Why Hyper-threading is worthless.....
I have been a Computer Scientist for decades. My foray into computers started with digital electronics in the 70's as a curious kid and snowballed from there. I have built computers by hand, no not buy parts and plug it together, I'm talking buy chips, design the board, etch copper and solder, then write the software for it.
With that background, I want to explain why I personally think that hyper-threading is 100% useless today. Multi processing or Multi Core, IS useful. but hyper-threading is not for a big reason. Most software, even today are not multi threaded. This makes your 4 core 3.5GHZ monster machine, with hyper-threading turned on, act like a old slow 1.7ghz Pentium 4 from 75 years ago. Even modern Video editing software and Graphics software do NOT use multiple threads for anything but the rendering process.
for example: I have a shiny new i5 3.32GHZ quad core video editor. I buy Sony Vegas 9 pro and install it and then spend 3 days trying to figure out why it''s slow as a dog EXCEPT for rendering. It will render a project insanely fast, but the program is sluggish and acts like it's running on a Slow machine. the reason was Hyper-threading was ON in the Bios. This cut all 4 cores in 1/2 and gave me 8 processors with 1.7ghz speed. Super fast for render, useless for 90% of computer uses. when I turned off hyper-threading EVERYTHING sped up 2 fold. The whole computer acted as if it was twice as fast. Games ran super fast, everything.
Why? because 99.997% of all the software out there is STILL written for single processors, single threading. and it will stay that way for a long time because it's simply far easier to do that than write a complex program multi threaded for the UI and basic functions.
So speed up your computer. TURN OFF HYPER-THREADING. And this worked on the low end i3 Dual core. that computer also sprang to life after hyper-threading was disabled. Even the Old P4 that I use for ripping DVD's significantly sped up by disabling hyper-threading and going to single process single threading.
This is my personal experience. I strongly suggest you try the same experiment and see if you get benefits from disabling hyper-threading.