Slashdot Mirror
AMD's New Venice Core Shows Overclocking Potential
Vigile writes "It looks like the new Venice core processors from AMD are going to offer more than just 90nm technology through the entire line up. According to this article on PC Perspective, it is going to offer a lot of headroom for future processors as the author was able to overclock their 2.0 GHz sample to 2.8 GHz! I think I hear an FX-61 calling my name!"
I think I hear an FX-61 calling my name!
Sorry, actually, that's my Intel chip. Noisy bugger.
What real good does overclocking 2 to 2.8 really do? These cores keep getting faster and faster, yet the increase in number of floating-point operations per second achieved isn't really that spectacular. How about a more intelligent (parallel) architecture to begin with?
Take off every sig. For great justice.
Multipliers on AMD processors are unlocked in the downward direction.
An 800MHz overclock on stock cooling is absolutely incredible... But it kind of makes me wonder why AMD doesn't make the default core speed on the proc higher.
The Barton core is awesome, and AMD is just refining their game here, working with the same basic silicon for the A64 and the XP. Intel's brains are divided up among way too many incompatible irrelevent architectures.
Just my 2 cents.
What, me worry?
So what does 2.8 Ghz in AMD mean in terms of Intel performance?
Duh...
2.8Ghz -> 9081 AMD Cybermarks -> 84.7 ISO 9011:2005 quartets -> 1.7E10 Intel TruePerfs.
I think that was fairly obvious.
Or were you just trolling for Intel?
Help fight continental drift.
How about a more intelligent (parallel) architecture to begin with?
Unless you have a way around the von Neumann bottleneck, what intelligent architecture are you thinking about? Adding multiple cores will eventually hit a wall because of memory bus contention. The only solution I see is for someone to create a memory architecture that permits unlimited simultaneous memory access. At that point, fast processors will not matter much. Just have a bunch of cheap processors share a single huge memory space.
AMD chips have multipliers unlocked downwards. That means if its got a 10x or 12x multiplier, you can chose 8, 9, 10, up to the default number. It works well, even if you dont want to OC, you can turn down the multiplier and crank up the FSB for better performance.
The Doormat
If you're not outraged, then you're not paying attention.
gigahertz are a fairly useless comparison between different chip types. A 2.0 ghz AMD64 might run circles around your 2.8ghz P4, while a 1.5Ghz Pentium-M could go faster than an AMD XP 1800 without worries. Architectures make this happen. If a 2.0ghz AMD64 can go the same speed as a 2.8ghz P4, obviously the 2.0ghz AMD64 is running more instructions per megahert. This means, that each one counts for more. Thus, a .8ghz increase is a huge increase in speed. Imagine running a 2.0ghz P4. Not very fun, eh? Now, the difference between a 2.0ghz P4 and a 2.8Ghz P4 is smaller than the difference between a 2.0Ghz AMD64, and a 2.8Ghz version of the same exact chip. That is a huge speed increase!
Help Fight SPAM today!
There's plenty of explinations.
Here's some:
A) The chip is designed to run very cool. Overclocking it makes it hot, but it still runs fine. Just very hot.
B) The chip is designed to be run at higher speeds, and the initial offering is clocked-down. This gives AMD a few steps before more core/retooling work.
C) The cooler that comes with the CPU is very good.
- It's not the Macs I hate. It's Digg users. -
I think of AMD64 more as a consumer, then a flame=seeker. Is it the most powerful - NO CLUE Is it stable - YES Is it cooler - YES Is it affordable - YES Is it for a PC - YES Why should I buy anything that is more advertised, but actually too expensive. I dont buy it. Others buy it. But not me! I like my AMD :)
IRTFA and I am going to say it once:
Overclocking capabilities does not mean just speed, they mean stability under extreme circumstances, therefore granted stability under normal circumstances!
sex is better than war!
The parent is currently moderated "Insightful" -- but it isn't. It's wrong.
P = I^2 R. For a processor, the current applied to each transistor is proportional to the clock frequency and the resistance is constant, so the power consumption per transistor (ceteris paribus) rises as the square of the clock rate. For modern processors, the power consumption of the chip is basically due to the total switching power of the transistors, and thus the power consumption rises roughly as the square of clock speed.
Intel and AMD chips have completely different designs. In general, Intel chips are designed to blast through simple code very quickly (as Intel thought that's all chips would be doing by now), and AMD chips are designed to be able to handle branches and conditional code better. Also, current AMD chips have a memory controller on the chip itself rather than on a helper chip on the motherboard, which makes their memory access faster.
Before Intel hit the gHz wall, the strategy was actually working out pretty well. They were at a bit of a disandvantage in some areas, but for the most part the clock speeds were so high it didn't matter.
With the new Prescott core in Intel chips, they increased the penalty for branching in anticipation of still higher clock speeds. Those speeds never came, so they're at a disadvantage now.
At more or less the same time, AMD upgraded the memory interface of their chips, which improves performance in most areas in addition to helping them catch up with media stuff. At the same time they kept and in some cases improved their performance on branchy code. They avoided the gHz wall by improving performance without pumping clock speed.
I think Intel assumed Itanium would take over in areas that needed branchy code back when they comitted to the Pentium 4 design in the 90s. It arrived very late, and it turns out regular desktop users still need to deal with branchy code.
I rarely criticize things I don't care about.
Here is a better overview of the changes and feature additions
Hey look no pointless curley braces or semicolons... just like Python
Because, since the amount of work done by an instruction on one processor differs from the amount done by the same instruction on another processor, it was a rather _Meaningless _Indication of _Processor _Speed.
Physics has caught up with no one. Transistors are still getting smaller, but heat is on the rise, as any 2.5 Ghz water cooled G5 owner knows.
Think of it this way: work costs watts.
No matter if you do a given amount of work using a narrow speedracer architecture like P4 or PPC970, Or a wide architecture like G4, Athlon64/Opteron, Itanium or Pentium M, the work done costs watts, and generally the speedracer designs start paying more in work per watt.
The real current limitation is architecture complexity, where no one has a big enough brain to fit more than 150 million or so useful, non-cache transistors into their heads to debug the chip when there is a problem. Bob Colwell, former chief architect for Intel for the Pentium Pro/II/III/4, has spoken and written at length about this.
When he left Intel, there were perhaps 2 people left that could debug the Pentium 4.
Tejas was cancelled for this reason, as it was an even more complex version of the P4, certainly with AMD64 instructions included, possibly some EPIC (Itanium) compatibility, and a sort of SSE4 called at the time TNI or Tejas New Instructions, that were supposed to be the last straw in bringing complete vector processing to the x86 world, which Apple of course calls Altivec.
This complexity limit has caused architecture advancement to virtualy stagnate, while Moore's law marches on. 200 million transistors last year. 400 million in 2005 a billion in 2007. What to do with the transistors? Add more cores, since individual cores can not get any more complex and cache has a limited effect after 1mb, as Itanium and the G4 show. Cache is a poor substitute for a good memory bus, and after 2mb it's all crutches to keep poor architectures competitive with the better architecures out there.
Why the stagnation at 3 Ghz, or more specificly 3.06? Because that is all the northwood architecture could do, and Prescott, its replacement, was starting to hit that complexity limit and was delayed 8 months.
When Prescott arrived, it was hot, almost 175w per cm^2. This was not the process, 90nm, that caused the heat, because the Dothan (Pentium M centrino) was only 27 watts on the same process, and no one could figure out why it was so hot, so Intel got stuck, ramping clockspeed only 533 mhz in two an a half years, after doubling clockspeed to 3.06 from 1.5 in the previous 2 years.
AMD changed horses from 2.0 Ghz Athlon to 2.0 Ghz Athlon 64 and jumped 25% to 100% better perfromance, depending on the benchmark, mostly due to the integrated memory controller, not it's 64 bitness. It would take a 3.2 to 4 Ghz Athlon to match a 2.8 Ghz Athlon 64, and a 4.2 to 5.4 Pentium 4 to match it.
There is a performance race on, and a marketing bullshit race for clockspeed which may or may not mean a processor performs better..
Sounds like you have only been following the marketing bullshit race..
But then, you are an Apple owner.
If voting were effective, it would be illegal by now.
Not necessarily. A lot of CPU's fail testing at very high speeds but run with perfect stability at lower speeds. The CPU companies are profit driven, so they're happy to get some money for the CPU instead of throwing it.
Now, you can get yourself a cheaper CPU and overclock it, knowing it's probably capable of higher speeds, but there's a big risk of stability issues.
The current generations of CPU manufacturing process make very good error free batches compared to what it used to be like. So CPU's tend to work quite well at high speeds but still get badged down. That makes sense from a corporate perspective - if there is demand for a slower, cheaper CPU, you can sell into that market with higher specced CPU's. That just happens to be the way the market works.
The alternatives are untenable. It makes no sense for AMD to deliberately make a batch of CPU's specifically intended to be 2.0GHz when it costs the same as making a batch of 2.8GHz CPUs. AMD then has the *choice* of selling these CPUs at whatever speeds and prices the market demands.
Would the parent prefer than AMD make special 2GHz only CPU's to sell? Or perhaps AMD should instead only sell > $600 high end CPUs and not sell budget range CPUs at all?
This is the way the industry works. If you don't like it, feel free to go back to using transistors instead of IC's.
I am government man, come from the government. The government has sent me. -- G.I.R.