Yokemate of Keyboards
Posts: 12195 from 2003/5/22
From: Germany
> What's your guess as to Varisys' processor of choice?
> I'm thinking something based on the e6500.
If you're talking about the successor to the X1000 here (whose processor would be A-Eon's choice rather than its contractor's), then my opinion has not changed from
what I said in December 2011, which was:
"
A-Eon already hinted at Freescale's QorIQ P4 and P5 chips for future hardware. In my opinion it would be better for them to wait for the availability of the AltiVec-enabled QorIQ AMP (= T series) chips, at least for the X1000 successor, as even the top end P series chips are only a little better performing than the PA6T, if at all, and they lack AltiVec."
Since I made this statement,
1. the QorIQ P series got enhanced from 2.2 GHz (P5010/P5020) to
2.4 GHz (P5021/P5040),
2. benchmark results have shown the PA6T to be underperforming compared to the expectations I had when I said the top end QorIQ P series chips were only a little better performing,
3. it was revealed that the e6500 core will be limited to QorIQ T2 through T5 chips (as
T1 has only e5500).
So it may be that already the P5021/P5040 would be a significant step up from the PA6T, but I still believe it's better to use T4 or even wait for T5 due to them being AltiVec-enabled. The flipside is that real development based on T series chips can not start yet due to lack of sample availability (T4 samples were announced for mid-2012, but I'm not sure they're there already), while with P5 Varisys may have started work as soon as the Nemo v2.1 design was finalized (which was over a year ago).
Leaving AltiVec aside, a DMIPS per core/thread comparison between P5 and T4:
P5: 3.0 DMIPS/MHz * 2400 MHz = 7200 DMIPS
T4: 3.3 DMIPS/MHz * 1800 MHz = 5940 DMIPS
So from that perspective, the P5 has a 20% performance advantage over the T4. Let's see how fast Freescale will get the T5 (announced are 2.5 GHz, i.e. 8250 DMIPS per core and thus 15% higher Dhrystone performance per core than P5).