Should I disable a core on my i5?

[wilds]

I play a lot of RTS games that load all the AI on one core; so I need fast single-threaded performance. I've been trying to get a higher overclock within reasonable voltages, but core 2 (0,1,2,3) of my i5 fails Prime 95 after awhile unless I raise my core voltage ~ 0.02v higher.

If that particular core requires a good bit more voltage than the rest, would I just be better off disabling it to achieve a lower stable voltage?

For smooth fps during large battles, I'd probably need around 2.5x the performance of a 5 GHz Haswell core, but every little bit helps.

Even ARMA 3, a game I play often, is single-threaded bound a lot. I would gladly sacrifice a core for certain games that don't need it.

 

[Jimzz]

Yea disable it and see what happens. Can't hurt to try.

Turn it back on if needed later.

 

[BSim500]

I play a lot of RTS games that load all the AI on one core; so I need fast single-threaded performance.

For smoth fps during large battles, I'd probably need around 2.5x the performance of a 5 GHz Haswell core, but every little bit helps.

I'd love to know exactly what game you have that needs a 12.5GHz Haswell single core CPU! Seriously, you might squeeze 100-200Mhz more out of it (disabling the weakest core), but it's not really the most efficient way to go about it, and certainly won't come close to "2.5x 5Ghz". You're far better off tweaking the options in your game as it sounds more like an impractical / unrealistic desired no of units per player for that game engine (the way it's coded) rather than "weak CPU"?

I own Operation Flashpoint (ARMA's precursor and a purely single thread old game) and even today, you won't get smooth 60 fps on 5km view distance with everything running in 1 thread, even on a top end OC'd 5GHz i7. Some single-core era games like that were just too ambitious for everything to be maxed out. Best to just turn the view distance settings down until you hit the "sweet spot" (fps vs view distance) that's often typical of ARMA games.

Edit : Can you actually disable a specific core in your mboard's BIOS? ie, won't some of them disable Core 4 first (if you select "3 cores enabled") then disable cores 3&4 (for 2 cores enabled) then disable cores 2-4 (for 1 core enabled)?

 

[Rakehellion]

You'll end up losing more performance than you gain. Even if you do have a "weak" core, the others won't be significantly better.


Also, I'm having a very hard time believing there's a title that requires a 5Ghz CPU that doesn't exist, so what game and what CPU are you using?

 

[wilds]

Sins of a Solar Empire and Supreme Commander are 2 RTS games that load the AI onto 1 core.
During large battles with thousands of units, FPS will drop into single-digits. Core 0 will be pegged at 100%.

I wasn't exaggerating when I said I need about 2.5x the current speed of a 5 GHz Haswell core. These older games will peg core 0 until the game slows to a crawl.
Another con of these games is than when the core becomes fully saturated, the AI make choices much slower because they must wait for the cpu core to catch up. Once the game slows down enough, the AI will become really broken for either game.

ARMA 3 is not a game I run at max settings. I'm only talking about specific missions with a lot of AI where the fps drops down to the 20's because it is CPU bound.
Disabling a core could give me an extra 200 mhz, which is an extra 1-2fps which is worth it imo. I'll give it a shot.

I'll just need to see about disabling that specific core
Edit:
BIOS does not have a way to disable specific cores; just enabling 1-4 cores. If I lower it down to 2, I believe the 'weaker' core will be disabled, but I want at least 3 threads.

I'll just have to hope Broadwell will have a 10 GHz SKU

 

[Firetrak]

You disable it in the task manager.

I'd love to know exactly what game you have that needs a 12.5GHz Haswell single core CPU! Seriously, you might squeeze 100-200Mhz more out of it (disabling the weakest core), but it's not really the most efficient way to go about it, and certainly won't come close to "2.5x 5Ghz". You're far better off tweaking the options in your game as it sounds more like an impractical / unrealistic desired no of units per player for that game engine (the way it's coded) rather than "weak CPU"?

I own Operation Flashpoint (ARMA's precursor and a purely single thread old game) and even today, you won't get smooth 60 fps on 5km view distance with everything running in 1 thread, even on a top end OC'd 5GHz i7. Some single-core era games like that were just too ambitious for everything to be maxed out. Best to just turn the view distance settings down until you hit the "sweet spot" (fps vs view distance) that's often typical of ARMA games.

Edit : Can you actually disable a specific core in your mboard's BIOS? ie, won't some of them disable Core 4 first (if you select "3 cores enabled") then disable cores 3&4 (for 2 cores enabled) then disable cores 2-4 (for 1 core enabled)?

 

[BSim500]

You disable it in the task manager.

Surely that won't stop it from locking up though when other tasks / processes / drivers / windows services, etc, continue to run code on it and experience instability related crashes or at least "Event ID 19 - WHEA" errors in Event Viewer? It's not really disabling the core on a hardware level, it's just telling 1 process to not use it (whilst the other 50-odd background processes continue to use it at increased risk of crashing).

 

[Rakehellion]

Increase your single-core turbo speed.

 

[wilds]

Do any Z97 boards have a setting to disable specific cores? If I raise the single core turbo speed, I would still have to raise voltage for the 3rd core to keep stability.

It's not a big deal, but being able to choose which cores to disable would be a very useful trick; especially with benchmarking.


If I go 4.6 GHz+ that 0.02v extra I need to tack on really starts to increase temps.

 

[flash43]

It's not worth disabling the core. If you do this, you may be able to get a extra 100MHz or something but it's not worth it.

By disabling the core you are being another core down, which can even do more harm than good depending on your background processes. It's simply not worth sacrificing a core for a slightly better overclock.

I'd much rather keep 4 cores than have a slightly better overclock which is not going to be noticed 95% of the time.