Is hyper threading built into each core or is it for the entire chip?

[Maximilian]

E.g. could you have say a 3770k with 4 cores and only 2 of the cores have HT, making for a total of 6 threads, or is it something that has to work for the entire chip or not at all?

 

[BrightCandle]

Intel could in theory make a chip with only 2 hyper threaded cores and 2 none hyper threaded cores. Not sure the operating system would current understand it but its a per core capability not a chip wide thing (as far as I know).

They do not make such a chip.

 

[ShintaiDK]

Its per core. But mixing cores with and without HT doesnt really make sense.

 

[NTMBK]

If I remember correctly, to make a core hyperthreading capable you need to duplicate the registers and make the front end capable of accepting two instruction streams. (Someone who knows more [like IDC ] feel free to correct me.) So I would assume it is per-core.

 

[Idontcare]

E.g. could you have say a 3770k with 4 cores and only 2 of the cores have HT, making for a total of 6 threads, or is it something that has to work for the entire chip or not at all?

You can effectively accomplish this with software by manipulating the "core parking" parameters in windows itself along with setting thread affinity of course to avoid two of the virtual cores.

But why would you want to do this?

 

[Exophase]

Its per core. But mixing cores with and without HT doesnt really make sense.

Doesn't make any less sense than fusing off HT entirely. If Intel wanted more bin granularity they could do it, especially if you had chips with defective HT in some cores only.

But Intel over-segments as it is :| That, and a 6T/4C chip might be too close to an 8T/4C chip in real world usefulness..

 

[Charles Kozierok]

Yeah, you could do it. But HT doesn't take a lot of die real estate -- that's one of its selling points -- and my guess is there probably aren't very many chips that test properly except for HT capability in some of the cores.

 

[ShintaiDK]

Doesn't make any less sense than fusing off HT entirely. If Intel wanted more bin granularity they could do it, especially if you had chips with defective HT in some cores only.

But Intel over-segments as it is :| That, and a 6T/4C chip might be too close to an 8T/4C chip in real world usefulness..

Thats your claim.

You say Intel oversegments, yet you wish more segmentation?

 

[Charles Kozierok]

I think he was saying that they could do it, but he hopes they won't.

 

[AtenRa]

E.g. could you have say a 3770k with 4 cores and only 2 of the cores have HT, making for a total of 6 threads, or is it something that has to work for the entire chip or not at all?

HT is per Core, old and current motherboards only have the ability to Enable/Disable the HT in BIOS for all Cores. That means you cannot enable the HT only for the two cores, once enabled it turns on for all four cores.

Theoretically, Intel could disable HT only in two of the four Cores and have a 6 threads CPU.

 

[Exophase]

Thats your claim.

You say Intel oversegments, yet you wish more segmentation?

I'm pretty sure I'm not the only person who thinks that Intel over-segments and offers weird segment exclusivity (even the Intel engineer who did the AMA agreed with this!), and no I didn't say I hope they offer more.

 

[LOL_Wut_Axel]

I'm pretty sure I'm not the only person who thinks that Intel over-segments and offers weird segment exclusivity (even the Intel engineer who did the AMA agreed with this!), and no I didn't say I hope they offer more.

If you want the best sometimes you gotta pay up. You could make an argument both in favor of AMD or Intel here. For example, with the i7-3770K you only get around 5-10% more multi-threaded performance overall than the FX-8350, but you get massively higher single-threaded performance and half the power consumption and heat output. For those benefits Intel makes you pay $120 more, which many would say is fair. At the same time, if you're looking for bang-for-buck in multi-threaded programs, the FX-8350 is an excellent choice.

You could also make arguments in favor of each platform itself as well. Intel changes sockets more, but that allows them to bring constant improvement to their line. They change chipsets often, but that means you're guaranteed compatibility with the CPU you bought (with most 900-series chipset boards you have to update your BIOS to get support for Piledriver, while you don't need to do that for 7-series chipset boards with Sandy/Ivy Bridge). But AMD having less socket changes allows you to run anything from an Athlon II to a Piledriver FX in the same board.

I personally just upgraded from my 2600K because my 3770K only cost me $105.

 

[Exophase]

I'm not saying all segmentation is bad. I'm definitely not in the camp that thinks that a CPU manufacturer is ripping you off by fusing off a working feature to artificially create segmentation. I get that driving higher capability chips at higher prices allows them to reduce the cost of lower capability chips. But it sucks when you can't even get all the features and have to accept losing some. Not that I personally care about any of these features, mind you.

Where did you buy a 3770K for $105? I mean personally I would not upgrade my i5-2500K to an i5-3550K for anything more than a few dollars because the improvement is so small, but I might consider going for the extra threads..

 

[Idontcare]

I personally just upgraded from my 2600K because my 3770K only cost me $105.

You didn't have to pay the $18 S/H fee or sales tax for the retail edge deal? Mine cost me nearly $130 when it was all said and done.

Where did you buy a 3770K for $105? I mean personally I would not upgrade my i5-2500K to an i5-3550K for anything more than a few dollars because the improvement is so small, but I might consider going for the extra threads..

Its the retail edge deal.

 

[Exophase]

Its the retail edge deal.

Pfeh.. if getting these deals means working retail then I'm happy to miss them

 

[Idontcare]

Pfeh.. if getting these deals means working retail then I'm happy to miss them

It can also mean that you happen to know someone who does, and they are willing to help a brother out :sneaky:

 

[LOL_Wut_Axel]

You didn't have to pay the $18 S/H fee or sales tax for the retail edge deal? Mine cost me nearly $130 when it was all said and done.



Its the retail edge deal.

Yeah, shipping and handling cost me $15.50 but I didn't factor that in since it's out of our control. Final price was $125.50 for me. Not too shabby.

Pfeh.. if getting these deals means working retail then I'm happy to miss them

It depends on where you work, who you work with and the pay, and in my case I can't complain about any of those.