May 14th, 2013, 03:10
Hyperthreading? Not on my rig!
IF an application IS heavily threaded, which our sims are not, HT can be of great benefit.
On a Quad Core CPU that is HT capable, there are still only 4 Physical Cores.
Each Physical Core includes a single Physical Execution Unit(PEU).
The two Virtual cores(VC1, VC2), the second of which is enabled with HT=ON, share the PEU.
With HT=On, the PEU data threads flip-flop between VC1 and VC2. While one Virtual Core is processing data, a miniscule wait state is generated, and data is held in a buffer, until the PEU addresses the other VC
With HT=ON, if both Virtual Cores, of a Physical Core, are given affinity to FSX, basically there should be very little harm done, because FSX has exclusive use of the PEU and FSX "only" data is being processed.
Most of us limit use of other applications, and minimize background apps, while running our sims, so, in reality, a proper Affinity Mask can alleviate most HT=On bottlenecks.