New CELL Article Online

Article: CELL Microprocessor III
By: Anonymous ((Not Given)), August 3, 2005 4:11 pm
Room: Moderated Discussions
David Wang ( on 8/2/05 wrote:
>mas () on 8/2/05 wrote:
>> So with 7 SPEs we can say for every cycle the SPEs provide
>>2 DP FMADD and the PPE 1 DP FMADD giving 6 DP flops/cycle. 3.2 Ghz gives 19.2 peak
>>DP GFlops which means for reference that I2/P5 could match this peak at 4.8 Ghz
>>although how much a Cell could sustain in practice is not certain.
>It'll be harder to maintain peak DP FP, especially since you have to use separate
>tool chains for the SPE and the PPE. So you have to do a clean-sheet re-think about
>how to utilize the asymmetric threading model and keep the functional units busy.
>I think that you'll probably have to make your choice to run with "legacy" PPC ISA
>and get the FP performance there, or go with the SPE only.

Fair enough, that makes Xenon only look better then.

>OTOH, if you looked at the photo micrographs of the SPE and the PPE closely, you'll
>see that the PPE itself isn't that much larger than the SPE, and if there's a market
>for this sort of thing, IBM could spin a DD3 where the 7 cycle penalty for DP FMADD
>goes away. Such a chip could crank out enormous amounts of (peak) DP FP, but the
>flop to BW ratio would be heavily skewed to the flop side of things, even if IBM goes with 8 Gb/s/pin-pair XDR2.
>> Coincidentally
>>by having 3 PPEs the Xenon in Xbox 360 could match that DP figure with its SP rate
>>being 76.8 Gflops vs Cell's 204.8 so it doesn't look so outclassed as one would
>>think given Cell's hype.

If the PPE really is 12 SP Flops/cycle, then that comparison above becomes 115.2 to 218 Gflops.

>> I have also heard development Cell kits are only at 2.4
>>Ghz. Anyway they both sound like great distributed computing clients I hope Sony
>>and Microsoft allow them to be used in that ancillary fashion.
>If they're going to heavily subsidize the consoles, they may not like the idea
>of people buying them for compute farms.

MS look like they are with a $299 price but Sony are not in any sort of mood to do so with $450-499 being bandied about. At that differential the Xenon looks the better deal and it also would probably make the better general-purpose computer too with 3 conventional PPC-type cores.
< Previous Post in ThreadNext Post in Thread >
TopicPosted ByDate
New CELL Article OnlineDavid Kanter2005/08/02 11:32 AM
  New CELL Article Onlinemas2005/08/02 12:46 PM
    New CELL Article Onlinemas2005/08/02 12:53 PM
    New CELL Article OnlineDavid Wang2005/08/02 01:46 PM
      New CELL Article Onlinefastpathguru2005/08/02 04:05 PM
        New CELL Article OnlineDavid Wang2005/08/02 06:27 PM
          New CELL Article OnlinePanajev2001a2005/08/03 03:26 AM
            New CELL Article OnlineDavid Wang2005/08/03 11:28 AM
              New CELL Article OnlineDeadmeat2005/08/04 01:05 PM
                New CELL Article OnlineDavid Wang2005/08/04 05:47 PM
                  New CELL Article OnlineDeadmeat2005/08/04 07:04 PM
                    New CELL Article Onlinejohn evans2005/08/04 08:30 PM
                      New CELL Article OnlineDeadmeat2005/08/05 12:10 PM
                        New CELL Article OnlineLinus Torvalds2005/08/05 06:21 PM
                          New CELL Article OnlineDeadmeat2005/08/05 07:33 PM
                            New CELL Article Onlinefastpathguru2005/08/05 10:36 PM
                              New CELL Article Onlinejohn evans2005/08/05 10:51 PM
                              New CELL Article OnlineDeadmeat2005/08/06 04:09 AM
                                New CELL Article Onlinefastpathguru2005/08/06 06:29 AM
                                  New CELL Article OnlineDeadmeat2005/08/07 04:06 PM
                    New CELL Article OnlineDavid Wang2005/08/04 09:03 PM
                      New CELL Article OnlineDeadmeat2005/08/05 12:21 PM
                        New CELL Article OnlineDavid Wang2005/08/05 11:51 PM
              New CELL Article OnlineDavid Wang2005/08/06 12:00 AM
                New CELL Article OnlineDeadmeat2005/08/07 03:39 PM
                  New CELL Article OnlineDavid Wang2005/08/08 01:57 PM
                    New CELL Article OnlineDeadmeat2005/08/08 02:55 PM
                      New CELL Article OnlineDavid Wang2005/08/08 03:37 PM
                        New CELL Article OnlineDeadmeat2005/08/08 05:05 PM
                          New CELL Article OnlineDavid Wang2005/08/08 05:47 PM
                            New CELL Article OnlineDeadmeat2005/08/08 06:25 PM
                              Implausible at best, irrational most likely...David Kanter2005/08/08 06:51 PM
                                Implausible at best, irrational most likely...Deadmeat2005/08/09 10:26 AM
                              New CELL Article OnlineDavid Wang2005/08/08 07:46 PM
                                New CELL Article OnlineDeadmeat2005/08/09 10:36 AM
                                  New CELL Article OnlineDavid Wang2005/08/09 11:12 AM
                                    New CELL Article OnlineDeadmeat2005/08/09 01:26 PM
                                      New CELL Article OnlineDavid Wang2005/08/09 02:36 PM
                                New CELL Article OnlineAaron Spink2005/08/09 02:57 PM
                                  New CELL Article OnlineDavid Wang2005/08/10 10:06 AM
                    New CELL Article OnlineSerge Monkewitz2005/08/09 01:18 PM
                      New CELL Article OnlineDeadmeat2005/08/09 01:30 PM
                        New CELL Article OnlineVitaly Vidmirov2005/08/11 01:36 AM
      New CELL Article OnlineAnonymous2005/08/03 04:11 PM
        New CELL Article Onlinefastpathguru2005/08/03 05:19 PM
          New CELL Article Onlinemas2005/08/03 07:59 PM
            New CELL Article OnlineJosé Javier Zarate2005/08/04 05:20 AM
              New CELL Article Onlinemas2005/08/04 05:27 AM
          New CELL Article Onlinemas2005/08/05 06:50 AM
  New CELL Article OnlinePiedPiper2005/08/02 09:02 PM
Reply to this Topic
Body: No Text
How do you spell avocado?