[LAU] i5 Hyper-Threading, BIOS settings and Arch n00b pointers

Hello all.

I hope this isn't too rambling a post to get some replies...

I have seen on this list multiple times lately (possibly by the same person, but never corrected) a statement similar to thus:
"I chose an i5 over an i7 as the i5 doesn't have Hyperthreading whereas the i7 does."

I always thought I remembered this as wrong, especially as I believed I was running a 2 core i5 in my laptop and it shows up as 4 cores. I have just confirmed this to be the case. But it is partially correct, so if anybody has been taking this information for recommendation towards a new CPU purchase this appears to be a clearer picture of the situation.

"The quick explanation is that all Core i7 CPUs use Hyper-Threading, so a six-core CPU can handle 12 streams, a four-core can handle eight streams, and a dual-core can handle four streams. Core i5 uses Hyper-Threading to make a dual-core CPU act like a four-core one, but if you have a Core i5 processor with four true cores, it won't have Hyper-Threading. For the time being, Core i5 tops out at handling four streams, using four real cores or two cores with Hyper-Threading."[1]

As I say, Hyperthreading definitely "works" on my i5 and did with 12.04 as well as 14.04. Whether it helps or hinders I have no idea! I do know that the current Hyperthreading technology has nothing, or very little, to do with the Hyperthrading of the old P4 CPUs and most of the comments I read on it when the processors first came out seem to assume they were the same beast. I also know on Doze systems having it enabled on an i7 gave massive performance boosts with audio software, whereas on the old P4 performance was better with HT disabled (at least initially.)

So can anybody point to any conclusive evidence that i-series processors benefit from having HT disabled on a Linux based DAW? Preferably benchmarks on a system installed with HT Enabled and Disabled using a recent kernel and system.

There are also other BIOS settings I would like some recommendation on how to set. Also how much difference does it make it functions are turned on in BIOS and then Disabled later? I would imaging the other way around would cause more difficulties (as maybe the relevant parts of the kernel wouldn't be installed?) but have definitely read recommendations to make sure to set up BIOS first.

The items in question are:
Intel SpeedStep
CPU Management
Intel Hyper-Threading (mentioned above.)

Also: Are there any good resources on setting up an Arch DAW system? I have been reading as much as possible on the Arch Wiki as I can while we have power and internet here (really not much just lately! About 2 hours the whole of today!!)

Some offline documentation would be very useful, so I can read when the internet is down!
http://archaudio.org seems to be dead in the water! Was it superseded?
Plus these couple of articles I found but admit yet to read as been concentrating on the general Wiki.
http://www.linux.com/learn/tutorials/607117-build-a-serious-multimedia-production-workstation-with-arch-linux
https://wiki.archlinux.org/index.php/Pro_Audio
Anything else you can point me to I would be very thankful. I believe Arch is the next step I wan to take. :)
Also starting to feel a little disenfranchised with XFCE. What are you guys running your Arch DAW with?

Thanks for any pointers. :)

[1] http://www.pcmag.com/article2/0,2817,2404675,00.asp

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Received on Fri Aug 29 04:15:02 2014