I should add that using the highly parallelizable transcoding software Handbrake on my i7 Lynnfield rig, enabling HT only results in a 7% increase in performance, and that just barely makes up for the 5% die size increase required for supporting HT. In other words, HT largely still remains the gimmick it was when introduced in the Netburst architecture. It makes people and the OS think there are twice the resources, when really there aren't.
Moreover, the Atom's are in-order architectures, and it's my understanding HT is utilized mainly to make up for their long pipelines and in-order architectures where a branch misprediction will incur significant overhead (entire 16 stage pipeline has to be flushed and filled again with instructions before the actual execution units gets something to work with). On Aug 4, 12:52 pm, Casper Bang <[email protected]> wrote: > HT only dublicates part of the CPU though, mainly those parts dealing > with state - there is still only two ALU's doing real work in the > n550, so the notion of a virtual CPU (one without execution units) > having an independent clock speed, makes little sence (to me anyway). > > Where HT shines is with long pipelines and unpredictable work (cache > miss and prefetch errors). Indeed most people sees only an improvement > of 10 -30%. Are you seeing more than that? And under which conditions? > > On Aug 2, 4:16 pm, Dick Wall <[email protected]> wrote: > > > > > > > > > yep - sorry folks - I thought I should have clarified this at the time. It > > is dual core, with 2 threads per core. Each thread can have it's own > > independent clock speed, so one or all can fire up to full speed or draw > > back to power saving independently. The upshot is that 4 things can be > > happening in the same clock cycle, and the point was to demonstrate that > > parallel processing is here on even the smallest machines. My netbook is a > > EEEPC 1015PEM, it gets about 6-8 hours from a charge, and can compile our > > non-trivial scala codebase just fine, along with producing many of the Java > > Posse episodes using Audacity. It fits in my bicycle pack as well. I love it > > :-) -- You received this message because you are subscribed to the Google Groups "The Java Posse" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/javaposse?hl=en.
