Will my GPU bottleneck with my CPU?

[whufc12]

I am upgrading to a Gigabyte GTX 970 but I only have an Intel Core i3 2120 @ 3.30Ghz CPU and I'm wondering if this will affect the performance of my GPU?

Thanks guys

 

[TechyInAZ]

Tremendously. You will get a very significant bottleneck by that CPU, your best option is to upgrade to a i5 2500K or i7 2600K. Or if you have a Z77 motherboard you can put in a ivy bridge i5 3570K or i7 3770K.

 

[barto]

I've always felt that a GPU cannot bottleneck a CPU because a CPU isn't dependent on a GPU.

In games that require more than two cores, there may be a performance hit. But for the most part you'll be fine.

 

[whufc12]

My current motherboard has the H61 chipset which is quite old I think. Which CPU would you recommend?

I don't think that the GPU will bottleneck the CPU I think that it would be the other way round?

 

[photonboy]

Agreed.

It should be a socket 1155 motherboard so I would get the i5-3570 (for non-Z77) or i5-3570K if Z77. I wouldn't bother with an i7-3770K as it's about $100 more and the benefits for most games are small to nothing.

I'm not sure why the 2nd gen CPU was suggested above.

*Simply check your motherboard site and read the "CPU support" list. Note that you may need to update the BIOS.

 

[barto]

Well if you don't want to upgrade the motherboard, an i5-2500 or i7-2600 (or i5 3570 or i7 3770) are great choices. If not, Techy pointed out a great combo.

 

[photonboy]

My current motherboard has the H61 chipset which is quite old I think. Which CPU would you recommend?

I don't think that the GPU will bottleneck the CPU I think that it would be the other way round?

You are partially correct.
People seem to get confused on what a bottleneck is. The guy above said you won't get a bottleneck but may get a "performance hit"; um... they are the same thing.

*A "bottleneck" in a computer means a particular part is slowing things down. Put another way it means replacing that part with a faster part improves things. For example, if you got 40FPS average now and got an i5-3570 and got 55FPS it's obvious your current CPU was the bottleneck.

You can also have the GPU as the bottleneck and these can even swap position in a game. For example, you might have the GPU being the main bottleneck but then have a battle and all those calculations bog down the CPU and it's the choke point.

It depends on what GAME you are playing as well. Tomb Raider is less demanding of the CPU than many games so the bottleneck can be the GPU in many systems. Battlefield 4 can be very demanding on the CPU, and Starcraft 2 can toggle back and forth depending on your CPU and GPU choices.

 

[barto]

You are mostly correct.
People seem to get confused on what a bottleneck is. The guy above said you won't get a bottleneck but may get a "performance hit"; um... they are the same thing.

*A "bottleneck" in a computer means a particular part is slowing things down. Put another way it means replacing that part with a faster part improves things. For example, if you got 40FPS average now and got an i5-3570 and got 55FPS it's obvious your current CPU was the bottleneck.

You can also have the GPU as the bottleneck and these can even swap position in a game. For example, you might have the GPU being the main bottleneck but then have a battle and all those calculations bog down the CPU and it's the choke point.

No that's not what I said. A bottleneck is when a component is limited by another. A GPU cannot be a bottleneck. It doesn't limit any other component. It's simply lower results than desired. If a GPU pushes data back to the CPU and the CPU doesn't keep up, that's again the CPU. The GPU is it's simplest form an output.

As for the CPU limiting the GPU in this situation, yes there will be a performance hit in core based games.

 

[Karadjgne]

Almost right, there is absolutely no way a gpu can slow down a cpu, its impossible. The i3 will run at 3.3GHz no matter what the gpu does. No games require 100% load on a cpu, so it matters not what power the cpu puts out. What matters is # of cores, speed and cache.

The i3 has hyperthreading, which will help considerably although not as much as a true 4core like the 3750. 3.3GHz is fine as most games req a minimum speed of 3.2GHz. What's going to hurt is the size of the cache. It just won't be able to process the amount of information in a timely manner.

What all this means is that with a powerhouse gpu like a 970, the cpu is not strong enough to fully utilize it's capability. The cpu will work at its best, but the gpu will only output what it can get from the cpu. This is not a bottleneck, just an unbalanced system. A bottleneck would be a strong cpu like the 3570 supplying plenty of information to the gpu, and the gpu not being able to output what was, imputed, slowing down the flow of data, not the components themselves.

 

[whufc12]

So say for example, Battlefield 4, what FPS do you think I would get on that game?

 

[barto]

So say for example, Battlefield 4, what FPS do you think I would get on that game?

As photonboy said, BF4 is very CPU demanding and thrives when using Intel quad cores or AMD octo-cores.. The CPU will definitely hold back the 970 GTX from it's full performance in BF4 multiplayer. Single player is pretty scripted. You probably couldn't tell the difference between an i7 or an i3 in single player no matter that GPU you have. That's my point.

A 970 GTX can easily play BF4 on Ultra @ 1080 sustaining 60+ FPS. But the i3 will limit that. A quad core is really needed to play that game.

 

[RazerZ]

I'm not sure why the 2nd gen CPU was suggested above.

Sandy Brdige to Haswell, barely a difference in performance.

 

[Karadjgne]

i3 2120 is right at 'recommended', the 970 is way past 'recommended' both of which are well beyond minimum req's. You should be getting seemless play at high detail settings, but if you are looking for ultra then expect some choppiness.

 

[photonboy]

You are mostly correct.
People seem to get confused on what a bottleneck is. The guy above said you won't get a bottleneck but may get a "performance hit"; um... they are the same thing.

*A "bottleneck" in a computer means a particular part is slowing things down. Put another way it means replacing that part with a faster part improves things. For example, if you got 40FPS average now and got an i5-3570 and got 55FPS it's obvious your current CPU was the bottleneck.

You can also have the GPU as the bottleneck and these can even swap position in a game. For example, you might have the GPU being the main bottleneck but then have a battle and all those calculations bog down the CPU and it's the choke point.

No that's not what I said. A bottleneck is when a component is limited by another. A GPU cannot be a bottleneck. It doesn't limit any other component. It's simply lower results than desired. If a GPU pushes data back to the CPU and the CPU doesn't keep up, that's again the CPU. The GPU is it's simplest form an output.

As for the CPU limiting the GPU in this situation, yes there will be a performance hit in core based games.

Incorrect.
From Wikipedia:

"In engineering, it refers to a phenomenon where the performance or capacity of an entire system is limited by a single or small number of components or resources."

Thus a weak GPU is limiting the performance of the system so it is the bottleneck.

(You seem hung up on the CPU. If you want to analyze this way then the GPU is the bottleneck point to the OUTPUT being higher. i.e. the signal to the monitor. If the CPU is giving the GPU data and the GPU is working 100% as it can't keep up then it's a choke point.)

 

[Karadjgne]

Close. Let's say the flow of data is a numeric value of 1-10. Data starts at the hdd, 10, to the ram, 10, to the cpu, 6, to the gpu, 6, to the monitor, 6. Here, the bottleneck to the flow is the cpu. What it is not doing is bottlenecking the gpu, whether the gpu can handle 10 or not. It bottlenecks the flow of data is all. The gpu is most likely under utilized, but considering most games even on ultra graphics don't use 100% of the gpu or even the cpu, bottlenecking becomes a moot point. At the end of the day, you may as well say that for a gtx970, 1080p on a 60Hz monitor is a waste, as a gtx970 is extremely capable of putting fps in the 100+ range and you want to bottleneck it at 60?

Bottlenecking is an extremely overused, misunderstood, asinine terminology used to explain the balance or lack thereof between a cpu and a gpu, and I for 1 would be happy if the term just up and disappeared.