By: juanrga (nospam.delete@this.juanrga.com), February 4, 2015 4:06 pm
Room: Moderated Discussions
Wilco (Wilco.Dijkstra.delete@this.ntlworld.com) on February 4, 2015 4:01 pm wrote:
> juanrga (nospam.delete@this.juanrga.com) on February 4, 2015 5:23 am wrote:
> > Wilco (Wilco.Dijkstra.delete@this.ntlworld.com) on February 4, 2015 1:58 am wrote:
> > > juanrga (nospam.delete@this.juanrga.com) on February 3, 2015 5:15 pm wrote:
> > > > Hugo Décharnes (hdecharn.delete@this.outlook.fr) on February 3, 2015 2:20 pm wrote:
> > > > > Cortex-A57 delivers better performances than Cortex-A15, though their micro-architectures
> > > > > are–nearly–identical. We'll see if ARM Ltd. reiterates with Cortex-A72.
> > > >
> > > > More than 80% performance gains over A57.
> > >
> > > ... but it was clearly stated that this is at the same mobile power
> > > budget. So the gains are from improved power efficiency.
> > >
> > > > ~50% IPC gain over A57, rest from ~30% higher clocks.
> > >
> > > I didn't read anything that indicated such a huge IPC gain. Peak performance should be much better of
> > > course, but much of that will be due to higher frequencies enabled by the improved power efficiency.
> > >
> > > Wilco
> > >
> > >
> >
> > I did read the preliminary analysis here
> >
> > http://techreport.com/news/27767/arm-unveils-cortex-a72-cpu-mali-t880-graphics-and-more
>
> That analysis is wrong, ignoring the fact that the comparison is at identical power, not at max
> frequency. The large gain in power efficiency allows the A72 to run at a higher frequency than
> A57 or A15, even on the same process. That means the 80% benefit is split between frequency gains
> enabled by lower power on the same process, frequency gains due to FinFet and IPC gains. Let's
> say the average IPC gain is 20% (probably not far off given the range Peter mentioned), so that
> means the frequency gain is 50% (1.5 * 1.2 = 1.8, something else Techreport got wrong).
>
> Wilco
First, thanks by the explanation.
I did just read his post and the 10--50% IPC gains, bad luck he didn't mention averages, we will have to wait to check by ourselves.
> juanrga (nospam.delete@this.juanrga.com) on February 4, 2015 5:23 am wrote:
> > Wilco (Wilco.Dijkstra.delete@this.ntlworld.com) on February 4, 2015 1:58 am wrote:
> > > juanrga (nospam.delete@this.juanrga.com) on February 3, 2015 5:15 pm wrote:
> > > > Hugo Décharnes (hdecharn.delete@this.outlook.fr) on February 3, 2015 2:20 pm wrote:
> > > > > Cortex-A57 delivers better performances than Cortex-A15, though their micro-architectures
> > > > > are–nearly–identical. We'll see if ARM Ltd. reiterates with Cortex-A72.
> > > >
> > > > More than 80% performance gains over A57.
> > >
> > > ... but it was clearly stated that this is at the same mobile power
> > > budget. So the gains are from improved power efficiency.
> > >
> > > > ~50% IPC gain over A57, rest from ~30% higher clocks.
> > >
> > > I didn't read anything that indicated such a huge IPC gain. Peak performance should be much better of
> > > course, but much of that will be due to higher frequencies enabled by the improved power efficiency.
> > >
> > > Wilco
> > >
> > >
> >
> > I did read the preliminary analysis here
> >
> > http://techreport.com/news/27767/arm-unveils-cortex-a72-cpu-mali-t880-graphics-and-more
>
> That analysis is wrong, ignoring the fact that the comparison is at identical power, not at max
> frequency. The large gain in power efficiency allows the A72 to run at a higher frequency than
> A57 or A15, even on the same process. That means the 80% benefit is split between frequency gains
> enabled by lower power on the same process, frequency gains due to FinFet and IPC gains. Let's
> say the average IPC gain is 20% (probably not far off given the range Peter mentioned), so that
> means the frequency gain is 50% (1.5 * 1.2 = 1.8, something else Techreport got wrong).
>
> Wilco
First, thanks by the explanation.
I did just read his post and the 10--50% IPC gains, bad luck he didn't mention averages, we will have to wait to check by ourselves.
Topic | Posted By | Date |
---|---|---|
ARM announces A72 | Maynard Handley | 2015/02/03 11:36 AM |
ARM announces A72 | anon | 2015/02/03 12:53 PM |
ARM announces A72 | Hugo Décharnes | 2015/02/03 01:20 PM |
ARM announces A72 | juanrga | 2015/02/03 04:15 PM |
ARM announces A72 | Wilco | 2015/02/04 12:58 AM |
ARM announces A72 | Eric Bron | 2015/02/04 01:48 AM |
ARM announces A72 | none | 2015/02/04 02:24 AM |
ARM announces A72 | Eric Bron | 2015/02/04 02:42 AM |
ARM announces A72 | Exophase | 2015/02/04 07:01 AM |
ARM announces A72 | Anon | 2015/02/04 07:35 AM |
ARM announces A72 | Exophase | 2015/02/04 07:58 AM |
ARM announces A72 | Groo | 2015/02/04 09:24 AM |
ARM Marketing, BS up to my ears | David Kanter | 2015/02/04 10:51 AM |
ARM Marketing, BS up to my ears | Maynard Handley | 2015/02/04 01:59 PM |
ARM Marketing, BS up to my ears | David Kanter | 2015/02/04 02:21 PM |
ARM Marketing, BS up to my ears | Groo | 2015/02/04 02:30 PM |
ARM announces A72 | juanrga | 2015/02/04 04:23 AM |
ARM announces A72 | Wilco | 2015/02/04 03:01 PM |
ARM announces A72 | juanrga | 2015/02/04 04:06 PM |
ARM announces A72 | Anon | 2015/02/04 01:28 AM |
ARM announces A72 | juanrga | 2015/02/04 04:31 AM |
ARM announces A72 | Aaron Spink | 2015/02/04 06:49 AM |
ARM announces A72 | Ronald Maas | 2015/02/03 07:23 PM |
ARM announces A72 | Seni | 2015/02/04 12:19 AM |
ARM announces A72 | Maynard Handley | 2015/02/04 10:42 AM |
ARM announces A72 | Seni | 2015/02/04 12:33 PM |
ARM announces A72 | dmcq | 2015/02/04 12:57 PM |
ARM announces A72 | Ronald Maas | 2015/02/04 06:42 PM |
ARM announces A72 | anon | 2015/02/04 05:19 AM |
ARM announces A72 | Exophase | 2015/02/04 07:31 AM |
ARM announces A72 | David Kanter | 2015/02/04 10:25 AM |
ARM announces A72 | Exophase | 2015/02/04 01:33 PM |
ARM announces A72 | anon | 2015/02/04 10:27 PM |
ARM announces A72 (fixed format) | anon | 2015/02/04 10:29 PM |
ARM announces A72 | Exophase | 2015/02/04 11:11 PM |
ARM announces A72 | anon | 2015/02/05 12:02 AM |
ARM announces A72 | anon | 2015/02/04 05:57 PM |
ARM announces A72 | Wilco | 2015/02/03 01:39 PM |
ARM announces A72 | Maynard Handley | 2015/02/03 02:13 PM |
ARM announces A72 | anon | 2015/02/03 02:29 PM |
ARM announces A72 | Wilco | 2015/02/03 02:44 PM |
ARM announces A72 | David Kanter | 2015/02/04 09:56 AM |
ARM announces A72 | Peter Greenhalgh | 2015/02/04 10:56 AM |
ARM announces A72 | Aaron Spink | 2015/02/04 11:59 AM |
ARM announces A72 | Alberto | 2015/02/07 10:22 AM |
ARM announces A72 | Exophase | 2015/02/07 10:47 AM |
ARM announces A72 | Alberto | 2015/02/07 12:44 PM |
ARM announces A72 | Exophase | 2015/02/07 02:35 PM |
ARM announces A72 | Alberto | 2015/02/08 01:09 AM |
ARM announces A72 | Exophase | 2015/02/08 11:05 AM |
ARM announces A72 | David Kanter | 2015/02/08 12:39 AM |
ARM announces A72 | dmcq | 2015/02/08 04:14 AM |
ARM announces A72 | Michael S | 2015/02/08 04:38 AM |
ARM announces A72 | Gabriele Svelto | 2015/02/10 05:11 AM |
ARM announces A72 | Jouni Osmala | 2015/02/10 11:24 AM |
slit vs unified | Michael S | 2015/02/10 01:57 PM |
slit vs unified | dmcq | 2015/02/11 05:44 AM |
ARM announces A72 | Doug S | 2015/02/08 09:00 AM |
ARM announces A72 | Exophase | 2015/02/08 10:57 AM |
ARM announces A72 | dmcq | 2015/02/04 01:10 PM |
ARM announces A72 | David Kanter | 2015/02/04 02:28 PM |
ARM announces A72 | Wilco | 2015/02/04 01:59 PM |
ARM announces A72 | Aaron Spink | 2015/02/04 09:31 PM |
Intel 32nm vs 14 nm | Michael S | 2015/02/05 01:03 AM |
Intel 32nm vs 14 nm | Wilco | 2015/02/05 02:27 AM |
Intel 32nm vs 14 nm | David Kanter | 2015/02/05 09:05 AM |
Intel 32nm vs 14 nm | carop | 2015/02/05 11:12 AM |
Normalize to drawn or effective width? | David Kanter | 2015/02/05 11:45 AM |
Normalize to drawn or effective width? | carop | 2015/02/05 02:40 PM |
Normalize to drawn or effective width? | David Kanter | 2015/02/06 12:44 PM |