HT Cores and Physical Cores

[mukunda]

So from what I understand from reading here, an HT core is a physical core cut in half, but at low-load times it could offer much more power if the other corresponding HT core isn't doing much.

When renting a 6-core VDS, is it always using 6 physical cores shared with another customer? or can one customer achieve 3 full physical cores?

[kraze]

HT cores can be somewhat confusing at first but we talk a bit on how they work and their performance here.

http://www.nfoservers.com/forums/viewto ... =47&t=5099
http://www.nfoservers.com/forums/viewto ... =47&t=4940

You can think of an HT core being a real core split in half and that's probably the easiest way to look at it but the OS doesn't know that at all. To the OS it is a *true* core if you will.

[mukunda]

I'm still scratching my head about this

Say I have a 2-core VDS with 1 source server on it. Source servers are single-threaded, so if the cores were actual physical cores, the second core would obviously have no (or little) effect to the power of the server.

Now.. with these "HT cores" it seems like it would make sense that they could be servicing the same process while the other core is servicing another customer.

Does that make sense? Can two HT cores service the same process and increase the overall maximum power?

[kraze]

To the OS they're two different cores so technically they couldn't be servicing the same process. It is possible you could have two HT cores which are on the same physical core but even then, they're two different cores to the OS and any software you are running.

Now.. with these "HT cores" it seems like it would make sense that they could be servicing the same process while the other core is servicing another customer.

It is very possible that one HT core would be serving you while another HT core on the same physical core is serving someone else but you're not actually sharing resources since we are dedicating them to you.

The easiest thing you can do to help you understand it would be not to overthink it. If you start doing that you may just end up confusing yourself.

Try to think of something that has a core component but can do two things at once. Your hands may be a good example of this. One hand can be doing something while your other hand could be sitting there or it could also be doing something.

That may not be the best example but you see my point on how both hands can do something without causing you or your brain any trouble.