Remember that each of these processing cores will have to share their memory bandwidth and possibly level 2 cache as well. As it is Intel's EM64T Xeon processors really feel the bandwidth bottleneck in their memory interface and can easily saturate it.
What you're saying is, for applications with poor cache performance, multi-core processors will be no better than single-core. Personally, I can live with that. Most of the processor developments of the last 10 years have favored applications with good cache performance.
What worries me is what happens when the OS schedules a process with good cache performance on one core, and a process with poor cache performance on the other core. Unless the cache does something special to prevent it, the "bad" process will completely deplete the cache, causing the "good" process to slow way down.
I recently worked on a real-time program for the Pentium IV, and we found that our worst-case performance was actually 4-5 times worse when hyperthreading was enabled, because our process would occasionally have to share its cache with something that was heavily memory-bound.
DVD and CD would actually be better for this sub
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Giant Sub-Woofer
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· Score: 1
Note that you won't get the full range of the subwoofer with a DVD or CD. Both have a bottom limit of 20 Hz, while the sub in question can allegedly output down to 10 Hz flat (and well below that with fall off).
Actually, CD's are perfectly capable of carrying frequencies down to 0 Hz, as are Dolby Digital encoded DVD's. I don't know first hand about MP3, DTS, or MLP, but there's no reason they wouldn't go down to 0 Hz either. The reason is bandwidth: since the range of frequencies between 0 and 20 Hz is so tiny, they take up a very small number of bits in the bitstream. It would take extra work to exclude those frequencies from the format, for no tangible gain.
LP's, on the other hand, pick up a lot of ultra-low-frequency noise that's not on the record (trucks going by, warping of the record itself, etc.) Any phonograph preamp worth its salt will filter out anything below about 20 Hz to prevent those noises from getting to the speaker and distorting the rest of the audio.
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What you're saying is, for applications with poor cache performance, multi-core processors will be no better than single-core. Personally, I can live with that. Most of the processor developments of the last 10 years have favored applications with good cache performance.
What worries me is what happens when the OS schedules a process with good cache performance on one core, and a process with poor cache performance on the other core. Unless the cache does something special to prevent it, the "bad" process will completely deplete the cache, causing the "good" process to slow way down.
I recently worked on a real-time program for the Pentium IV, and we found that our worst-case performance was actually 4-5 times worse when hyperthreading was enabled, because our process would occasionally have to share its cache with something that was heavily memory-bound.
Note that you won't get the full range of the subwoofer with a DVD or CD. Both have a bottom limit of 20 Hz, while the sub in question can allegedly output down to 10 Hz flat (and well below that with fall off).
Actually, CD's are perfectly capable of carrying frequencies down to 0 Hz, as are Dolby Digital encoded DVD's. I don't know first hand about MP3, DTS, or MLP, but there's no reason they wouldn't go down to 0 Hz either. The reason is bandwidth: since the range of frequencies between 0 and 20 Hz is so tiny, they take up a very small number of bits in the bitstream. It would take extra work to exclude those frequencies from the format, for no tangible gain.
LP's, on the other hand, pick up a lot of ultra-low-frequency noise that's not on the record (trucks going by, warping of the record itself, etc.) Any phonograph preamp worth its salt will filter out anything below about 20 Hz to prevent those noises from getting to the speaker and distorting the rest of the audio.