's going to be dumping gallon jugs into a thimble with that combination, he goes ahead and makes the purchase. Bobby's a moron, right?

 

Wrong. See, Bobby knows that over the course of the next few months, he'll be able to save up enough for an i5-6500. If he waits four or five months, he'll be able to grab an i7-6700 if it looks like games are coming out that make use of eight threads. Bobby isn't dumb. He's the exact opposite of Johnny. He bought a GPU that painfully overpowers his CPU and creates a massive bottleneck, but Bobby's got a good bottleneck on his hands. His bottleneck comes with a purpose--letting him take advantage of the great December deals to build a PC today and round it out later into a balanced rig that will hold up for several years as a AAA gamer.

 

A third scenario: Joe. Joe has an Athlon X4 860K. Joe's rig is done for within the next year, and he knows it, and he knows that he's going to build a rig with an eight-core RyZen CPU, but he also knows that RyZen won't be available for another couple of months. Thing is, he's on Craigslist, and he sees someone local selling a GTX 1080 for $500. That 1080 is going to be choked practically to death by his 860K, but the deal is so good that it almost has to be taken, and Joe already has a plan to replace his ancient PC with something modern. In this case, yes, he's severely hampering his 1080...but who cares? He has a long-term plan to bring his PC up to a spec where it can take advantage of the 1080's power, so sacrificing that cost/value proposition now isn't an issue for later.

 

And that's ultimately the point I'm getting at. Bottlenecks are not inherently bad. If they're a result of poor planning that leaves someone stuck with a Sandy Bridge CPU, a high end Pascal GPU and no upgrade path for the foreseeable future, then yes, that is a terrible bottleneck to have. But if you're saddled with a bottleneck, either CPU or GPU, because you're taking advantage of deals to get the PC you want at better prices, or to be able to afford it in the first place, then that's a great bottleneck "problem" to have. It's all about doing your homework. If you just buy parts for the sake of buying parts, you're going to end up with an unbalanced rig that has a CPU running at 100% usage while the GPU is barely breaking a sweat. Read reviews, check benchmarks, ask questions, track prices, check tech forums for user experience with the combination you're looking at and work with a budget. Be Bobby. Be Joe. Don't be Johnny, with his $700 rig that's going to be outperformed by a $500 one.

[jeffmeyer5295]

2 minutes ago, aisle9 said:

...

Very well written! 

[The Belgian Waffle]

Please do a TL;DR, this is really too long to read for such an easy concept

[79wjd]

I'd actually still call Bobby and Joe morons because had they waited four or five months Vega would be out and GPU prices would likely have fallen to below what they paid anyway. 

[The Belgian Waffle]

1 minute ago, wrathoftheturkey said:

^

 

That said, idgaf which GPU you have, if you want to play Battlefield One you're getting a damn 6700k

Same thing if you wanna play Minecraft at dem steady FPS

 

[Thony]

I was like "I am gonna reply to this" before I saw that Trump wall of text. Im done

Some people use it properly and some dont.

 

[aisle9]

6 minutes ago, The Belgian Waffle said:

Please do a TL;DR, this is really too long to read for such an easy concept

If it's such an easy concept, why do new and veteran builders alike constantly go into threads here, on PCPP, on reddit, wherever and scream that you can't pair a 1060 with a G3258, even after the OP has stated that the G3258 is just a placeholder?

 

tl;dr, stop bitching about bottlenecks everyone.

 

4 minutes ago, djdwosk97 said:

I'd actually still call Bobby and Joe morons because had they waited four or five months Vega would be out and GPU prices would likely have fallen to below what they paid anyway. 

This was not written without that knowledge, but it's hard to use it as a bottleneck scenario without making things far longer than they already were. Maybe intentionally pairing a 6700K with an old 950 in anticipation of Vega? Still, I think it's way too long as is, and I really wanted to capture the three types of GPU bottlenecks I see all the time,

[Clyne]

What if you get your parts for free?

I got a free A8-5600K and paired it with a RX 470 as I couldn't pass up on the price. 

I upgraded from a 270X to a Fury and it gave me a massive FPS boost, and I'm happy with the performance 

While my 8320 is bottlenecking my 8320, it's not that bad.

[aisle9]

1 minute ago, Bubblewhale said:

What if you get your parts for free?

I got a free A8-5600K and paired it with a RX 470 as I couldn't pass up on the price. 

I upgraded from a 270X to a Fury and it gave me a massive FPS boost, and I'm happy with the performance 

While my 8320 is bottlenecking my 8320, it's not that bad.

The best component is a free one. I'll never argue that free stuff is a bad bottleneck unless it's like you're throwing a 1060 into a trash-picked Pentium D machine or something.

[Mick Naughty]

Managed to get my 4790k to work in bf1 on a 1440. Cant handle surround 1080 though. "Bottle neck"

[App4that]

You forgot the most common bottleneck in existence. The monitor. Everyone freaks out worried their 6600k might bottleneck their GTX 1080, while using a 1080p 60hz WalMart special from black Friday. 

[aisle9]

4 minutes ago, App4that said:

You forgot the most common bottleneck in existence. The monitor. Everyone freaks out worried their 6600k might bottleneck their GTX 1080, while using a 1080p 60hz WalMart special from black Friday. 

I don't know if I'd consider that a bottleneck or just blind ignorance.

[Prysin]

1 hour ago, aisle9 said:

snip

sorry but you're the moron. The worst kind of bottleneck is the CPU. When the CPU bottlenecks you get massive stuttering. This is exactly why we all say dont buy AMD FX CPUs if you can afford a i5.

 

The only "good" bottleneck is GPU bottleneck. Because you can always lower graphics settings, and GPU bottlenecking doesnt cause stuttering or lag, It only reduces your FPS. But you cannot alter much of the CPU intensive settings like physics, drawcalls, AI and such these days. Thus the CPU has to be good enough.

 

Buying a G4400 with a 1070 would make bobby the worst moron ever. He will have insane stuttering, poor frame delivery and worst of all -> no way to fix it, until he can get an i5 6600k. The G4400 is also a low end SKU, so it wont be easy to sell on the used market. He will NOT get back 100% of his investment, and as such he wasted his money getting the G4400 as a "stopgap" solution. That being said, the 1070 is in fact so fast, that in some games even a i5 6600k is no longer enough. As the i5 is hitting 80-100% utilization across all four cores. Causing stuttering.

 

This is really bad.

 

5 minutes ago, App4that said:

You forgot the most common bottleneck in existence. The monitor. Everyone freaks out worried their 6600k might bottleneck their GTX 1080, while using a 1080p 60hz WalMart special from black Friday. 

Sometimes, its not even the monitor causing the bottleneck. 6600k is not good enough anymore. Digital Foundry has proven it with a 1070. 2 more years and the 6600k wont be able to power AAA titles. You'll be needing a i7 if you are going to have any chance at all.

Also, i take it your PC is working again, so you coming on skype the next few days?

[App4that]

1 minute ago, Prysin said:

-snip-

DF went console, they can kiss my ass. A 6600k is more than enough for 1440, all it takes is some adjustments to the useless settings games have been shipping with recently. 

 

Yeah, haven't broke out my laptop yet. Got some time off so I'll be on. Need some advice anyway.

[Prysin]

3 minutes ago, App4that said:

DF went console, they can kiss my ass. A 6600k is more than enough for 1440, all it takes is some adjustments to the useless settings games have been shipping with recently. 

 

Yeah, haven't broke out my laptop yet. Got some time off so I'll be on. Need some advice anyway.

DF still does desktop better then any other "mainstream" reviewers. They still test frame timing, which is a million times better test method then avg. FPS bullshit that LTT, Jayz, HWC and others churn out.

 

That being said, they have been on a seriously bad console streak atm, i guess it's because there hasnt been any interesting AAA titles or any new PC hardware worth testing.

[Mitchell 3]

12 minutes ago, App4that said:

You forgot the most common bottleneck in existence. The monitor. Everyone freaks out worried their 6600k might bottleneck their GTX 1080, while using a 1080p 60hz WalMart special from black Friday. 

I lol'd

[aisle9]

11 minutes ago, Prysin said:

6600k is not good enough anymore. Digital Foundry has proven it with a 1070

Oh good god, not that crap again. If you want to run 4K at 60 FPS or 1080p at 144 FPS ultra with VSync, sure, you need more than an i5-6600K.

 

But then, if you're running 4K 60 or 1080p 144 FPS ultra with VSync, you're probably not the type of person who has a budget to worry about that would constrain you to a 6600K, are you?

 

I certainly appreciate the feedback, and yeah, there are other bottlenecks. Everything in life is a bottleneck: at some point, the water being poured into bottle A is overwhelming bottle B. This post is specifically about GPU bottlenecks, because those are the ones people latch onto simply because it's a buzz word right now. And, for the record, crappy CPU with a great GPU for a few months is something I've done before to clear budget, as is crappy GPU with great CPU. I'm not just pulling scenarios out of my backside here.

 

That being said, if I'm a moron and my post is really bad, then, with all due respect (and then a bit, given the tone of your reply)  go write your own really bad post about CPU bottlenecks, moron.

[App4that]

1 minute ago, Prysin said:

DF still does desktop better then any other "mainstream" reviewers. They still test frame timing, which is a million times better test method then avg. FPS bullshit that LTT, Jayz, HWC and others churn out.

 

That being said, they have been on a seriously bad console streak atm, i guess it's because there hasnt been any interesting AAA titles or any new PC hardware worth testing.

You mean like the 1050ti, or the multitude of horrible console ports? But I digress.

 

Once we move out of this slump with console ports the need for a i7 should diminish. 

 

 

[Glenwing]

Historically this term was only used for huge mismatches in power (think "Celeron with dual 980s") where someone would ask about upgrading their graphics cards to 1080s, and you would reply saying that it wouldn't do anything because they have a CPU bottleneck, meaning that better graphics cards wouldn't improve performance, they would get the exact same framerate in virtually any application. Thus it is a waste, because the power of the new hardware would never be utilized. The term "bottleneck" really only applied in situations where you could use it as a sweeping term to describe the whole system; that CPU is bottlenecking your system, period. Not "in this game" or "in that application"; in virtually almost anything.

 

I do sometimes despair at how people now use this word to describe the tiniest performance fluctuations; nothing is more annoying than hearing someone say the CPU is "slightly bottlenecking" your GPU or vice versa... This is practically an oxymoron. With such a wide variation in the ratio of CPU to GPU power required by a game, the answer to the question "which one will be the limiting factor for performance: my CPU or my GPU?" has no definitive answer for most hardware combinations. The term "bottleneck" really only applies to the most extreme mismatches. The way people use it today, for more trivial mismatches, means that there's a separate answer depending on every application. But the problem is when people talk about bottlenecks, they use phrasing which implies there is a simple Yes/No answer to the question "will I have a bottleneck?", mostly because may years ago the term was only applied in situations where there WAS a yes/no answer, and we still use the old phrasing and language from that time.

[Deli]

Oh, my 5820K @ 4.5GHz bottlenecks my GTX750 Ti. What can I do........

[aisle9]

Just now, Deli said:

What can I do........

Render! 

[Prysin]

29 minutes ago, aisle9 said:

Oh good god, not that crap again. If you want to run 4K at 60 FPS or 1080p at 144 FPS ultra with VSync, sure, you need more than an i5-6600K.

 

But then, if you're running 4K 60 or 1080p 144 FPS ultra with VSync, you're probably not the type of person who has a budget to worry about that would constrain you to a 6600K, are you?

 

I certainly appreciate the feedback, and yeah, there are other bottlenecks. Everything in life is a bottleneck: at some point, the water being poured into bottle A is overwhelming bottle B. This post is specifically about GPU bottlenecks, because those are the ones people latch onto simply because it's a buzz word right now. And, for the record, crappy CPU with a great GPU for a few months is something I've done before to clear budget, as is crappy GPU with great CPU. I'm not just pulling scenarios out of my backside here.

 

That being said, if I'm a moron and my post is really bad, then, with all due respect (and then a bit, given the tone of your reply)  go write your own really bad post about CPU bottlenecks, moron.

you do realize that resolution only affects the GPU?

in which case, if a Athlon x4 860k is enough to get 60FPS at 480p, it will be good enough to get 60 FPS at 8k too. The limiting factor for CPUs are not the resolution but the physics, AI, events, flags, networking and drawcalls. The CPU makes as many drawcalls as it can. If it can make enough drawcalls to get 60FPS, then the CPU isnt the bottleneck (assuming a 60Hz monitor).

 

No offense, but given your amount of posts, i would assume you knew this. Perhaps it is my fault for taking online classes in computer science and graphics, allowing me to actually learn some facts about how things work. Ignorance is bliss after all.

[Glenwing]

4 minutes ago, Prysin said:

you do realize that resolution only affects the GPU?

in which case, if a Athlon x4 860k is enough to get 60FPS at 480p, it will be good enough to get 60 FPS at 8k too. The limiting factor for CPUs are not the resolution but the physics, AI, events, flags, networking and drawcalls. The CPU makes as many drawcalls as it can. If it can make enough drawcalls to get 60FPS, then the CPU isnt the bottleneck (assuming a 60Hz monitor).

 

No offense, but given your amount of posts, i would assume you knew this. Perhaps it is my fault for taking online classes in computer science and graphics, allowing me to actually learn some facts about how things work. Ignorance is bliss after all.

Cut the condescending tone.

[Prysin]

32 minutes ago, App4that said:

You mean like the 1050ti, or the multitude of horrible console ports? But I digress.

 

Once we move out of this slump with console ports the need for a i7 should diminish. 

 

 

even with low levels APIs, like DX12 and Vulkan, developers will just push more and more work for the CPU.

 

If you can, by changing API, free up, say 20% CPU resources.. then i promise you, those 20% will be spent on TressFX/Hairworks or similar physics based eyecandy systems. That or more complex weather systems with even more complex "cycling" effect. Aka change of NPC activity etc.

 

You will NOT get those 20% to improve FPS by making the game simply easier to run. Oh no, they will stuff more and more stuff into the game just to wow users.

 

Games are getting more and more demanding, and it seems like developers are almost "leapfrogging" the quad core/quad thread era. Going straight from dual-core/quad thread optimized setups, straight to quad-core + HT setups.

 

Within 5 years, an i7 will be the minimum you should get with a XX70 or XX90 series from Nvidia or AMD. Mark my words, we are going in that direction.

[Prysin]

13 minutes ago, Deli said:

Oh, my 5820K @ 4.5GHz bottlenecks my GTX750 Ti. What can I do........

get a G4400 and save money for a i5 6600k according to the OP