FX-8320 disabling cores to boost clock speed

[johnrob]

I have another thread up where I was trying to overclock my FX-8320 on an MSI 970a-g43 board. Which most people say is impossible, and I'd tend to agree. I wasn't getting good results.

I noticed power delivery was a problem and on any significant OC I had at least 1 core fail on p95.

I disabled cores 5-8 in my bios and am in the process of testing a 4.6 mhz turbo clock with most settings turned to auto in the bios. I seem to be pretty stable so far (about 10 minutes or so)

I've also noticed that my Core #0-3 VID's are hitting 1.413V. When I had all 8 cores enabled I could only get 1.363V.

Do you guys think this would be a good way to run if my only goal for this PC was for gaming?

I played far cry 4 for a bit but it seemed to only use 4 cores at a time.

Share your thoughts please!

 

[Darkbreeze]

By disabling cores, in order to gain clock speed, you are not really increasing performance at all. If you compare dual core CPUs like the G3258 to the FX-8320, it's single and dual core performance only shines with a really high overclock when compared to the FX 8 core units.


And if overclocked to an equal frequency, the FX regains the advantage. Of course, it's not the same case with the quad core i5's, as they have a higher number of instructions per second so at equal clock speeds, the i5 and i7 just outshine the FX, but with that 8320 you would have better performance at stock speeds with the turbo enabled than with only 4 cores enabled and overclocked.

As an example, the FX-4350 which has a 4.2Ghz base clock, when compared to an FX-8320 with it's 3.5Ghz base clock, performs at the exact same performance level when it comes to discrete graphics performance, as seen here. Since discrete graphics performance is what the main consideration should be when gaming, you can see there is no advantage in gaming by shutting off four cores and overclocking the remaining cores. Plus, for other threaded applications, the performance level will drop CONSIDERABLY with only four cores.

http://www.cpu-world.com/Compare/304/AMD_FX-Series_FX-4350_vs_AMD_FX-Series_FX-8320.html



As far as that motherboard goes, it looks like it's only a 3 phase board, and probably shouldn't have a full time overclock configured whether it can be done, or not.

 

[johnrob]

thanks for the insight. I mainly did it for giggles and to see if it was possible. I'm planning on buying a better board soon (asus m5a99fx pro r2.0)

Still though if a game is just not utilizing 4 of my cores, shouldn't there be a performance increase if I chop 4 cores out and boost the remaining 4?

 

[Darkbreeze]

No. Just because the game isn't using those cores, does not mean the rest of the system isn't. There are still processes that need to be running as well as the core OS kernel, all of which need processing resources. When you drop the CPU down to 4 cores because that's all the game is using, now the system needs to rob some resources from the 4 cores you thought were dedicated only to gaming, in order to keep the rest of the system stable and running. The game has to have a platform on which to operate, and that takes resources beyond the game itself.

I guarantee if you run HWinfo and watch the core activity while gaming, all the cores will be utilized even if they are not all being used for the game itself. Networking, the OS, drivers, all these things need to run.

 

[johnrob]

I am running HWiNFO and msi afterburner. and steam and uplay and logitech gaming software etc.

When Far Cry 4 is running 4 cores are at 75% use and 4 are sitting at 0-1%. This only seems to happen in FC4, every other game I play uses all 8 cores pretty evenly.

I'll try to dig around the config files and see if there's something limiting me to 4 cores in game or something.

 

[Darkbreeze]

This: http://www.pcworld.com/article/2851126/far-cry-4-woes-with-dual-core-processors-point-to-a-bleak-future-for-budget-pc-gamers.html