1. This forum section is a read-only archive which contains old newsgroup posts. If you wish to post a query, please do so in one of our main forum sections (here). This way you will get a faster, better response from the members on Motherboard Point.

Xbox360 IBM PowerPC CPU: 3.2 GHz. 3 processing cores. 6 threads. 165m transistors

Discussion in 'Intel' started by Guest, May 13, 2005.

  1. Guest

    Guest Guest

    when reports came out in early 2004 about the Xbox2 CPU having three PowerPC
    cores, each capable of two threads (6 threads total) running at over 3
    GHz, people here said that just could not or would not happen. well, it is
    apparently happening.

    the only weakness I can see (as a non-tech person) is the small 1 MB of L2
    cache, shared between all 3 cores.

    the whole CPU is 165 million transistors. compared to Xbox's Intel CPU
    which is 20 to 25 million, and PS2's CPU which is ~13 million.

    Avoiding Bottlenecks

    "As we've seen on the PC side, it's very important to make sure the CPU and
    GPU are well matched to make sure the system functions at maximum
    efficiency. If you pair an underpowered CPU with a powerful GPU, the CPU
    will bottleneck system performance, and all that extra GPU power will go to
    waste. Microsoft decided early on to go with a multicore CPU design after
    deciding that a superfast single-core CPU wouldn't be a viable option, since
    the processor would be difficult to shrink down when the time would come to
    reduce costs. This shift from single-core to multicore processing is
    happening right now in the desktop market, as Intel and AMD are just
    starting to ship dual-core processors this year.

    The Xbox 360 will have a custom-designed IBM processor that has three
    processing cores, each capable of handling two threads, or two separate
    applications. Six total threads provides a lot of processing power, but it
    adds to the software complexity, because you now have to manage resources
    between all the processes. Microsoft has a lot of experience with
    multithreaded applications, and the company is confident that developing on
    the processor won't be a problem. It might take developers a while to figure
    out the most efficient way to use all the threads, but the large number of
    threads will give programmers a lot of flexibility. The 165-million
    transistor chip will run at 3.2GHz, and it'll have a vacuum-sealed,
    water-cooled heat sink to handle heat dissipation."

    Guest, May 13, 2005
    1. Advertisements

  2. Guest

    Guest Guest


    I forgot to mention, the CPU is rated at 115.2 GFLOPs.

    sources for the CPU floating point performance figure

    that is alot of flops for being a fairly conventional CPU and not something
    exotic like CELL.

    (i'm totally ignoring the PR-speak "1 TFLOP" total system performance which
    counts mostly as GPU and thus,
    is not general purpose FLOPs)
    Guest, May 13, 2005
    1. Advertisements

  3. Guest

    Yousuf Khan Guest

    IBM does like to pile on the cores doesn't it? Xbox, Cell, etc.

    Even using 512MB of GDDR3 as its main memory. It seems to have
    everything on paper.

    Yousuf Khan
    Yousuf Khan, May 14, 2005
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.