AMD developing reverse hyperthreading? - bit-tech.net Forums

WilHarris · 17th Apr 2006, 12:49

http://www.bit-tech.net/news/2006/04...yperthreading/

Yotsuba · 17th Apr 2006, 12:52

O_O

Imagine the preformance with the X2 5000+!

Or dual Opterons..

Glider · 17th Apr 2006, 13:10

Seems a bit against the flow... Everyone is going dual... But in single threaded app's, it would be awsome. Just some on the fly on/off switching would be needed I guess.

So nice idea, but needs a lot of perfecting and fine tuning. But I am confident the people at AMD will pull this off

genesisofthesith · 17th Apr 2006, 13:17

Intel have been working on speculative threading for sometime, so you have to believe that there are serious issues in implementing this - after all how many tasks would truly be able to be split up? Is it a wste of die space? intel worked on speculative threading since the p4 introduced hyperthreading, and its still nowhere in sight. It may be an idea that in theory sounds good, but in practice yields few benefits. Why add x ammount of transistors to yield a small performance increase in a very limited number of tasks where you could use that same transistor count to improve performance accross the board (wider execution paths, more cache etc.)

Krikkit · 17th Apr 2006, 13:32

Quote:

Originally Posted by genesisofthesith

Why add x ammount of transistors to yield a small performance increase in a very limited number of tasks where you could use that same transistor count to improve performance accross the board (wider execution paths, more cache etc.)

Because it shouldn't be a small performance increase having 2 cores work as 1, it'll be at least 50% boost imo, and having a small execution set add-in for doing that in single-threaded apps would be a great idea, as there are still a hell of a lot of single-threaded apps which need some serious crunching time.

genesisofthesith · 17th Apr 2006, 13:46

migrating single threaded aps to multi threaded where possible should be done by the developers, on a thread level judging what threads can be split (where there are no dependencies etc.) is very difficult. Few tasks could be split, and even those that do get split may face dependency problems and would be a waste of cpu time. The code should be made as parallel as possible, and whilst some single threaded code may be able to be split and see a benefit, most single threaded code would see no performance improvement and possibly a penalty. speculative threading is a stop gap until code is properly optimised, and I just think that instead of spending money implementing it, everyone would be better served if this time and effort is put into actually threading and optimising the code where possible.

Drexial · 17th Apr 2006, 14:32

Why do people keep comparing the Conroe to the AM2.... Conroe is a complete architecture revamp. AM2 is just a socket change, why do people keep thinking that just adding in DDR2 suport for curent generation AMD processors is going to do anythign for performence, when the architecture of the chip isnt designed to take advantage of it.

as far as the "anti-hyperthreading" i agree with whats been said above. in order to make it useful it should be able to switch on the fly, because onlder games will see a benifit. but all the anticipated PC games are going to want to use DUal cores. however, switching on the fly will be pretty useless unless they develop a processor for the processor to calculate which games are using one, or two processors. but it doesnt seem liek somthing that would be able to be done on a harware level. and on a software level. it would be alot better to use the Dual cores as dual cores and not as a single.

Fusen · 17th Apr 2006, 14:40

you need quad cores where you can switch on anti hyperthreading to make it a set of 2 cores running off all 4 ;D

Aphex_ · 17th Apr 2006, 14:44

surely it can't be too big an expense in terms of die space to have the processor be able to split a thread in two, with shared cache it shouldn't be too big a leap surely? esp with the processors having hyper transport to communicate with, 50% increase in performance would be 25% better than conroe atm... doesnt take a genius to see it has its benefits.

It would also make dual core more attractive in general, just imagine an fx-60 with this, it rules the roost as it is, but with another 50%... wow!! even if it was only 25% it would still be amazing.

splitting threads in the processor takes some of the onus off of programmers, esp with regard to companies that don't have big budgets.

sounds like a really good idea, and with quad core and upwards it really does make a hell of a lot of sense. i mean even if u had one core dedicated to the calculations required for this out of 4 the improvements in single threaded would be immense!!

huzzah for amd!!!

scq · 17th Apr 2006, 15:00

Quote:

Originally Posted by Glider

Seems a bit against the flow... Everyone is going dual... But in single threaded app's, it would be awsome. Just some on the fly on/off switching would be needed I guess.

So nice idea, but needs a lot of perfecting and fine tuning. But I am confident the people at AMD will pull this off

I would believe that AMD would try to make the processor only switch to anti-HT, when single threaded operations are made. However, this technology would probably die off once most, if not all programs and games are rewritten or published with multi-threaded support.

However, like 64-bit, I'm guessing that actual consumer adoption of it, will probably be slow (maybe a bit faster, but still slow). Everyone will have the hardware for dual core, but hardware is useless without the proper software to back it up.

Ramble · 17th Apr 2006, 15:01

Super Pi times of 15-20 seconds?

I sure hope so.

LAGMonkey · 17th Apr 2006, 15:20

I like the idea in theory. As its been pointed out, many apps are single threaded and some will prob never be multi-thread as they work better with one. If you can switch an AMD x2 between multi and single-threads then it would be a HUGE performance it. You'd get the best of both worlds assuming its implimented correctly.
And once all the software has migrated to multi-thread then you can just stop the switching.
As many have pointed out, hardware is useless without the proper hardware. But on the other hand, unless the hardware is out then there isnt any point in software.

Chicken and the egg it seems.

Bindibadgi · 17th Apr 2006, 15:41

Quote:

Originally Posted by Ramble

Super Pi times of 15-20 seconds?

I sure hope so.

Yea cause I spend ALL day just using Super Pi. Infact, I have no other programs installed.

:P

Ramble · 17th Apr 2006, 15:53

Quote:

Originally Posted by Bindibadgi

Yea cause I spend ALL day just using Super Pi. Infact, I have no other programs installed.

:P

Hey, it's a good thing for all the Pi lovers out there.

wharrad · 17th Apr 2006, 16:25

Sounds likes a good idea, it really does. However, got some issues regarding 'on the fly' changing between splitting the application up.

Do you guys think this will be like HT where you can see two procs in Task Manager? It just seems more likely that you have to enable it in the BIOS and then you see a single core in windows (or linux or whatever).

Would be a good way to keep tabs on Intel until they get a new architecture involved.

(sorry about the spam...)

Quote:

Ramble - Hey, it's a good thing for all the Pi lovers out there.

Weebl and Bob will be happy then!!!

Quote:

Drexial - onlder

Despite it being a typo, it's the best spelling of 'only older' I've ever seen!!

Kipman725 · 17th Apr 2006, 16:53

Some AAPS are imposible or have very little performance advantage from multithreading. This sounds awsome if this works well then AMD will just trample all.

_Kat_ · 17th Apr 2006, 17:01

I'd stick to dual and quad cores... I just don't see the point of a 10 Ghz core which actually excists out of 2 or 3 or 4 cores when you have 4 cores. 4 cores that could be split with hyper treading and then do 8 different things at the same time instead of an extremely fast single core tht does 1 thing very fast. I say 8 different things at the same time is better then 1 thing very fast.

Kaze22 · 17th Apr 2006, 17:25

Quote:

Originally Posted by _Kat_

I'd stick to dual and quad cores... I just don't see the point of a 10 Ghz core which actually excists out of 2 or 3 or 4 cores when you have 4 cores. 4 cores that could be split with hyper treading and then do 8 different things at the same time instead of an extremely fast single core tht does 1 thing very fast. I say 8 different things at the same time is better then 1 thing very fast.

Wow the brilliant explanation we were all waiting for, thank you for enlightening us all.

Great job Einstein

Ta10n · 17th Apr 2006, 17:44

I think this is a great idea. I've been wondering why they haven't figured out how to use many cores or processors as one. Mad props to AMD on this one. Not only will this make ALL existing programs faster but programers don't have to program for more than one core, saving time and money.

Glider · 17th Apr 2006, 17:49

Quote:

Originally Posted by _Kat_

I'd stick to dual and quad cores... I just don't see the point of a 10 Ghz core which actually excists out of 2 or 3 or 4 cores when you have 4 cores. 4 cores that could be split with hyper treading and then do 8 different things at the same time instead of an extremely fast single core tht does 1 thing very fast. I say 8 different things at the same time is better then 1 thing very fast.

Is it me, or is there just so much not right with this?

Unless you only need to do 1 thing of course, then you'd have a quad system, working at 1/8th of his power.

17th Apr 2006, 12:49	#1
WilHarris Just another nobody Join Date: Jun 2001 Location: Oxford Posts: 2,671	AMD developing reverse hyperthreading? http://www.bit-tech.net/news/2006/04...yperthreading/

17th Apr 2006, 13:10	#3
Glider /dev/null Join Date: Aug 2005 Location: Belgium Posts: 4,102	Seems a bit against the flow... Everyone is going dual... But in single threaded app's, it would be awsome. Just some on the fly on/off switching would be needed I guess. So nice idea, but needs a lot of perfecting and fine tuning. But I am confident the people at AMD will pull this off __________________ There Are 10 Types Of People, Those Who Know Binary and Those Who Don't

17th Apr 2006, 15:01	#11
Ramble Ginger Nut Join Date: Dec 2005 Location: Exeter, Devon/Wantage, Oxfordshire Posts: 5,233	Super Pi times of 15-20 seconds? I sure hope so. __________________ Kirk, Spock, McCoy, and Ensign Ricky are beaming down to the planet. Guess who's not coming back.

17th Apr 2006, 15:20	#12
LAGMonkey Group 7 error Join Date: Aug 2004 Location: Canada/Saudi Posts: 1,449	I like the idea in theory. As its been pointed out, many apps are single threaded and some will prob never be multi-thread as they work better with one. If you can switch an AMD x2 between multi and single-threads then it would be a HUGE performance it. You'd get the best of both worlds assuming its implimented correctly. And once all the software has migrated to multi-thread then you can just stop the switching. As many have pointed out, hardware is useless without the proper hardware. But on the other hand, unless the hardware is out then there isnt any point in software. Chicken and the egg it seems. __________________ ---------------LAG out!--------------- http://www.ctrlaltdel-online.com 100% Brainless]

17th Apr 2006, 16:53	#16
Kipman725 When did I get a custom title!?! Join Date: Nov 2004 Location: UK Posts: 1,753	Some AAPS are imposible or have very little performance advantage from multithreading. This sounds awsome if this works well then AMD will just trample all. __________________ Sn45g game server mod My Electronics Site Hardware: 3400+ Sempr0n, 1GB RAM, 1.28TB local storage, x1950pro,Razer Viper,M$ comfort curve 2000,L70S + 17", Fujitsu 17" CRT Audio: HD-650's, PE congress amp, Sound Blaster AWE64, Soundblaster 24bit

17th Apr 2006, 12:52	#2
Yotsuba What's a Dremel? Join Date: Mar 2006 Location: Random Suburbs, Illinois Posts: 17	O_O Imagine the preformance with the X2 5000+! Or dual Opterons..

17th Apr 2006, 13:17	#4
genesisofthesith complete spanner Join Date: Dec 2004 Location: swansea, wales Posts: 533	Intel have been working on speculative threading for sometime, so you have to believe that there are serious issues in implementing this - after all how many tasks would truly be able to be split up? Is it a wste of die space? intel worked on speculative threading since the p4 introduced hyperthreading, and its still nowhere in sight. It may be an idea that in theory sounds good, but in practice yields few benefits. Why add x ammount of transistors to yield a small performance increase in a very limited number of tasks where you could use that same transistor count to improve performance accross the board (wider execution paths, more cache etc.)

17th Apr 2006, 13:46	#6
genesisofthesith complete spanner Join Date: Dec 2004 Location: swansea, wales Posts: 533	migrating single threaded aps to multi threaded where possible should be done by the developers, on a thread level judging what threads can be split (where there are no dependencies etc.) is very difficult. Few tasks could be split, and even those that do get split may face dependency problems and would be a waste of cpu time. The code should be made as parallel as possible, and whilst some single threaded code may be able to be split and see a benefit, most single threaded code would see no performance improvement and possibly a penalty. speculative threading is a stop gap until code is properly optimised, and I just think that instead of spending money implementing it, everyone would be better served if this time and effort is put into actually threading and optimising the code where possible.

17th Apr 2006, 14:32	#7
Drexial Supermodder Join Date: Jul 2005 Posts: 297	Why do people keep comparing the Conroe to the AM2.... Conroe is a complete architecture revamp. AM2 is just a socket change, why do people keep thinking that just adding in DDR2 suport for curent generation AMD processors is going to do anythign for performence, when the architecture of the chip isnt designed to take advantage of it. as far as the "anti-hyperthreading" i agree with whats been said above. in order to make it useful it should be able to switch on the fly, because onlder games will see a benifit. but all the anticipated PC games are going to want to use DUal cores. however, switching on the fly will be pretty useless unless they develop a processor for the processor to calculate which games are using one, or two processors. but it doesnt seem liek somthing that would be able to be done on a harware level. and on a software level. it would be alot better to use the Dual cores as dual cores and not as a single.

17th Apr 2006, 14:40	#8
Fusen Supermodder Join Date: Jan 2004 Location: Kent Uni Posts: 350	you need quad cores where you can switch on anti hyperthreading to make it a set of 2 cores running off all 4 ;D

17th Apr 2006, 14:44	#9
Aphex_ What's a Dremel? Join Date: Oct 2005 Location: Manchester, UK Posts: 19	surely it can't be too big an expense in terms of die space to have the processor be able to split a thread in two, with shared cache it shouldn't be too big a leap surely? esp with the processors having hyper transport to communicate with, 50% increase in performance would be 25% better than conroe atm... doesnt take a genius to see it has its benefits. It would also make dual core more attractive in general, just imagine an fx-60 with this, it rules the roost as it is, but with another 50%... wow!! even if it was only 25% it would still be amazing. splitting threads in the processor takes some of the onus off of programmers, esp with regard to companies that don't have big budgets. sounds like a really good idea, and with quad core and upwards it really does make a hell of a lot of sense. i mean even if u had one core dedicated to the calculations required for this out of 4 the improvements in single threaded would be immense!! huzzah for amd!!!

17th Apr 2006, 17:01	#17
_Kat_ Minimodder Join Date: Jan 2006 Location: The Netherlands Posts: 42	I'd stick to dual and quad cores... I just don't see the point of a 10 Ghz core which actually excists out of 2 or 3 or 4 cores when you have 4 cores. 4 cores that could be split with hyper treading and then do 8 different things at the same time instead of an extremely fast single core tht does 1 thing very fast. I say 8 different things at the same time is better then 1 thing very fast.

17th Apr 2006, 17:44	#19
Ta10n Minimodder Join Date: Mar 2006 Location: Canada Posts: 46	I think this is a great idea. I've been wondering why they haven't figured out how to use many cores or processors as one. Mad props to AMD on this one. Not only will this make ALL existing programs faster but programers don't have to program for more than one core, saving time and money.