IBM's Eight-Core, 4-GHz Power7 Chip

pacopico writes "The first details on IBM's upcoming Power7 chip have emerged. The Register is reporting that IBM will ship an eight-core chip running at 4.0 GHz. The chip will support four threads per core and fit into some huge systems. For example, University of Illinois is going to house a 300,000-core machine that can hit 10 petaflops. It'll have 620 TB of memory and support 5 PB/s of memory bandwidth. Optical interconnects anyone?"

Comments

Great

[afidel]

So you can get 16 cores in a low end box but it still won't have enough I/O slots so you will have to buy a shelf at $obscene_amount, seriously why does IBM put such few I/O slots in the lower end P series boxes?

4 Threads per core?

[jdb2]

It should be noted that previous POWER architectures had 2 threads per core. They also had SMT ( Simultaneous Multi-Threading ) support, which gave them an "effective" 4 threads per core. I wonder. Are the all the threads on the POWER7 "true" threads ( ie. 4 execution units -- 1 per thread ) or is it a 2 thread setup with SMT? On the other hand, if the POWER7 really does have 4 "true" threads, then with SMT you'd get an "effective" *8* threads per core.

jdb2

Re:I have a serious question:

[jcarkeys]

You sir, are correct. Most things aren't set to run in parallel and thus don't get the gains. Gains come from optimized code (obviously), but also doing multiple tasks. Leave Photoshop to render an HDR image and play a game, if you want. Though to be fair, it's not "just 1/4th" performance, the other cores are able to handle some of the other CPU tasks, such as running hardware controllers.

And the reason that it kind've oscillates between cores is because "Set Affinity" tells the process that it's allowed to use that core, not that it has to or even should. If you want something to use both cores, open up two processes, set the first to core 1 and the second to core 2. Most of the time that's unusable like that, but I recently transcoded my entire music library and set one process to do songs from A-M, and the other from N-Z. It really helped

Memory Bandwidth

[Brad1138]

It'll have 620 TB of memory and support 5 PB/s

Is that kind of memory bandwidth possible? You could access the entire 620TB in ~120 milliseconds. I guess nothing is ever to fast, it just seems unrealistically fast.