T do believe I disabled HT(hyper-threading) on my iMac using terminal accidentally.
Is there a terminal command that will enable HT for the 2015 5K iMac with this i5 processor?
Thanks !
macOS High Sierra (10.13.5)
The I5 processes is not capable of hyperthreading. The I7 processor is required to get hyperthreading.
The I5 processes is not capable of hyperthreading. The I7 processor is required to get hyperthreading.
According to Intel the i5 processor does not use hyper threading (HTT):
https://www.intel.com/content/www/us/en/support/articles/000005505/processors.ht ml
I'll try again. i5 processors are not capable of HTT. Read the charts at the link I provided. The charts clearly show how many Cores and how many threads each processor runs. A 4 Core processor running 4 threads is not using HTT. A 4 Core processor running 8 threads is using HTT. The charts clearly show this.
With respect to older Pentium and other intel processors some of them started using HTT technology around 2002 but the i5 processor abandoned HTT which was reintroduced with the i7 processor.
An i5 processor is not capable of HTT.
Sure looks like you are right on!
I checked the rest of my computers (all running on a distributed grid system, searching for cancer cure markers)
My 2015 5K iMac has a core i5 and reports 4 jobs running at the same time.
Another iMac, 2011, also an i5, also reports 4 jobs.
A 2010 Mac Pro (last of the towers)has a quad core Xeon proc. and reports 8 jobs.
Another Mac Pro, 2008, also has 2 ea Zeon processors, but too early for Hyper Threading? reports 8 jobs.
And the last is a PC with a water cooled i7 4790K (4.3 Ghz) reports 8 jobs.
Many thanks for clearing this up!
Tom
Thanks. A question: Does the presence of HTT in the feature list indicate HT capability?
If so, I am at a loss as to why the process count (jobs) is not higher for my computers !
Am reasonably sure that the dual processor (2008) does not do HT?
Appreciate any further info.
Sorry, but I did not address all of your questions above.
Yes, I am talking about the physical cores of each 4 core cpu. I had expected to see 4 processes+1 or 2 (?) processes for each logical core (HT) for a total of 8 processes for each 4 core cpu. Is this correct?
These processes are obtained via Boinc manager and World Community Grid, crunching numbers, looking for cancer markers. (Beats SETI)
The subject of this thread is HTT and an i5 processor. Why are you now asking about an i7? Is this a new question, a new computer, ...? Why would HTT not be working in an i7? i7s use HHT according to the same intel link I posted previously. If the i7 is 4 Core and it is running 8 processes it is hyper threading.
Sorry for any confusion. My original question mentioned both the i5 and a PC with an i7.
There are 5 computer in question. All Macs with an i5, and one PC with the i7.
All seem to show a max of 8 processes, with the exception of 2 iMacs, (i5) which show only 4 processes.
How many processes should a CPU with HT actually show???
I now guess that my original question should have been for a better explanation of just what hyper-threading does, and what to expect from that process? AND how to enable it for both the i5 and i7 CPu's.
Thanks
"HTT" in the features list would indicate that Hyper-Threading Technology is an available feature. The other person who replied indicated that it should not be listed in your features list though and the only way to tell would be to check in the Terminal or to look up your specific CPU model and then go see what the manual from Intel says. These are usually 1000 page documents so it should include some sort of explanation as to what it can and can't do and how it's all been branded. Multithreading is the generic term for what Intel has branded Hyper-Threading Technology and their various implentations of it
I'm no expert on processors but the 1000 page manual would probably cover this topic. Never heard of the software you're using but maybe contact their support/forum. Apple Communities is supposedly plain old users and one can't expect detailed, customized responses to questions is what I've noticed from my experience here.
I'd recommend that on your Mac computers you use Apple's Activity Monitor app to see all of the processes running. It's under Applications > Utilities > Activity Monitor. I know I have an i7 but as you can see there are a lot more than 8 processes running and there are surely several hundred on each of your computers as well.
Another question for you: How many (total) processes should an i5 4 core processor handle with HT?
Thanks !
Bob:
I just checked the PC with an i7 cpu running at 4 Ghz. It also is showing only 8 processes !
I know this cpu should be using HT.
Any suggestions?
Thank you, Bob, from a genuine Newbie.
Color me gone. I am done (for now). LOL
I'm confused what you're talking about really. Maybe I missed something, but your i5 should be capable and using hyper threading. Are you referring to each physical cores of the CPU having an additional logical core? And by jobs do you mean processes? Because there should definitely be more than 8 processes running on all of your computers at all times.
If you want to check if your processor is capable of hyper threading you can use sysctl in your Terminal
sysctl machdep.cpu.features
HTT is the abbreviation for it. This is what my laptop shows using that command:
sysctl machdep.cpu.features
machdep.cpu.features: FPU VME DE PSE TSC MSR PAE MCE CX8 APIC SEP MTRR PGE MCA CMOV PAT PSE36 CLFSH DS ACPI MMX FXSR SSE SSE2 SS HTT TM PBE SSE3 PCLMULQDQ DTES64 MON DSCPL VMX SMX EST TM2 SSSE3 FMA CX16 TPR PDCM SSE4.1 SSE4.2 x2APIC MOVBE POPCNT AES PCID XSAVE OSXSAVE SEGLIM64 TSCTMR AVX1.0 RDRAND F16C
This will show you other details about your CPU:
sysctl -a | grep -i cpu
How can I enable hyper-threading on my 2015 i5 iMac?
