Questions tagged [hyperthreading]
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29 questions
8
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Kernel shows SMT as "notsupported" for AMD 3970x
I have a Threadripper 3970x that has 32 cores and 64 threads. I installed Linux and the kernel shows SMT as being "notsupported":
root@services:~# cat /sys/devices/system/cpu/smt/control
...
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3
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2
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808
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Why does higher CPU-usage slow down a task?
I am using whisper.cpp to transcribe some sound files. It is a very CPU heavy process so I try to find some optimal settings and therefore I have done some tests with the thread setting (-t) but the ...
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3
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0
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353
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How do I flag a process to avoid hyperthreading (SMT)?
Suppose I have an 18 core CPU with SMT enabled, and there are 18 long runnning processes, all using ~100% of a thread. If I start a 19th process, the kernel will schedule it to run on one of the cores,...
- 141
0
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1
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Linux Mint showing 1 thread per core in a 4 thread/core cpu
I have a Ryzen 3 3200g and, when I do lscpu in a Linux Mint 20.1 Cinnamon OS terminal, the output says that I only have 1 thread per core. The Windows system's info accurately recognizes that my CPU ...
- 103
1
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1
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In Solaris box how do we check if hyper-threading/multi-threading is enabled or not using command?
In Solaris, how we can find the status or check hyper-threading or multi-threading is enabled or not using commands?
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3
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1
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873
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How to reliably tell from Linux whether the CPU supports Hyperthreading, even if Hyperthreading is disabled?
The following is what I am doing to tell whether a processor does support HT or not, regardless of whether it is enabled or disabled:
# dmidecode -t processor | grep "Hardware Thread" | wc -l
If ...
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3
votes
1
answer
155
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CMOS occasionally resets hyperthreading. Can I force hyperthreading on using Linux kernel?
I have some i7-4700EQ based embedded server systems that require hyperthreading. All is good except that, on rare occasions, the hyperthreading flag in CMOS gets set to disabled. While the hardware ...
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2
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0
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2k
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How to tell if the CPU supports hyper threading
I know it should be a simple matter of grep -wl ht /proc/cpuinfo but that's not always accurate.
I have an i5-7440HQ CPU which doesn't support hyper-threading (Intel, WikiPedia, and my BIOS agree on ...
- 383
-1
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1
answer
192
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Are there UNIX variants or other OS which make user level threads visible to OS kernel? [closed]
Are there UNIX variants or other OS which make user level threads visible to OS kernel ?
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11
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1
answer
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What does "cpu MHz" field mean in the /proc/cpuinfo of a hyper-threading cpu?
The CPU is a [email protected]. It has 4 cores and each core has 2 threads. Here is the dmidecode output:
# dmidecode -t 4
# dmidecode 2.9
SMBIOS 2.7 present.
Handle 0x0042, DMI type 4, 42 bytes
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- 263
0
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2
answers
513
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Plain installation vs Virtual machines - what is better for multicore? [closed]
We've currently bought a new server, with 64 GB of RAM and 8 cores with hyperthreading support. We are going to build a system using:
nginx.
apache.
mysql.
php
So, the question is about performance: ...
- 109
1
vote
1
answer
4k
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Benefits of hyperthreading for an Oracle database
I'm running Oracle 10 on a blade450 g6. I have hyper-threading turned on but I have heard several people say that Oracle databases don't play well with it. Are there specific performance or ...
- 11
3
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1
answer
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Hyperthread and processors Clock, Size, and Capacity
When I enable hyperthreading, CPU size and capacity decrease to about half the non-hyperthreaded value. Since most of my processes use only two cores, should I disable hyperthreading?
lshw -C ...
7
votes
1
answer
5k
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Should I disable hyperthreading when concerned about performance of single-threaded applications?
I use a i5-2410M processor, which is setup to do hyperthreading by default on my laptop. Considering that this is a 2-core processor, this means it can do 4 threads at a time. This also means that ...
- 67.7k
13
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3
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4k
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How can I have 400% CPU occupied on 2 cores
I understand that Σ(%CPU) ≤ logicalcores*(1+ε) (where ε is measure and rounding error). But, how can I have on a 2 core system 2 different processes, each taking 200% of CPU (as measured by htop)?
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