How does VB choose performance/efficient cores
How does VB choose performance/efficient cores
The next gen Intel CPU will have performance cores and efficient cores. When create VM with 4 core/thread, how does the VB choose among performance and efficient cores? Will it be fixed at VM creation, or can it dynamically switch between the two types of cores?
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Re: How does VB choose performance/efficient cores
I personally have never heard of this. If the "next-gen" means these devices are not out yet, it could be the devs haven't had a chance to test. We'll have to wait until this concept becomes mainstream to see how the devs will set Virtualbox to handle it.
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Re: How does VB choose performance/efficient cores
You can read about the basics in Intel's Alder Lake Combines 'Performance' and 'Efficiency' CPU Cores on One Chip.scottgus1 wrote:I personally have never heard of this.
To give you an example from today, VirtualBox creates 42-ish threads for a VM with 2 vCPUs, and lets the host OS decide on which physical CPU cores/threads to run them. As far as I understand the known details of the Intel Thread Director (Intel Architecture Day 2021: Alder Lake, Golden Cove, and Gracemont Detailed), the physical CPU and the host OS will decide the core/thread selection themselves.reader wrote:When create VM with 4 core/thread, how does the VB choose among performance and efficient cores? Will it be fixed at VM creation, or can it dynamically switch between the two types of cores?
Re: How does VB choose performance/efficient cores
Does anyone have a new perspective on this, now that 12700 has been out for a while and 12900 is coming out? Trying to decide on intel or AMD for a box that will mostly be for VMs and sometimes gaming. The E cores run slower than the P cores, wondering what the overall impact is on VMs with VBox. Will I see much difference between AMD (12 cores)/24 threads vs Intel (8P+8E cores)/24 threads when running several VMs at once (database server, web server, etc)?
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Re: How does VB choose performance/efficient cores
I can't see that changing. I would not expect VirtualBox (or any other app) to get involved at that level. CPU queues and priority scheduling are pretty low-level OS stuff.fth0 wrote: To give you an example from today, VirtualBox creates 42-ish threads for a VM with 2 vCPUs, and lets the host OS decide on which physical CPU cores/threads to run them. As far as I understand the known details of the Intel Thread Director (Intel Architecture Day 2021: Alder Lake, Golden Cove, and Gracemont Detailed), the physical CPU and the host OS will decide the core/thread selection themselves.
Bill