Should I disable Hyperthreading for Civ 5?

aymanhaq

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I just bought a quad core i7 processor with a total of 8 virtual cores. As this article indicates: http://www.techspot.com/review/320-civilization-v-performance/page12.html , Civ 5 doesn't seem to benefit from HT on quad core CPUs. From my limited knowledge of HT, I understand that each virtual core runs at about 65% of its original capacity which ends up being about 130% performance per core compared to an identical core without HT.

Since Civ 5 only uses 4 cores instead of 8, will turning off HT and hence allowing each core to run at 100% instead of 65% boost performance (assuming CPU bottleneck) and reduce turn-times?
 
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That's not true. While most games do not, there are a few games that do benefit. Resident Evil 5 gains 10% more FPS with HT, same with Metro 2033. BF3 also benefits from HT in multiplayer. More games are starting to see a gain with HT or more than 4 cores, but there still isn't a lot.

Giving the pain it is to disable and enable it, I'd leave it enabled because when you do benefit from it, it is there.

aymanhaq

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Actually, the article above does show that dual core CPUs that have HT show a performance boost in Civ 5. It seems that Civ 5 can use 4 cores, whether physical or virtual, but not more. Also, how do I disable HT for Civ 5, but not other applications?
 

ricardois

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like simon12 said the difference is minimal, and i'm not sure you are able to disable HT only for one application, what you can do is limit it to use only some specific CPUS:

Type in: Control+Shift+Esc to get your taskmanager up.

Click on the Processes tab

Find the process that needs its processor affinity changed

Right-click on the process

Click on "Set Affinity"

Here you can select which processor(s) your process will use.
 


That's not true. While most games do not, there are a few games that do benefit. Resident Evil 5 gains 10% more FPS with HT, same with Metro 2033. BF3 also benefits from HT in multiplayer. More games are starting to see a gain with HT or more than 4 cores, but there still isn't a lot.

Giving the pain it is to disable and enable it, I'd leave it enabled because when you do benefit from it, it is there.

 
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aymanhaq

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I don't think this disables HT. It will just prevent Civ 5 from using the virtual cores. They will remain active and the CPU will still be HTed.
 


True, but it may be a good technique for games which have troubles with HT active. There have been a few games that have had issues with HT at release. Most have fixed the issues over time, but this could be a good way to resolve issues when they arise, without disabling it completely.