Inside Intel's Core i7 Processor, Nehalem 146
MojoKid writes "Intel's next-generation CPU microarchitecture, which was recently given the official processor family name of
'Core i7,' was one of the big topics of discussion at IDF. Intel claims that Nehalem represents its biggest platform architecture change to date. This might be true, but it is not a from-the-ground-up, completely new architecture either. Intel representatives disclosed that Nehalem 'shares a significant portion of the P6 gene pool,' does not include many new instructions, and has approximately the same length pipeline as Penryn. Nehalem is built upon Penryn, but with significant architectural changes (full webcast) to improve performance and power efficiency. Nehalem also
brings Hyper-Threading back to Intel processors, and while Hyper-Threading has been criticized in the past as being energy inefficient, Intel claims their current iteration of Hyper-Threading on Nehalem is much better in that regard."
Update: 8/23 00:35 by SS: Reader Spatial points out Anandtech's analysis of Nehalem.
Slashdotted (Score:5, Informative)
how much is enough? (Score:5, Informative)
At this point, as long as I can watch HD video without any noticeable slowdowns, I'm good. A GPU or integrated video solution that can do that plus some energy efficient CPU is really all I'm interested now. The software issues with the 4500HD are disappointing, but hopefully it's *just* a software issue this time, and can be fixed soon enough.
Then again, that's just me; I'm not a gamer or video editor.
Re:That old question (Score:3, Informative)
Re:Here we go again (Score:5, Informative)
Re:only the super high desk tops have Quick Path a (Score:3, Informative)
Re:only the super high desk tops have Quick Path a (Score:1, Informative)
Re:Here we go again (Score:3, Informative)
8 threads per core in Niagara 2; you get up to 64 threads, as the chip is available with 4, 6 or 8 cores.
Re:yeah, yeah, yeah.. they said this the last time (Score:5, Informative)
The problem with hyperthreading is that it fails to deal with the fundamental problem of memory bandwidth and latency
The entire point of SMT (of which HT is am implementation) is that it helps hide memory latency. If one thread stalls waiting for memory then the other gets to use the CPU. Without SMT, then a cache miss stalls the entire core. With SMT, it stalls one context but the other can keep executing until it gets a cache miss, which hopefully doesn't happen until the other one has resumed.
Re:Power effiiency is the new "it" (Score:1, Informative)
I have been using Nvidia graphics hardware for the pass 2+ years (before that had an ATI 9600 XT - another good value for money card at that time, and more Nvidia cards from the pre-geforce days till then)
Recently I got myself an ATI 4850 card primarily cos of the open sourc'ing of the drivers.
I also got a 4870 card for another friend of mine (Gamer + office related work).
I also run Vista on my system whereas my friend dual boots Vista / XP.
We both have had blue screens due to the driver at least once so far (running 8.8 Catalyst - the latest) and under Vista the system had to recover from grapichs driver issues.
It is nice to have a good piece of hardware which is very good value for money, but current windows drivers have not been very stable so far (both XP / Vista).
As I don't do much graphics work in Linux, I can't comment on that.
Not on the desktop it isn't (Score:5, Informative)
> Desktop users think electricity costs.
Bullshit. The difference between a 130W Nehalem and a 65W Core2 is 65W, which is 11 cents per day (at 7c/kW) or $39/year if you run the computer 24/7. Most people turn the computer off when it's not in use, and 8 hours per day is more likely, or 3 cents per day and maybe $10/year. I'd say the cost is entirely negligible, especially when you compare it to your $80/month Comcast bill.
Re:Here we go again (Score:3, Informative)
Most applications have inherently parallel workloads that are implemented in sequential code because context switching on x86 is painfully expensive.
Context switching on x86 is dead cheap. It's probably the cheapest of all general purpose architectures available right now. We're talking a few hundred cycles cheap. Only the P4 is a bit behind, and Nehalem makes things faster, to the point where Intel almost catches up with AMD.
Windows manages to make process switches a lot more expensive than necessary, but thread switching isn't bad. With Linux it hardly matters whether you switch processes or threads, they're both fast.
Re:Here we go again (Score:3, Informative)
Unfortunately those are very, very, very, very, very niche workloads. Your workloads have to be insanely parallel and each thread very independent of others so that you have little that is blocking. In short, Niagra is just marketing.
Re:Will OS X's Snow Leopard use HT more? (Score:3, Informative)