Atom floating point performance surprise

That's actually not that surprising. No, actually it is. The Athlon X2's are a pretty decent bunch. I was expecting the Atom 330's performance to be even lower (maybe 800MHz?). After all, the Atom's poised to be little better than processors released 8~10 years ago.


The Core 2 and Core i5/i7, perhaps. Definitely not the Atom. Heck, I seem to recall benchmarks showing that the single-core Celeron 430 1.8GHz is faster or on par with the dual-core Atom 330 1.6GHz.

look at netbooks if you are wondering about processors. ANY processor that a netbook can come with is faster than a netbook with an atom processor.

What's the power consumption on that Athlon X2 at 1.1ghz? I bet it's not 17W. You're comparing apples to oranges until you can get an Athlon X2 down to that wattage. The Atom is a scaled down(thusly slower) derivative of laptop processors from 5+ years ago called the Dothan. Do me a comparison on performance per watt and that will have relevance to comparing an Atom to anything else.

Yeh, put it into perspective. The whole point of the Atom is to make a very low power (by this I mean wattage) CPU that's designed for netbooks, tablet PC's etc where battery life is very important. Don't expect blinding peformance. They will run the O/S and apps like IE and Office ok, will play DVD's at SD res, but nothing more without struggling.

Manufacturers are trying to pair them with more powerful GPU's (e.g. ION), to offload as much as possible from the CPU, so you should be able to get 720P or more out of this setup, but it's still hit and miss.

Wait for the next generation of Atom N450 (Pine Trail?). This will use even less power (reckoning 2-3W), but will integrate memory and GPU onto a single die. Should be clocked faster than the current N270 as well.

Yup, Atom (designed by the former PowerPC team in Motorola) is at the heart of the Low Power Intel Architecture (LPIA) project to enter non-PC markets such as CE, embedded, MID.

(Silverthorne is the former codename of Atom.)

It's AMD's Bobcat hat should be compared with (but it's still under development, expected only in 2011!).

- Bobcat (processor) (Wikepedia)

Really? I've been working on the Atom for over 4 years, and I didn't realize that we were the former PowerPC team. I know some of my coworkers used to work at Motorola/Freescale, but many others come from elsewhere or began working for Intel straight out of college.

It is important to remember that the Atom line is also LCIA (Low Cost Intel Architecture). The area of silicon for one Atom CPU is much smaller than its bigger brothers, even when you exclude the L2 cache. It is all about compromises. Sure, you can have faster floating point performance if you change the algorithm and greatly increase the silicon area of the floating point unit, but that will burn more power and use more area. With fewer die per wafer, the cost of each unit will be higher.

The Atom is not going to be a performance competitor to the bigger CPUs, but that's not what it is aiming for. It is aimed at good enough computing at a low cost with low power consumption.

My whole knowledge on this matter is based on Hiroshige Goto's article: IntelのLPIA CPU第2弾「Lincroft」が公開 (October 27, 2008). According to this article (not to me), "central" (not all of course) members of the LPIA development team had worked for Motorola. For example:

- Rajesh Patel (Lead Lincroft Architect; from Motorola)
- Mark McDermott and fifteen CPU architects (from Somerset Design Center, owned by Motorola in '99)
- Gianfranco Gerosa, Mike D'Adde (Silverthorne architects; from Motorola)
- Belli(Belliappa) Kuttanna (Sr. Principal Engineer, Ultra Mobility Group; from Motorola)

But don't ask me details.

Yup, LCIA is another important aspect. LP & LC x86 is also common to Bobcat. (LC aspect is completely negated when it comes to ION HTPC, however.)

Too bad that I can't read whatever language that article is in. But I do recognize some of the names, and work directly with them at times. I see "Tejas" in there, and that was the code name of the project that many of the Atom guys were working on previously.

We have some exciting stuff in the pipeline, but I'm not sure how much of that will be the best choice for performance hungry HTPC users. The Core 2 and Core i* processors will always have more performance than Atom.

You're absolutely right, that was the total platform power consumption, the CPU itself is only rated at 8W. Get an athlong X2 down to that then we can talk. Apples to Oranges. I'm glad your solution works well for you, but don't berrate Atom because you're not using it how it's been designed to be used.

My FreeNAS media server will underclock my old 1.8Ghz Athlon XP down to 300Mhz while idle, and it will still use 11w for the CPU at this speed.

You've got to take your hat of to the Atom developers. Getting a CPU down to those power levels is impressive.

What's impressive is what we get the idle power levels down to in the upcoming generations of Atom, which will be better aimed at mobile and ultra mobile applications. If the CPU is at 100% load, though, it will burn some power.