Slashdot Mirror
Inside AMD's Phenom Architecture
An anonymous reader writes "InformationWeek has uncovered some documentation which provides some details amid today's hype for AMD's announcement of its upcoming Phenom quad-core (previously code-named Agena). AMD's 10h architecture will be used in both the desktop Phenom and the Barcelona (Opteron) quads. The architecture supports wider floating-point units, can fully retire three long instructions per cycle, and has virtual machine optimizations. While the design is solid, Intel will still be first to market with 45nm quads (the first AMD's will be 65nm). Do you think this architecture will help AMD regain the lead in its multicore battle with Intel?"
I had a 2P dual-core opteron 2.6GHz box as my workstation for several months. To be honest I couldn't really find a legitimate use for it. And I was running gentoo and doing a lot of my own OSS development [re: builds].
While I think quad-cores are important for the server rooms, I just don't see the business case for personal use. It'll just be more wasted energy. Now if you could fully shut off cores [not just gate off] when it's idle, then yeah, hey bring it on. But so long as they sit there wasting 20W per core or whatever at idle, it's just wasted power.
To get an idea of it, imagine turning on a CF lamp [in addition to the lighting you already have] and leave it on 24/7. Doesn't that seem just silly? Well that's what an idling core will look like. It's in addition to the existing processing power and just sits there wasting Watts.
Tom
Someday, I'll have a real sig.
Ultimately, it's performance that makes a successful product, not gigahertz or nanometers.
Sure, the 45nm process has great potential for better performance and higher efficiency, just like faster clock speeds had great potential - until AMD made a better architecture and achieved better performance at a lower clock speed than Intel's offerings at the time.
Let's wait and see how it really performs before passing judgement.
=Smidge=
In terms of market share, no. In terms of tech yes. See Opteron v. Intel P4 Xeon for example.
Tom
Someday, I'll have a real sig.
When it comes to multi-processing scalability, AMD's Barcelone/10h/Phenm single-die four core with hypertransport inter-chip interconnects will do far better than the two-die four core shared-bus Intel chips. Also, both the old and new AMD architecture will do relatively better on 64-bit code than the Intel Core 2 architecture: Intel's micro-op fusion does not work work in 64-bit, and their 64-bit extensions are a relatively recent add on to the old Core architecture. The FPU power of the new 10h architecture will be excellent as well. On the other hand, Intel chips will remain very competitive on integer code, cache-happy benchmarks, particularly when run in 32-bit mode. Also, the SSE4 extensions of the upcoming 45nm Intel ships will help for encoding/decoding and some rendering applications, provided that the software has been properly optimized to take advantage of them.
The Athlon X2 was superior to the Pentium D. It wasn't until Core 2 Duo that Intel took the lead in desktop CPUs.
I introduce to you the Pentium D.
The enemies of Democracy are
Take another look. He's making fun of the date they mentioned (1996).
Patrick Doyle
I mod down every jackass who puts his moderation policy in his sig. Oh, wait a sec....
1996? Wow, have *I* been misled. Mid 1996 is the vintage of my Dual Pentium Pro 200Mhz, and I *really* thought that it was state-of-the-art.
Colour me disappointed...
Just another "Cubible(sic) Joe" 2 17 3061
Actually, I just got a 65W Athlon X2 4600+ from Newegg which uses less power than my current 6 year old Athlon XP 1800+. The motherboard (ECS w/ ATI 690G) I ordered supposedly is also energy efficient. I guess I could save $60 by getting a single core, but almost all single core Athlons are rated at more than 65W. Why buy a single core when it costs more long term and is slower when multi-tasking?
Craptacular indeed (great new word) - the only thing craptacularer was the Celeron D they had out at the same time, which despite the name was not dual-core. Very amusing though, watching the 'tards with enough knowledge to be dangerous and who wanted a cheap PC,
"That one's a 'D', that's got 2 processors, that makes the internet faster"
Prevailing wisdom and personal experience suggest using "-j N+1" for N CPUs. I have a 4 CPU setup at home (dual dual-core Opterons). Here's are approximate compile times for jzIntv + SDK-1600, which altogether comprise about 80,000 lines of source:
Now keep in mind, everything was in cache, so disk activity didn't factor in much at all. But, for a typical disk, I imagine the difference between N+1 and N+2 to be largely a wash. N+1 seems to be the sweet spot if the build isn't competing with anything else. Larger increments might make sense if the build is competing with other tasks (large background batch jobs) or highly latent disks (NFS, etc). But for a local build on a personal workstation? N+1.
--JoeProgram Intellivision!