AMD's 65nm Preview Part 2 - The Plot Thickens (Updated with Information from AMD)
by Anand Lal Shimpi on December 21, 2006 12:12 AM EST- Posted in
- CPUs
Final Words
Now that the pieces are falling into place we are able to understand a bit more about the implications of AMD's move to 65nm. It's clear that these first 65nm chips, while lower power than their 90nm counterparts, aren't very good even by AMD's standards. Already weighing in at the high end of the voltage spectrum, we hope to see more overclockable, lower power offerings once AMD's 65nm ramp really starts up. It's a constantly evolving process and if this is the worst we will see, it's not terrible; AMD can only go up from here, but it does mean that you shouldn't hold your breath waiting for the right 65nm AMD to come along.
Performance and efficiency are still both Intel's fortes thanks to its Core 2 lineup, and honestly the only reason to consider Brisbane is if you currently have a Socket-AM2 motherboard. It is worth mentioning that AMD still has the lowest overall power use with its Athlon 64 X2 EE SFF processor, but in terms of performance per watt efficiency it's not all that great. We would really like to see an EE SFF successor built on AMD's 65nm process, but we have a feeling it will be a little while before we are graced with such a delicate creature.
The step back in performance with Brisbane is truly puzzling; while none of our individual application benchmarks showed a tremendous loss in performance, it's a very unusual move for AMD. The last thing AMD needs to do is take away performance, and based on its current roadmaps the higher latency L2 cache makes no sense at all. Either AMD has some larger L2 cache variants in the works that we're not aware of, or AMD's cache didn't take very kindly to the 65nm shrink. As soon as we get the official word as to why L2 access latencies jumped 66% with Brisbane we'll be sure to report it; until then we can only wonder.
We long for the good old days, when a die shrink meant ridiculously overclockable processors, back before a die shrink was coupled with a sneaky decrease in performance. While Brisbane is far from a Prescott, it's not exactly what we were hoping for from AMD's first 65nm Athlon 64 X2. Hopefully they can work out some of the process' kinks in time for the K8L launch.
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Schugy - Thursday, December 21, 2006 - link
Being able to sell more chips is not an argument for consumers but for AMD. Brisbane is not like Prescott - AMD has done a good job. Further development is needed but first 65nm units are running and are the basis for new architectures with increased transistor count.Yoshi911 - Thursday, December 21, 2006 - link
Hey all, I know that Socket 939 is obselete now but I think It'd be awesome if they'd make a 939 65nm core.. I still have my Opteron 144 at 3.1ghz on my Lanparty board and would love to see a core I could update to before the nextgen AMD achatecture makes it out.Anyone know if this is a possibilty??
Spoelie - Thursday, December 21, 2006 - link
get a 165 for 150$, overclock it to at least 2.8ghz and you have fx62 like performancethat's the best thing you will ever get on socket 939 I'm afraid, now and in the future.
peldor - Thursday, December 21, 2006 - link
Practically, it's never gonna happen. The market wouldn't be worth the effort.OcHungry - Thursday, December 21, 2006 - link
I don’t understand why anyone or any review expect stellar overclocking or performance from these 65nm’s?Did AMD promise any? No. AMD promised a transition to 65nm and on time. That’s what we all should expect and appreciate the successful transition.
Do you remember the first batch of Intel's 65nm Core 2’s? It was not as good as what you see today. Frankly I think AMD did much better in 65nm than Intel back then, and this first release is giving Core 2 due's matured chip a run for the money. After all the review here clearly shows AMD is on tract w/ 65nm’s performance per watt and energy consumption. Don’t forget its still K8 architecture competing w/ the latest and the greatest of Intel's.
IntelUser2000 - Thursday, December 21, 2006 - link
Which first batches?? The ones XS has been receiving far before the official Core 2 Duo release?? What's the OC that AT got??
http://www.anandtech.com/cpuchipsets/showdoc.aspx?...">http://www.anandtech.com/cpuchipsets/showdoc.aspx?...
X6800 went from 2.93GHz to 3.6GHz with default voltage. On a very good air cooler and voltage increased, it reached 4.0GHz.
E6700: 2.667GHz to 3.4 default, 3.9 highest
E6600: 4.0GHz highest
X6800 stock cooler highest: 3.4GHz
Tomshardware: X6800 to 3.46GHz
Xbitlabs: X6800 to 3.4GHz, 3.6GHz with +voltage
Brisbane 5000+
2.6GHz to 2.925GHz, on stock cooler, 1.475V.
It's not that bad for Brisbane IMO. It seems more like an architectural limitation than process or thermal limitation. Core 2 Duo still has ways to go and roadmaps sort of reflect it. Though the increase in L2 access latencies may mean it was done to increase the clock speed potential.
peldor - Thursday, December 21, 2006 - link
Going to 65nm shouldn't move you backwards in performance though. There's no excuse for that from the consumer's POV unless the price also goes down (certainly a possibility if yields are good).ydoucensor - Thursday, December 21, 2006 - link
could the increase in latencies have something to do with "trusted" computing and the need for attestation?fitten - Thursday, December 21, 2006 - link
Pure speculation, but the L2 latency increase may be a result of work going into the three level cache controller logic getting ready for K8L or whatever it's going to be.mino - Thursday, December 21, 2006 - link
My thoughts exactly.