CPU Cores or Hyperthreads?

February 8, 2015 6.8k views

When the Pricing page lists "2 core processor" what exactly does that mean? Does that mean I get two logical cores out of an eight core processor? Does that mean I get a single logical core that has two hyperthreads?

3 comments
  • I would also like to know this.. Hope someone from DO staff clarifies this..

  • Currently the most popular question, asked over a year ago... no answer?
    Even if it seems a simple question with an answer that could be inferred from the docs and FAQ. A good answer could address the underlying concerns, for example, linking to a tutorial on how to schedule your processes or force affinity for best performance on a mid-range droplet.

  • Apologies! Disregard previous comment please. I'm not sure if it was sleep deprivation or a browser issue that influenced the failure see the answers below; but either way I'm wearing the shame hat for today.

2 Answers

I would say that you neither get "physical" nor "hyper-threaded" cores.
Digital Ocean uses KVM virtualization. KVM runs between your hardware and each of the virtualized machines (also called VMs, Droplets, etc).
Each of the visualised cores "equals" a CPU core. When a vCore (virtualized Core) requires processing time a process called system scheduler will point the vCore request to a free physical Core.
Note that the Virtual Machine itself is "unaware" about this and any of your vCores can end up using cycles of any of the free physical CPUs.

Further, you do not get 2 cores dedicated to you, but actually your virtual machine is not underpowered, as the vCores will use processing time from the physical CPU only when they need it.

Just to add to the answer @Viko provided, here's a dmidecode report:

dmidecode -t processor
# dmidecode 2.12
SMBIOS 2.4 present.

Handle 0x0401, DMI type 4, 32 bytes
Processor Information
        Socket Designation: CPU 1
        Type: Central Processor
        Family: Other
        Manufacturer: Bochs
        ID: E4 06 03 00 FF FB 8B 0F
        Version: Not Specified
        Voltage: Unknown
        External Clock: Unknown
        Max Speed: 2000 MHz
        Current Speed: 2000 MHz
        Status: Populated, Enabled
        Upgrade: Other
        L1 Cache Handle: Not Provided
        L2 Cache Handle: Not Provided
        L3 Cache Handle: Not Provided

Handle 0x0402, DMI type 4, 32 bytes
Processor Information
        Socket Designation: CPU 2
        Type: Central Processor
        Family: Other
        Manufacturer: Bochs
        ID: E4 06 03 00 FF FB 8B 0F
        Version: Not Specified
        Voltage: Unknown
        External Clock: Unknown
        Max Speed: 2000 MHz
        Current Speed: 2000 MHz
        Status: Populated, Enabled
        Upgrade: Other
        L1 Cache Handle: Not Provided
        L2 Cache Handle: Not Provided
        L3 Cache Handle: Not Provided

Also, here's the /proc/cpuinfo details:

processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 62
model name      : Intel(R) Xeon(R) CPU E5-2630L v2 @ 2.40GHz
stepping        : 4
microcode       : 1
cpu MHz         : 2399.998
cache size      : 15360 KB
physical id     : 0
siblings        : 1
core id         : 0
cpu cores       : 1
apicid          : 0
initial apicid  : 0
fpu             : yes
fpu_exception   : yes
cpuid level     : 13
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon rep_good unfair_spinlock pni pclmulqdq vmx ssse3 cx16 pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm xsaveopt vnmi ept fsgsbase smep erms
bogomips        : 4799.99
clflush size    : 64
cache_alignment : 64
address sizes   : 40 bits physical, 48 bits virtual
power management:

processor       : 1
vendor_id       : GenuineIntel
cpu family      : 6
model           : 62
model name      : Intel(R) Xeon(R) CPU E5-2630L v2 @ 2.40GHz
stepping        : 4
microcode       : 1
cpu MHz         : 2399.998
cache size      : 15360 KB
physical id     : 1
siblings        : 1
core id         : 0
cpu cores       : 1
apicid          : 1
initial apicid  : 1
fpu             : yes
fpu_exception   : yes
cpuid level     : 13
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon rep_good unfair_spinlock pni pclmulqdq vmx ssse3 cx16 pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm xsaveopt vnmi ept fsgsbase smep erms
bogomips        : 4799.99
clflush size    : 64
cache_alignment : 64
address sizes   : 40 bits physical, 48 bits virtual
power management:

Now, the details on the processor it reports:

intel doc sheet screenshot

Now, as you can see, this CPU is fully capable of Hyperthreading, so yes, as it's been said. It's not regular CPUs, so you're trying to compare apples to oranges.

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