I turned it off in Bios. But if I may ask why not buy i5 processor and save some money. From what I know almost the only difference between them is that i7 has hyperthreading. On 22 בDec 2013 08:34, "david" wrote: Setting up my shiny new laptop. i7 processor with hyperthreading. How to turn HT off?

On Sat, 21 Dec 2013, david wrote: In linux each hyperthread is treated as another core. So if you have 4 cores, it will look like 8 with hyperthreading on. Every second cpu that linux sees is a hyperthread. so you only want cpu 0,2,4,and 6. There is a kernel command line option to have the kernel ignore some cpus, get it to ignore cpu 1,3,5 and 7. I seem to be off line right now so I can't look it up. Ah, back up. isolcpus= cpu_number[, cpu_number,...] The blurb for that: "Remove the specified CPUs, as defined by the cpu_number values, from the general kernel SMP balancing and scheduler algroithms. The only way to move a process onto or off an "isolated" CPU is via the CPU affinity syscalls. cpu_number begins at 0, so the maximum value is 1 less than the number of CPUs on the system. This option is the preferred way to isolate CPUs. The alternative, manually setting the CPU mask of all tasks in the system, can cause problems and suboptimal load balancer performance." The place to add this to your system (if you don't want enter it every time you boot) is in GRUBs config. The best place to do this varies with the ditro. For example, I have found the best place to do this on a Ubuntu system is in /etc/default/grub.d/ as it does not interfere with upgrades. The place you will see mentioned more often is a file called /etc/default/grub Look for a line like GRUB_CMDLINE_LINUX="" and edit it (as root of course) to: GRUB_CMDLINE_LINUX="isolcpus= 1,3,5,7" If you have more than 4 cores(6 or 8), I do not know if cpus higher than 9 are in hex or dec. If you wish to have grub menu options to boot either way.... I would guess it is time to learn more about GRUB :) It is easy to add menu items on a static system, but gets much harder on a system with lots of updates. Hmm, there seem to be a lot of irq options too. I wonder if they would be able to force better irq assignment within the system. I know telling the bios not to select irqs for USB gives better irq layout for me. Anyway, the list of kernel options I based this on is from: http://oreilly.com/linux/excerpts/9780596100797/kernel-boot-command-line-pa… -- Len Ovens www.ovenwerks.net

would do the trick too but on my own system I still can't go lower than -p128 so hopefully the isolcpus parameter improves stability.

Hi Jeremy! My MIDI interface is an M-Audio MIDISPORT Uno. Unfortunately the only sound device I have available at this time is the built-in on-board sound. Alsamixer reports it as "card: HDA Intel PCH, Chip: Realtech ALC892." Apparently my Rolland OctaCapture isn't supported at present, or I would be using that.

Currently my Jack-2 settings are: –realtime –timeout=4500 –no-m_lock -d alsa –device=HW:0 –rate=44100 –period=256 –dither=shaped midi=none. I haven't had a chance to try larger latency yet, but I could do that once I'm playing back sequences.

Is there any reason to do anything with "nice" on either A2J or anything else? I think I have most of the recommended optimizations for audio done, except for the rt kernel, but just wondered about nice, since I've seen it used, but don't see any recommendations about it.

The uname -a shows: Linux StudioLinux 3.5.0-42-generic #65~precise1-Ubuntu SMP Wed Oct 2 20:57:18 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux Studio is just its name reflecting location, it isn't a special blend of Linux.

Thanks much for your help. Kevin