AMD's 65nm Brisbane Core Previewed: The most energy efficient AMD CPU to date
by Anand Lal Shimpi on December 14, 2006 6:08 PM EST- Posted in
- CPUs
Temperature, Overclocking and Final Words
Lower power consumption and cooler operation are both positive side effects of AMD's new 65nm process, the latter of which is exemplified by the graph below:
What we're looking at here is the core temperature of the 2nd core in all of the CPUs, under full load, as reported by Core Temp. While it's not necessarily useful (or accurate) to compare readings across two different motherboards, as is the case when looking at AMD vs. Intel, the comparisons between AMD chips alone are enough to showcase the reduction in temperature.
With both cores under load for 15 minutes (calculating Fast Fourier Transforms) the 65nm 5000+ manages to produce just about as much heat as the X2 3800+ EE SFF. While this won't always be the case, it gives you an idea of the reduction in temperatures you can expect from AMD's new 65nm chips.
What about overclockability? We were unfortunately not able to get that much more out of the new 65nm core as we could from mature 90nm chips. Our X2 5000+ was able to run at 2.925GHz, at 1.475V with stock air cooling. If equipped with better air cooling or something more exotic, reaching over 3GHz shouldn't be a problem, but we wouldn't expect to see anything too far over 3GHz.
Overall we're left with mixed feelings after playing with AMD's first 65nm chips. Power consumption is definitely reduced compared to its 90nm offerings; in our tests we saw an average reduction in total system power consumption of 14.6W thanks to the new Brisbane core. Along with the lower power draw comes lower temperatures, which is also good. For no additional cost, and given that it should help alleviate AMD's capacity constraints thanks to a smaller die, there's nothing to complain about on that front.
However we would like to see more, and we have a feeling that it may end up being the 2nd rev of 65nm CPUs from AMD that truly interest us. Just as we saw with AMD's 90nm cores, it wouldn't be too surprising to see lower TDP parts emerge as AMD's process matures. We do hope to see an Energy Efficient line of X2s built on AMD's 65nm process, although it may take some time for AMD's manufacturing to reach the point where it can offer significantly reduced TDP 65nm parts.
The tweaks and advancements that AMD can do to make its 65nm parts more attractive can only go so far; while they will boast lower power consumption and improve production numbers for AMD, what we really need is a long overdue update to the K8 architecture. AMD has already promised it and we're expecting big things by the middle of next year, but in the mean time at least things will be a little cooler on the green side.
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Anand Lal Shimpi - Friday, December 15, 2006 - link
Part 2 is coming Monday with Brisbane 4800+ results :)Take care,
Anand
Anand Lal Shimpi - Monday, December 18, 2006 - link
Just an update guys - Part 2 is ready to go, just waiting for a few clarifications from AMD on performance, memory dividers and die size of Brisbane.Take care,
Anand
OcHungry - Friday, December 15, 2006 - link
Mr. Anand, is it possible that you use Asus's Crosshair motherboard if attempting for the max overclocking of these 65nm's? It's only fair when you use top Intel board but leave out top AM2 board. I have an understanding that Asus's Crosshair board is ~ 15%-17% better performer than other boards. Also I've heard that the DFI board is a great Overclocker and you have used it on the s939 reviews. I would appreciate it if you use either board, but preferably the Asus Crosshair.Thanks.clairvoyant129 - Sunday, December 17, 2006 - link
A different motherboard won't save this sorry ass piece of junk.Anand Lal Shimpi - Friday, December 15, 2006 - link
Unfortunately I don't have either of those boards here for testing, but I'm sure I can persuade either Gary or Wes to do a follow-up with a more serious look at 65nm overclocking once I'm done with the power analysis on these chips. :)Take care,
Anand
xenon74 - Friday, December 15, 2006 - link
Jarred, why is then HT Link @ 1125Mhz on Anand's "unfortunate" OC attempt?ADDAvenger - Friday, December 15, 2006 - link
Anyone else wondering what this means for the new generation of Turion X2s?I know Santa Rosa is coming out either Q1 or Q2 this year; it's supposed to support an 800 or 400mhz FSB, depending on system load, which should drop power consumption a bit. But, as I understand it, the real battery suckers are CPU, display, and HDD. (Yeah throw in GPU too if you have discrete graphics.) But where does that leave the chipset, will Santa Rosa really do much for battery life?
If not, AMD could make serious inroads into the laptop segment. 65W is hot for a laptop, but if they can drop their desktop TDPs by about a 1/3 or 1/4, why can't they do the same for their laptop chips?
mino - Friday, December 15, 2006 - link
They can. And they will...FYI even 90nm Turions consume LESS power than Merom. (Merom is more power hungry than Yonah).
Also RS690M is about to rule the integrated market (along with RS700M for C2D). In other word AMD is gonna rule the chipset market for both platforms while beeing pretty competitive in CPU's, especially for bussiness use.
(for bussiness the features and battery life is what counts, not the absolute performance)
Johnmcl7 - Friday, December 15, 2006 - link
Not according to Anandtech:http://www.anandtech.com/cpuchipsets/showdoc.aspx?...">http://www.anandtech.com/cpuchipsets/showdoc.aspx?...
Shows power consumption to be as near as identical between the two processors.
Not sure if you are comparing Turion or Turion X2 to Merome but aside from mismatched comparisons (such as comparing the power consumption of a Turion system with onboard graphics and Merom with dedicated graphics) I've not seen like for like tests showing Turions to be more power efficient:
"Does that make the Core 2 Duo worse at power saving than Turion X2? Without equivalent setups (i.e. both using IGP or both using discrete GPUs), we can't say for certain. We can say that an ASUS W5F with a T2300 chip (1.67GHz 2MB cache) that we had at one point bottomed out at 19W in idle mode, so Core Duo and Turion X2 appear close in low power states, with Turion X2 perhaps holding a slight 1-2W advantage. Our testing of Core Duo vs. Core 2 Duo showed the CPUs to be nearly equal in power draw, so it appears AMD is equal or slightly better than Intel at minimum power draw. At maximum power draw by the CPU, Turion X2 is definitely using more power than Core 2 Duo, as even with higher performance/power components the ASUS A8JS still uses less power than the MSI TL-60 at 100% CPU load."
http://www.anandtech.com/showdoc.aspx?i=2856&p...">http://www.anandtech.com/showdoc.aspx?i=2856&p...
John
rqle - Friday, December 15, 2006 - link
Darn, was so hoping AMD 65nm would give an easy 3.3ghz+ like the intel chips =(. This chip may not reflect overall OC, but it damn hovering around my AMD range of 2.6-2.8 again. A 2.66-2.7 OC intel is > then 2.9ghz AMD. Ill just waited again.