AMD Reverse Hyperthreading?

[TheTaz]

Found this in The Inquirer...

Also on X86-secret, there are rumors that AMD is preparing a reverse Hyperthreading for the K10 which would allow one thread to run on two or more cores.

Which is a summary of this French site: X86-secret.com (http://www.x86-secret.com/?option=newsd&nid=933)

Since the Bablefish translation is nasty... maybe someone that's good with French can translate it more accurately.

Anyway... if this rumor is true... I assume it means that Applications won't have to be specifically "multi-threaded", in order to take advantage of multiple cores. (Which would be a big boost for any application)

Thoughts?

[jolle]

Sounds pretty neat if its true.
I think NEC is working on a software solution that will split singlethreaded apps over several cpus.

[CaptNKILL]

That sounds very interesting but I can see this causing a crapload of problems... some games already have enough problems with dualcore CPUs, I cant imagine whatd happen if your CPU was trying to split the game's code amongst multiple CPUs :o

[Lfctony]

Royal Rumble!!! :p

[jolle]

Well current problems are prolly cause the CPU is handled as multicore by the OS and part of the gameengines may not be "built" to handle things that might result of that.
Also pretty much all problems (cept the 64fps cap on WOW) is fixed on my rig with XP hotfix and X2 driver, so its not hopeless..
Anyhow, while if the CPU was emulating a single core somehow, that could prolly be transparent to OS and game.. and they cant verywell release a buggy hardware implementation, that would be a disaster hehe..

but you never know, its presumably very complicated stuff since it hasnt been done yet.

[AthlonXP1800]

Very interesting, I think K9 was now canned in favour of K8L, after K8L come out in Q4 2006 and K10 will be next one to replace K8L.

[tieros]

I think what they are talking about is the ability to treat multiple cores as a single multi-core CPU. Imagine taking an 8 blade server and treating it as a single 8 (or 16) core CPU. Basically, it's SLI for CPUs :D

It would use Hypertransport as the glue, so it gives them a low-cost way to scale past anything Intel tries to throw at them.

I hope they target the consumer space with this. I'd love a small PC with dual x2 3800/1GB RAM cards and dual 7900GT cards :D

[jolle]

I think what they are talking about is the ability to treat multiple cores as a single multi-core CPU.
Well, looking at the strange translated text, it does seem as if they are trying to run singlethreaded software over multicore CPUs.. not running multiple CPUs as one Multicore CPU.
Getting the benefit without having to write the application multithreaded, and possibly potentially getting even more out of it as alot of applications wont ever be perfectly balanced to evenly load both cores to the max..

[spoop]

Sounds too good to be true to me...

[tieros]

I didn't see any reference there to threading single threaded apps. It specifically mentioned combining 2 dual core CPUs into a single virtual quad core one.

I tried a couple of different webpage translators, but they all looked pretty much the same. Hopefully a longer discussion of it will show up in English somewhere soon :D

[Bman212121]

Well, looking at the strange translated text, it does seem as if they are trying to run singlethreaded software over multicore CPUs.. not running multiple CPUs as one Multicore CPU.
Getting the benefit without having to write the application multithreaded, and possibly potentially getting even more out of it as alot of applications wont ever be perfectly balanced to evenly load both cores to the max..

It sounds very interesting indeed. Now if we only had a more reliable source, it might actually be true. :)

BTW, YOU STOLE MY RIG! :) Running CPU @2.3GHZ, AGP 6800GT, didn't get the X-FI yet, but I'd be getting the Platinum cause of the optical out.

[JoKeRr]

Google Intel Mitosis

actually here: http://www.intel.com/technology/magazine/research/speculative-threading-1205.htm

[Blakhart]

I see latency issues....

[jolle]

I didn't see any reference there to threading single threaded apps. It specifically mentioned combining 2 dual core CPUs into a single virtual quad core one.

Not threading singlethreaded apps, but have the CPU "look" like 1 core for the OS, and thus running the singlethreaded app across both cores.
Quoting the translation:
it is a question for AMD of emulating a single virtual processor with two (or several) physical processors.

A mother chart comprising two Dual CPU Core would be thus seen by the operating system only like one processor, well on theoretical power four times higher than that of four CPUs.
Well, ok I can se what you mean, combining physical CPUs aswell.
But it still sounds to me, that the point is to have a singlethreaded APP running across all cores/CPUs as they were one, emulating one core with many.
Not just "gluing" in more cores from outside the system, which would only add to multithreaded apps with a ton of threads going on.

BTW, YOU STOLE MY RIG! :) Running CPU @2.3GHZ, AGP 6800GT, didn't get the X-FI yet, but I'd be getting the Platinum cause of the optical out.
Bwahaha.. Couldnt get that CPU any higher either? guess we got unlucky..
Btw Im currently running a 7900GTX, but I dont know for how long, NV sent it for a review I was writing hehe.
Good soundcard btw, I went from years of integrated, CMSS-3D Headphone is great, most of the time.. bugs with oblivion tho..

[tieros]

Not threading singlethreaded apps, but have the CPU "look" like 1 core for the OS, and thus running the singlethreaded app across both cores.
Quoting the translation:


it is a question for AMD of emulating a single virtual processor with two (or several) physical processors.



I took this to mean a single virtual multicore CPU as opposed to a virtual single core CPU. Since AMD is so hot and heavy into virtualization now with Pacifica, it seems like a logical next step. First make one computer look like multiple computers, then make multiple computers look like one.

What you're saying makes sense too, though, especially since it was referred to as inverse HT.

Hopefully more goodies will leak out soon :D

[nemecb]

I can see this being possible at the instruction level, but that wouldn't really involve threading as I understand it. There's already a bunch of concurrency going on with CPU pipelines so I suppose sending instructions to two cores and combining the results makes a certain amount of sense. In any case it seems like this would be very complicated so I wish them luck.

[Karl_uk]

I agree, this will take some serious engineering but I wish them the best of luck. I found this on the subject a while ago, the second post down explains the main problem in implementing it.

http://forums.bit-tech.net/showthread.php?t=111289&page=3&pp=20

[retsam]

im wondering if this is going to need a custom HAl for this to work properly in windows...i cant see this working without some sort of software layer to help this move along in the right direction.