CPU bottleneck

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Freyland
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CPU bottleneck

Post by Freyland »

I only recently learned this was a "thing" when it comes to graphics.

How much of a bottleneck, with today's games, am I likely to experience using an I-7-6600K CPU with my soon-to-arrive RTX 2080ti?
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NickAragua
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Re: CPU bottleneck

Post by NickAragua »

I don't know about your specific hardware, but when I first started playing XCom 2, the game would chug chug chug. I had a good graphics card, but an old two-core processor. Once I upgraded to a four-core processor, the game ran smooth as butter. So "CPU bottleneck" is definitely a thing.
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Isgrimnur
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Re: CPU bottleneck

Post by Isgrimnur »

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Fortunately, there's one easy test to figure out whether you'll have a CPU bottleneck: Monitor the CPU and GPU loads while playing a game. If the CPU load is very high (about 70 percent or more) and significantly higher than the video card's load, then the CPU is causing a bottleneck.
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Freyland
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Re: CPU bottleneck

Post by Freyland »

Thanks, Isg. I will read up on it.
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Zitterbacke
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Re: CPU bottleneck

Post by Zitterbacke »

In this comparison the latest Intel CPUs for roundabout $450 will be faster by 40-50%. So if you find your i5 (there is an i5 6600K, but I couldn't find an i7 6600K?) is a bottleneck, then this would be the possible boost. Congrats on the 2080Ti, anyways!
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gameoverman
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Re: CPU bottleneck

Post by gameoverman »

The way it works is the higher the resolution, the more demand is placed on the videocard. So the reverse is also true, the lower the resolution, the more your CPU becomes the bottleneck.

Complicating this is that 'higher resolution' is a relative thing. Compare it to the card, then you'll know. A 2080 Ti is meant to be run far higher than at 1080p, so if you use it to game at 1080p you are running at 'low' resolution. Your CPU would be the bottleneck here.

Complicating it further is the fact that not all games have the same demands. Some games will be bottlenecked by a 4 core/4 thread CPU regardless of what videocard you have.

Complicating it further is the fact that while standard refresh rates on monitors is 60hz, more and more gamers are using higher refresh rate monitors. If you are one such gamer, then even at a lower resolution you'll be placing larger demands on the card. For example, if you are looking for a solid 144fps framerate on a graphically demanding game your videocard will be working a lot harder at 1080p and so a much more powerful card is useful at that resolution.
Freyland
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Re: CPU bottleneck

Post by Freyland »

35 inch 3640(?)x1440 at 120hz. Good, by your logic I am replacing the more likely bottleneck. (Was a GTX 1070).

I keep forgetting to check the CPU rating to confirm 6600k, will try to remember today.
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gameoverman
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Re: CPU bottleneck

Post by gameoverman »

Yeah, for that setup you could definitely use a lot more than a 1070.
Freyland
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Re: CPU bottleneck

Post by Freyland »

6700K. So close....
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gameoverman
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Re: CPU bottleneck

Post by gameoverman »

With an i7 of that recent vintage you should be alright as far as CPU goes. And by that I mean you'll get your use out of that monitor.

Keep in mind that some games, especially 'early access' games, are poorly optimized so your performance might not be impressive in those games. That won't be because of your CPU or your 2080 Ti, it'll just be because the game runs like crap for everyone.
Freyland
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Re: CPU bottleneck

Post by Freyland »

Card arrived Monday, still haven't had time to install the damn thing.
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Freyland
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Re: CPU bottleneck

Post by Freyland »

Card installed on Saturday. Nothing fried (yet). Able to get 60-90 fps on TW: Warhammer 2 with better settings than I had previously. That's pleasing.
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Freyland
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Re: CPU bottleneck (New technical question)

Post by Freyland »

So, as many of you may have read, there are a decent number of complaints about RTX 20-series cards having serious issues; sometimes DOA, some seem to develop artifacts after a few days use, some are causing BSOD (which may be related to multiple monitors). I have been blessed to thus far have none of these in my roughly 15 hours of active use, plus leaving the PC on while at work. However, I am aware of a scenario where one User's card was 'stuck' at the base clock rate, without automatically taking advantage of the boost clock, and becoming unstable with any attempts to OC beyond the base-clock. Now, I don't know a thing about overclocking, but I would like to know my card is fully functioning. How can I determine this? I did download GPU-Z, which identified my card correctly and listed both the base clock as well as the boost clock correctly, but I don't believe that "tests" anything, rather just reads what the card bios says. Any guidance would be appreciated. Thanks!
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Zitterbacke
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Re: CPU bottleneck

Post by Zitterbacke »

Usually the manufacturer of the card "blesses" you with some software they want to install (or can be downloaded from their site), in which you can set OC to various degrees, within safe ranges. I'd do so and let some kind of Benchmark running, or just play a demanding game and see how that goes.
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Freyland
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Re: CPU bottleneck

Post by Freyland »

Zitterbacke wrote: Thu Nov 08, 2018 6:07 pm Usually the manufacturer of the card "blesses" you with some software they want to install (or can be downloaded from their site), in which you can set OC to various degrees, within safe ranges. I'd do so and let some kind of Benchmark running, or just play a demanding game and see how that goes.
Funny enough, this is the first card I have ever bought that didn't come with any sort of disk, despite being brand new. I think Nvidia believes if you know how to order from their site, you know how to download drivers! In any case, I am waiting for Nvidia to release their "Scanner" tool to see what that's like.

On the topic of my question, it looks like GPU-Z actually does have a "sensor" function which monitors the clock hz, and my card happily fluctuates its speed as needed, actually higher than the boost clock advertised. Still hasn't crashed yet, thank God, but I have not tried the final litmus test of running some AAA title with all the bells and whistles.

I admit I'm ignorant of things, but I am still a little surprised that on TW: Warhammer 2 I can't have everything maxed out and reach a consistent frame rate of 60, but part of that is likely the reportedly poor optimization of that engine, and also the massive real estate of the monitor I'm using.
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gameoverman
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Re: CPU bottleneck

Post by gameoverman »

What I do when testing a new card is run MSI Afterburner as I play a game. You can configure it to show onscreen displays of various things, like framerate. In your case you'd want it to show the GPU clockspeeds. You should then see your standard clockspeed, then if it boosts to anything higher you'll see that too.

edit: MSI Afterburner can also show you the CPU and GPU usage percentage. So if your framerate hits a low point and the CPU is at 100% usage while the GPU is at 70%, then you know the reason is the CPU is holding back performance.
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Jag
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Re: CPU bottleneck

Post by Jag »

I'm in the market for a new card as well. I have a Acer XB270HU Gsync (1440) and was hoping to game at the higher resolution. I actually do have the i5-6600K. I'm currently running an old 970 but I'm going to replace it with either a 1070ti or a new 2070. Not sure yet.

I didn't even think about the CPU bottleneck. Maybe I'll settle for the less expensive 1070ti now and do a CPU/Video card upgrade in another year or two.
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