News Focus
News Focus
icon url

alan81

12/02/05 1:28 AM

#67069 RE: chipdesigner #67066

Anand power test on Yonah...
It is HIGHLY unlikely that the test Anand ran actually got either CPU even close to TDP. During idle the Yonah should be less than 1W and certainly no more than 2W, which means that during the "Load" test the Yonah was running at about 15W. Remember also that this is in a desktop type system with excellent thermals where the case temperature is going to MUCH lower than in a laptop... that is worth at least a few watts... but of course not nearly as many watts as some people seem to think:-)
--Alan
icon url

wbmw

12/02/05 2:05 AM

#67079 RE: chipdesigner #67066

Re: 25-49W, then.

Wrong again. Read the link this time.

http://www.theinquirer.net/?article=26904

There is an E-class for Yonah that will encompass TDPs of 50 or more watts, and a T class for 25-49W. The main SKUs of Yonah are all slated to be around 31W, so they will be Ts.

Re: 36W less system consumption than an 89W TDP X2 3800 under load doesn't get you to 31W.

36W is a system power delta. In order to relate it to the CPU, you need to take the CPU and chipset into account, since these are the major configuration differences between the Intel and AMD systems.

The X2 has an integrated memory controller, so the chipset is going to dissipate far less than the Intel equivalent. The memory controller itself contributes about 5W, and other chipset differences could contribute additional power delta. The Yonah system used a 945G chipset, according to Anand, which is the desktop version (around a 20W chip).

Also, you have to realize that the 89W X2 TDP is a family TDP value, which also encompasses the 4800+ core running with additional cache and 400MHz more. My guess is that Yonah dissipates ~25W under load, given that it is also not the highest sku to be released on the current stepping. The 2.16GHz sku may dissipate closer to the 31W TDP when under load, but Anandtech used the 2.0GHz version.

The X2 *system* dissipated 36W more than this, but that included a chipset delta as well, which let's just say is 5W (may be more). That means the X2 3800+ dissipated around 66W of power, which makes sense since it is an n-3 core frequency and the X2 TDP is based on the max processor delivery current, which has a non-zero buffer to it (but then, you already know that the AMD TDP is more conservative than Intel's TDP).

The numbers all seem to add up accurately, IMO.