Question cores vs threads in gaming

[aleksander.wind]

i want to get a new cpu, but i dont know if i should get the 9700k (8c/8t) or the 8700k (6c/12t). It is the same price for me, but should i choose more cores with less threads or the other way around? The purpose of my pc is gaming.

 

[Shektron]

In very rare cases, the 8700K might actually be better, due to the fact that it has more threads, hence better multi-thread performance. For pure gaming, there's probably not going to be much of a difference in current games, so I would suggest the 8700K since it'll probably be a bit easier to overclock and you don't need to bother checking the BIOS of your motherboard or buy a more expensive Z390 board.

 

[geofelt]

The i7-9700K will outperform the 8700K, regardless of now many threads can actually be utilized.
I7-8700k has a total passmark rating of 15962 and a single thread rating of 2702.
The i7-9700K has a total rating of 17238 and a single thread rating of 2823.

For gaming, the single thread performance is usually the limiter.

 

[aleksander.wind]

thank you both, but do you think that upgrading to one of those processors is worthy? since i am using an 8500 at this moment and i think it is a bottleneck for my 2x1070ti's

 

[sizzling]

Well you need to prove your cpu is the limiting factor. What resolution are you gaming at? When gaming how many cpu cores are hitting 100%?

If you lower the resolution what happens to the FPS?

It’s possible the limitation is poor sli support.

 

[geofelt]

Worth, of course is something only YOU can determine.

What you would get would be two more cores and faster single thread performance.

Try a couple of tests.

Limit your cpu, in windows power management, limit the maximum cpu% to something like 80%.
Go to control panel/power options/change plan settings/change advanced power settings/processor power management/maximum processor state/
This will simulate what a lack of cpu power will do.
Conversely what a 20% improvement in core speed might do.

To see how many threads you can effectively use,
experiment with removing one cores. You can do this in the windows msconfig boot advanced options option.
You will need to reboot for the change to take effect. Set the number of threads to less than you have.
This will tell you how sensitive your games are to the benefits of many threads.
If you see little difference, your game does not need all the threads you have.

SLI gives you nice synthetic fps benchmarks, but your gameplay may be better with a single good card.
Dual gpu is prone to stuttering and screen tearing.
Some games do not support dual gpu.

 

[InvalidError]

i am using an 8500 at this moment and i think it is a bottleneck for my 2x1070ti's

You may want to look around to see how well whatever games you play scale with SLI. It could simply be that a large chunk of your "missing performance" is due to your games not handling SLI particularly well. Since implicit multi-GPU like SLI and Crossfire do not scale well unless the game has been written with some degree of explicit support for it, AMD and Nvidia are both scaling back implicit multi-GPU in favor of letting game developers implement explicit multi-GPU instead if they really want multi-GPU support.

Most games that haven't been developed with multi-GPU support in mind show little to no performance scaling, many even perform worse. You may want to try benchmarking your games with one vs two GPU installed and compare results.

 

[TerryLaze]

To see how many threads you can effectively use,
experiment with removing one cores. You can do this in the windows msconfig boot advanced options option.
You will need to reboot for the change to take effect. Set the number of threads to less than you have.
This will tell you how sensitive your games are to the benefits of many threads.
If you see little difference, your game does not need all the threads you have.

Task manager, details tab, right click and set affinity this changes available threads even in real time while the game is running,no need to mess up your whole system multiple times.

 

[InvalidError]

Task manager, details tab, right click and set affinity this changes available threads even in real time while the game is running,no need to mess up your whole system multiple times.

Process Explorer is much better for this. Find the game in the process list, open the properties tabs, look at how much CPU usage each thread produces under the threads tab. If only one thread is at 100% utilization (would show up as 16.6% for 6C6T, the main control thread is almost always a busy-wait loop with 100% utilization regardless of FPS and how fast the CPU is) and the sum of others is significantly less than remaining CPU, then any CPU bottleneck there might be is due to single-thread performance (plenty of CPU time available but individual tasks aren't being completed fast enough) and would only get better with higher clock and IPC.

For an SLI setup though, I'd start with removing or disabling a GPU if the performance issues are with games that do not explicitly support SLI.