Linked by Thom Holwerda on Wed 31st Oct 2012 00:46 UTC
Windows "Taiwanese computer maker Acer is putting off the launch of tablets using Microsoft's new Windows RT operating system to give itself time to see how Microsoft's own Surface tablet fares. The world's No. 4 PC vendor by shipments initially planned to roll out Windows RT tablets based on ARM chips early next year. However, the launch of Microsoft's tablet last week and the mixed reviews it has drawn has prompted Acer to wait and see until at least the second quarter of 2013." Whatever the reason, this doesn't send a very promising message about Windows RT. Or, not entirely unlikely, Acer and other OEMs just can't measure up to Surface RT.
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Alfman
Member since:
2011-01-28

bassbeast,

"The problem with ARM is it just doesn't scale well and it has lousy IPC. Companies like Nvidia have spent crazy money on ARM R&D and still can't overcome the weak IPC and the scalability problem, which is why Tegra is up to 5 cores now."

I don't know, I think most engineers would claim that being able to support many cores IS an example of good scalability. There's been a long debate over having very deep complex logic gates required to run serial logic in parallel pipelines versus having more cores on the same die space. Also, ARM has some advantages on the opcode level which can significantly reduce branching for free.

Not to dis intel though, I'm impressed with how they can essentially recompiling code on the fly to get more parallelism out of sequential instructions, it's truly an incredible feat. But this complexity has a cost, it requires more gates and power. This may be somewhat mitigated by the fact that intel has die fabrication advantages. But these pipeline gates could have gone to parallel cores instead, which theoretically should perform even better with software that can take advantage of it.

Serial programming is not scalable and deep pipelines cannot increase single thread performance any longer. The more prevalent concurrent programming becomes, the better ARM processors will perform per gate compared to x86 counterparts. More so if they use the same manufacturing technology (since ARM lags behind).

Here are some benchmarks comparing various mobile x86 and ARM processors, unfortunately they haven't included any x86 server processors for reference. Never the less, even with a faster clock, the atom does not win on all performance tests, and it consumes much more power!

http://www.brightsideofnews.com/news/2011/5/19/the-coming-war-arm-v...

http://www.brightsideofnews.com/news/2011/5/19/the-coming-war-arm-v...

Edited 2012-11-01 14:47 UTC

Reply Parent Score: 3

bassbeast Member since:
2007-11-11

Uhhh..your own link shows the Atom 2 generations behind curbstomping the ARM chip, and again we are talking about a downclocked single core from TWO generations ago, which is like a decade ago in mobile terms. this merely illustrates what i was talking about, that Intel has a high enough IPC that even on underclocked chips they are getting crazy numbers, now imagine what they are gonna get with Haswell, which rumors place at having damned near first gen Core performance with a sub 5w envelope?

And the fact that you can't keep adding cores again plays into Intel's strength, because as your own charts show the IPC of even the two generations behind Atom single core gives great performance. Nvidia is already up to 5 cores trying to get the IPC that people want from modern mobiles and you are right, you can't keep piling on cores, nor can you keep covering up for weakness in the ARM design with "helper chips" like the Broadcom decoders.

I just think the future doesn't look bright for ARM in the smartphone and especially the tablet, where people want high quality graphics, and gaming, and HD videos, and everything they are used to in a laptop, because ARM's IPC just isn't high enough and so far nobody has been able to get ARM cores to run with a high enough IPC without blowing the budget.

Reply Parent Score: 1

Alfman Member since:
2011-01-28

bassbeast,

"Uhhh..your own link shows the Atom 2 generations behind curbstomping the ARM chip, and again we are talking about a downclocked single core from TWO generations ago, which is like a decade ago in mobile terms."

This was a 2011 benchmark that showed some relationships for both power and performance, if you have a better one from 2012 I'd be happy to use that instead. Anyways, in your preceding post, you explicitly said Atom should underclock the core to get a lower energy footprint, which I agree with, but now your complaining that this benchmark actually did that.

For the record, the VIA ARM Nano was 1.8GHZ underclocked to 44%, whereas the Atom was 1.67GHZ underclocked to 60%. The intention was to test at the same clock speed, but the Atom wouldn't run below 1GHZs, I quote: "Unfortunately, it was impossible to downclock the 1.67GHz Atom N450 below 1GHz, but, as you will see, the results we obtained are still very interesting."

I'd wager a guess that for native speeds at that time, the Nano's CPU-bound results would get multiplied by 2.25 and the Atom's by 1.67, such that the Nano core would increase 35% relative to the Atom core. I don't have a predisposition for ARM, that's just what the data tells me.


"And the fact that you can't keep adding cores again plays into Intel's strength, because as your own charts show the IPC of even the two generations behind Atom single core gives great performance."

These tests were for single cores, so no advantage was given for having more cores.


"I just think the future doesn't look bright for ARM in the smartphone and especially the tablet, where people want high quality graphics, and gaming, and HD videos, and everything they are used to in a laptop, because ARM's IPC just isn't high enough and so far nobody has been able to get ARM cores to run with a high enough IPC without blowing the budget."


Why do I feel like that's a sales pitch for intel more than an objective analysis? Intel does a great job at high end performance where energy isn't factored in, but every report I've come across showed ARM leading on efficiency, which is why they're so popular in mobiles. While it's conceivable for Atom to close the gap, I haven't seen any data that shows that, have you (*)?

* Edit: Obviously, if so, please post!

Edited 2012-11-02 00:17 UTC

Reply Parent Score: 2