DailyTech - "Merom" TDP Not All That

Submit News

Blog: Hardware "Merom" TDP Not All That
Sven Olsen (Blog) - August 17, 2006 2:18 PM

22 comment(s) - last by hstewarth.. on Aug 20 at 11:22 AM

"Merom" runs hot, "Yonah" might be the better chip for notebooks

Intel began releasing specifications of the new Merom processor to its motherboard partners today. For those expecting Merom to increase performance over Yonah while simultaneously decreasing the thermal envelope, think again.

The top of the line Yonah processor, the T2700, has a TDP of 31W at 2.33GHz clock frequency. All Core 2 Duo Merom processors have a TDP of 34W, including the lowly 1.66GHz T5500. In comparison, the 1.66GHz Yonah rings in at 27W.

Surely with Enhanced Speed Step these numbers get better, we'd think. In "Battery Mode," all Merom processors clock down to 1GHz and 0.75V -- yet amazingly the TDP is still 20W. Yonah, which also clocks down to 1GHz in Battery Mode with a 0.95V core has a TDP of 13.1W.

Those expecting to pop in a Core 2 Duo Merom processor to alleviate an overheating MacBook Pro, look not here. Merom is a better performing processor than Yonah, but its thermals on paper show its advantages are only in performance and not in thermals at all.

Intel will counter these poor thermals with more "Low Voltage" and "Ultra Low Voltage" processors. Just a few weeks ago, Intel announced an Ultra-Low Voltage (ULV) Yonah processor running on a TDP of just 9W. Intel's newest roadmap includes the U7500, an ultra-low voltage version of Merom. However, given the fact that the normal voltage Yonahs have a lower TDP than the average Merom processor, we'd be hard pressed to think U7500 could possibly run cooler than its Yonah predecessor.

Comments

Threshold

Username
Password
remember me

This article is over a month old, voting and posting comments is disabled

RE: Ultra Low Voltage

By Master Kenobi

(blog) on 8/17/2006 4:45:48 PM , Rating: 0

The writer is confusing TDP with power usage (wattage).

Parent

RE: Ultra Low Voltage

By PT2006 on 8/17/2006 4:46:42 PM , Rating: 2

Both power consumption and TDP are written in Watts.

Parent

RE: Ultra Low Voltage

By s12033722 on 8/17/2006 5:58:45 PM , Rating: 2

It seems likely that if the TDP goes up from one processor to the other, the average consumed power will also go up. It's certainly not required that this be the case, but it does seem likely.

Parent

RE: Ultra Low Voltage

By Hare on 8/18/2006 3:09:27 AM , Rating: 2

quote:
The writer is confusing TDP with power usage (wattage).

How are these two different? If your CPU takes 25W (power usage) it definately will have 25W TDP. The current and voltage you feed in to the cpu is the power/wattage and it is 99,99% converted to heat -> TDP. Energy does not disappear...

Parent

RE: Ultra Low Voltage

By sleeprae on 8/18/2006 7:04:44 PM , Rating: 2

Exactly. For processing units, the overwhelming majority of consumed power is converted to heat. Therefore, you can state with some certainty that power consumption is approximately equal to thermal dissipation.

Parent

RE: Ultra Low Voltage

By Strunf on 8/20/2006 9:28:18 AM , Rating: 2

No the TDP is an informative value for system builders so they know what their coolers have to withstand, Intel and AMD probably pick like 1000 or soo higher clocked CPUs from a family and then measure the power consumption under different power usage conditions (idle, used at 100% ...) add to it like 30% to be on the safe side and then say its x TDP for whole family.
The power consumption on the other hand is a measurable unit that depends on the frequency of a CPU, usage and so on. It’s different for all the CPUs and even 2 2.6GHz CPU may have different power consumptions under the same conditions while having the same TDP.

A CPU may have a TDP of over 100 W and never reach it even when used at 100%, this is truer on the lower clocked CPU since they get the same TDP has their higher clocked brothers.

Parent