65nm Athlons Debut With Lower Power Consumption

TheRaindog writes "AMD has finally rolled out Athlon 64 X2 processors based on 65nm process technology, and The Tech Report has an interesting look at their energy usage and overclocking potential compared to current 90nm models. The new 65nm chips consume less power at idle and under load than their 90nm counterparts, and appear to have plenty of headroom for overclocking. An Athlon 64 X2 5000+ that normally runs at 2.4 GHz was taken all the way up to 2.9 GHz with standard air cooling and only a marginal voltage boost, suggesting that we may see faster chips from AMD soon."

HTPC

[tedgyz]

The little gem in this story is the Athlon 64 X2 3800+ EE SFF 2.0GHz. At 35W, that sounds like a perfect CPU choice for a super-silent HTPC.

Nice but a little slower. Surprise!

[IPFreely]

Anand [anandtech.com] has a nice review of these new processors, including performance comparisons.

The surprise is that it was a little slower than it's 90nm counterpart. They chased it down to the cache latency going up from 90nm to the 65nm part.

Other than that, it looks good.

Re:It's a question of cores

[KingArthur10]

Concerning your analogy: I was thinking more along the lines that a train runs on a single track and sometimes has to be held up for another train to use the same track. They have some track switching, but most operations are serial. A car on the highway might not be allowed to go as fast as a train, but it's got four lanes to maneuver through. A bunch of cars will reach their destinations faster than a bunch of trains because the trains have to share single tracks often.

Re:HTPC

[javilon]

Do you know of any video player that will be capable of taking advantage of two processors?

As far as I know mplayer doesn't, xine doesn't and vlc doesn't.

Re:HTPC

[Neon Spiral Injector]

OK, I'll give you that. But the HD H.264 requires a huge ammount of CPU to decode. My current dual 1.6 GHz Opteron system can't do it in real time. Doesn't even come close.

So I was thinking the same thing about this new chip. It sounds pretty close to what I was wanting.

Take my advice....please

[OneSmartFellow]

If you are about to buy a AMD chip, ensure you buy a AM2 version, this is becuase non-AM2 versions do no support low level Hardware Virtualization (which means that XEN - and competitiors - can only operate in a paravirtualization mode)

65nm version marginally slower than 90nm version

[MajorJuggler]

Apparently Brisbane (65nm) has a 20-cycle L2 cache latency, vs. the 12-cycle latency from the 90nm versions. http://www.anandtech.com/cpuchipsets/showdoc.aspx? i=2893&p=3 [anandtech.com]

Re:HTPC

[Neon Spiral Injector]

Quicktime only seems to use a subset of the features of H.264. I can easily create videos that play fine with ffmpeg, but are a corrupted mess with the Quicktime player.

Re:Take my advice....please

[TheRaven64]

True, but only as far as it goes. On x86, you have four protection rings. The hypervisor lives in ring 0, the kernel gets moved to ring 1, and the apps go in ring 3 as usual. When they designed x86-64, AMD 'helpfully' removed rings 1 and 2, so now the kernel and the apps have to share the same ring. They also removed the segmented memory model, so you have to use (more expensive) paged protection mechanisms to protect guests from each other. This makes paravirtualisation more expensive on 64-bit x86 systems than 32-bit ones. If you have a system that supports HVM, you can put the Hypervisor in the special hypervisor mode, use hardware-assistance for shadow page tables, and generally implement paravirtualisation more efficiently.

I can't remember if current releases of Xen do this, but if they don't then they definitely will in the next six months.

Re:Sempron

[Endo13]

Obvious troll, but I'll bite. The 32-bit Sempron is nothing more or less than the continuation of the old 32-bit Athlon XP CPU line, and Semprons carrying the same numerical designation as their old Athlon XP counterparts have exactly the same specs. Why they changed the name I'm not exactly sure, but it's still the exact same CPU. Celerons on the other hand are just Pentiums without most of the L2 cache, which makes them heavily crippled since the P4 with its long pipeline depends very much on their on-die cache.

Re:It's a question of cores

[pclminion]

Concerning the more serious first part of your post, it seems that ideally what you want to do is dedicate one CPU/core to interactive tasks, and another core for batch tasks. That way, the interactive tasks can easily interrupt each other as often as necessary on one CPU, while the other CPU cranks along on the batch tasks with a much longer time quantum without any unnecessary interruptions.

A major disappointment for whom?

[John Jamieson]

Whenever AMD or Intel moves to a new process, they do not expect much from the first cores(they are happy if they get as many cores from a wafer as they did before-which if my sources are correct, Intel didn't do, and AMD has).
A lot of people forget that when Intel moved to 65nm, the new chips were slower in many ways, and the clock speeds were lower than the top end 90nm P4's.
By industry standards these AMD 65nm chips are a SUCCESS.

My only beef with the 65nm Athlons is that I cannot buy one at newegg, or order one from DELL. In my world, if I cannot order a PC with one, or buy it at newegg, IT IS A PAPER LAUNCH!

A follow-up on L2 cache performance

[Dr. Damage]

I have posted an update to my initial look at AMD's 65nm processors here:

http://techreport.com/onearticle.x/11486 [techreport.com]

The update addresses some anomalies in L2 cache performance and raises some possibly related questions about die sizes for the 65nm Athlon 64 X2. It appears this chip is not just a die shrink with the same performance characteristics, after all.