Will a VM always be slower ?

[pcslookout]

Than a real machine.

 

[JackMDS]

Yeah it will.

That said, if you build a really super fast computer (fast CPU with a lot of Memory) it might be that the ""Slowed"" VM would be fast enough to do what you need it to do.

 

[Rifter]

Yes, this is why servers are overbuiult for what you need vs a standalone OS with no VM's.

 

[mv2devnull]

Logically, there is always some overhead from the host being between the metal and the VM. That, however, is not important. Usain Bolt has been fast on 100m sprint three Olympic Games in a row. Somebody else was always slower. Nevertheless, those somebody elses were still incredibly fast.

The real question: Is a VM significantly slower than the host and is the loss of speed an unacceptable tradeoff despite the gained benefits?

IMHO no. VM is fast enough* and the things that the virtualization allows are worth the sacrifice.


*There are always exceptions to everything.

 

[pcslookout]

Thank you!

 

[mxnerd]

The reality is you have to have fast CPU (at least 4 cores, forget about any 2-core processors) and fast drive for the VM, SSD preferred.

If you use HDD, VM performance will be greatly impacted.

 

[Rifter]

If you use HDD, VM performance will be greatly impacted.

This is like the understatement of the century.

 

[TheELF]

While a VM will be always slower ,as a whole machine, it still can run some stuff at the same speed as the host, if the program can run on the CPU only for example than there is zero difference nowadays due to the virtualization within the chips themselves.

 

[Red Squirrel]

There will always be some sort of overhead, though they can still be very fast especially on fast hardware. Multi core is key. I'm thinking a Ryzen threadripper based machine would make quite a respectful VM server.

Where VMs don't do well is graphics acceleration stuff like games. Most games won't run, or even start, in a VM.

 

[Ketchup]

Than a real machine.

In what way? A VM is separate from the host machine for a reason, but provided enough memory and considering a system that allows a VM to utilize all features of the CPU being used, the only major loss the VMs still see is on the 3D graphics side. However, most VMs are not used in a way where that is a concern. I have 3 VMs that I can run at the same time all on separate VPNs doing work simultaneously within those connections, and my desktop is still free to do whatever. To me, that shows a tremendous speed advantagetage over a non-vm system, assuming multiple tasks from different connections was required (and this is just one of dozens of examples).

 

[grimham]

I think he was just asking "apples to apples" would a VM be slower than - as he put it "a real machine". The answer is always "Yes".