Okay, JC, thanks for the reply. I’m just trying to understand here. My thought has always been that the TDP figure scales well when comparing similiar tasks. Meaning this: when doing basic word processing on a 7.5 TDP chip, the cpu will consume twice as much power as doing basic word processing on a 3.5 TDP chip. (CPU only comparison here. No LCD or anything.)

Vance, your first clause answers your second. Having admitted that TDP is not the whole picture, why do you treat it as if it were?

Just because you have to be prepared to evacuate twice as much heat from part A than from part B doesn’t mean that you’ll actually need to do this over any consistent period of time. Your question is ultimately meaningless without a context. If you are running some sort of thermal virus, then, sure, the processor with the higher TDP will consume more power. If the system is utterly idle, then what matters is which processor has the better deep sleep power state. There’s no reason why this couldn’t be the processor with the higher TDP. If that’s the case, the processor with the higher TDP could actually have lower power consumption during system idle. (As a side note, most people encounter system idle way more often than thermal viruses.)

TDP is one design parameter out of many. It’s an important design parameter since people don’t like it when the chips in their computers explode. However, there’s a lot about power consumption which TDP, by itself, does not tell you. If you’re going to talk about which chips consume more power, you state under which circumstances, and most likely someone will have to do some measuring (or extrapolating from the set of numbers the manufactures give you).

in the end the whole discussion boils down to the date when those new CPUs are available in those machines.

Honestly, after reading the reviews of the Mini Note with the 1.6GHz VIA C7 M i’m a bit concerned..ok, for just the browsing session it might be ok, but that UMPC is made for more. so where’s the ISAIAH and when will it be available….

So.. JC… given that TDP isn’t the whole picture… Would it still be reasonable to say that a CPU that has a TDP of 7.5 “consumes over twice as much power” as a CPU with a TDB of 3.5?

Oran, you’re absolutely right. Manufacturers do, in fact, list all those numbers. That’s because using TDP, by itself, as an indicator of power consumption is misleading. TDP is a design parameter. It lets the system designer know how much heat the system will have to evacuate. Manufacturers are doing exactly the right things. I’m not saying that I’d like for them to do more.

My gripe is with users who behave as if TDP gives you the whole picture with respect to power consumption. It clearly doesn’t. e.g., you’ll get a better sense of battery life from average consumption.

You seem to think I have it in for the manufacturers. I don’t. I have it in for people who speak as if this one number reveals all.

you could never list actual power consumption at every possible moment under every possible circumstance, because they are infinite. personally, i am glad they decided to list the worse case scenario number as the “standard”.

James, when the Isaiah version arrives are you going to get a test unit? i would like to see how much of a performance & battery life increase there will be, i suspect alot.

Standard caveat: Please don’t confuse TDP with average power consumption. Rei cited TDP numbers. The amount of heat the cooling system has to dissipate in the worst case is not the same thing how much power a processor consumes in the average case. Using TDP as a proxy for actual power consumption is not use, especially across such different designs. (e.g., you’d expect an out of order design to have more going on at once, and thus higher average power, than an in order design, even at equivalent TDP.)

Also, benchmarks tend to be a measure of throughput, even when the unit of measure is time. In that case, it’s how much time did it take to plow through a long set of computations. Benchmarks tend not to involve user interaction. Statements about snappiness or responsiveness tend to be qualitative measures of latency, usually in terms of user interaction. Don’t mix the two up. Just because a system doesn’t deal well with heavy loads doesn’t mean that it doesn’t deal quickly with light loads (e.g. user interaction.)

In fact, the general consensus across all VIA-based devices is that they benchmark poorly but offer snappy, responsive user interfaces. So if you spend your time calculating a million digits of pi, it’s going to take much longer using a C7M than with practically any other x86 processor on the market. However, for whatever reason, it does the relatively lightweight task of dealing with the user in a snappy manner. Anecdotally, it is snappier than the A110 or Celeron M. A bunch of mobile bloggers have said the same thing. I have no idea why. I suspect it has to do with the difference between Via and Intel in how they switch between P-states.

websites like UMPCportal that post these benchmarks without power consumption numbers are worthless, not to mention amateurish (acting as if performance minus other factors is all that matters). hell, you might as well drop a quad-core desktop CPU as well, because without power consumption numbers whats the difference?

it’s also VERY misleading to do ghz-to-ghz comparisons. the Atom needs much higher ghz speeds to achieve similar performance due to design choices, it’s not a flaw. once again though, power consumption numbers would have helped negate the misleading ghz ratings.

This is really good news. I’m not interested in these new toy computers that are coming out, it’s getting this new Isaiah chip in an OQO that I’m looking forward to.

oops. somebody already said that!

Ref Atom release. the four versions from 800 to 1.8ghz should all be available in quantities now I think for the oems. big launch in June! Should be great. dont forget the boards that atom come on arfe so small that it could leave space for additional battery capacity. Also, the gpu is very interesting in the area of hardware video decoding.

All in all, lots of choice for designers and lots of choice for customers.

S

oops. somebody already said that!

Ref Atom release. the four versions from 800 to 1.8ghz should all be available in quantities now I think for the oems. big launch in June! Should be great. dont forget the boards that atom come on arfe so small that it could leave space for additional battery capacity. Also, the gpu is very interesting in the area of hardware video decoding.

All in all, lots of choice for designers and lots of choice for customers.

S

Timely.
Performance figures just in…
http://www.umpcportal.com/modules/news/article.php?storyid=1440

The results look too high to me. Maybe as a result of HT
Steve

Rei, I haven’t “trashed” any processor, I just want to make sure that realistic expectations are kept with all the buzz surrounding the Atom. I have said many times I wish HP had not used the Via C-7 M for the Mini-Note but the truth is it was all that was available at release time in that class.

The A-110 would have been a good choice although I think the 1.6 GHz Via probably outperforms it in real world testing.

I do suspect that HP will use the Isaiah in future revisions as it makes the most sense from a cost and manufacturing standpoint.

HP would be crazy not to use the Isaiah since it’s pin compatible & has fantastic performance for just 1watt more power than the Atom.

no doubt the Isaiah is going to be the best performer of the bunch & the obvious choice replacement(pin compatible). the only drawback is the Isaiah uses 3.5w compared to the Atoms 2.4w.

besides, any of the current CPU’s would have been a better choice than the lousy C7-M. even the A110 which is in the same performance league but has much lower power consumption (3.5w vs 7.5w).

the HP will receive a dramatic boost in performance AND battery life with either the Atom or Isaiah.