Number of processor cores confusion

[Robert Heller]

At Mon, 09 Nov 2020 18:28:33 +0100 "Ubuntu user technical support,  not for general discussions" <ubuntu-users at lists.ubuntu.com> wrote:

> 
> Hi!
> 
> When I bought my PC a few months ago, I was told that it has 8 processor
> cores. But the gnome system monitor display 16 cores. So does /proc/cpuinfo.
> The inxi tool reports *both*:
> 
> desktop ~ $ inxi --cpu
> CPU:
>   Topology: 8-Core model: AMD Ryzen 7 2700X bits: 64 type: MT MCP 
>   L2 cache: 4096 KiB 
>   Speed: 1887 MHz min/max: 2200/3700 MHz 
>   Core speeds (MHz): 1: 1891 2: 1991 
>   3: 1896 4: 2063 5: 2058 6: 2187 7: 2046 8: 2193 9: 2190 10: 1889 11: 1888 
>   12: 2096 13: 1887 14: 2204 15: 2189 16: 1907 
> 
> WTF?!

Intel developed a "hack" where one "core" had some parts of the core elements
duplicated, allowing a level of multiprocessing. These are "multi-threaded
cores". Linux shows these cores as two cores (each). I did not know that AMD
also implemented this hack. It is a bit of a hack, since the multi-threading 
does not allow for full SMP.

> 
> Cheers,
> Volker
> 

-- 
Robert Heller             -- Cell: 413-658-7953 GV: 978-633-5364
Deepwoods Software        -- Custom Software Services
http://www.deepsoft.com/  -- Linux Administration Services
heller at deepsoft.com       -- Webhosting Services