Does it really qualify as a 5 GHz processor if it only runs at that speed in Turbo mode? (which I assume can only kick in for a few milliseconds...) What is the "normal" speed that it can maintain for more reasonable time periods? How come this isn't mentioned in the press release?
If older chips from Intel and AMD could be overclocked to twice their baseline rates with high-end cooling, I wonder what you could clock this beast up to?
And yes there is a market for this. There are certain workloads that are simply not parallelizable -- they're linear chains of dependencies where the output of the first process goes into the second and so on and each step depends on all N-1 steps.
A classic example being numeric approximations of ordinary differential equations. Parametric curve fitting, however, is an embarrassingly parallel application of chained ODE solutions.
That is to say, for most strictly serial processes, there's an application where you'll want to run it many times on independent data.
This shows at least part of what I mean - Vishera (slightly lower clocks than what was just announced) loses to Ivy Bridge by a mile in most single-tread tests, but nearly ties in multithreaded ones.
Unfortunately, heat is precisely the reason why no one's competing on clock rates any longer. It's called a thermal wall for a reason. To be honest, this is a pretty sad thing for AMD to do. It'll be interesting to see what kind of coolers will be capable of running this thing at 5ghz all the time, if any. And, if even it is possible to run this in turbo mode all the time, what next? Can AMD make a 5.1 chip? 5.2? What would they need to compromise on?
Not even remotely the same beyond for NVIDIA besides upping the clocks. On NVIDIA GPUs, all the cores are active at all speeds. You're not going to see the equivalent of the case where 1 core at 2.6 GHZ beats 2 cores at 1.3 GHz.
Do you really want your processors going full bore 24/7 just to prove they can?
At least from what I have observed in my Intel CPU with TurboBoost, it spends nearly all of its time in the turbo modes. It's only when all the cores are being utilised, that it starts reaching its TDP limits, and throttling down. Keep in mind that, due to I/0 (like memory), the cpu isn't always in its active state (c0) even if a process is using that core 100%.
This is common on multicore Intel chips as well -- the chip itself has a max heat profile that it can't exceed, so if several of the cores are quiet a single core can go much higher than it normally can, indefinitely if it remains the primary worker and there is enough heat dissipation.
The i5 in the new Mac Air runs at 1.3Ghz if both cores are active, but if a single core is active and the environment isn't too hot and ventilation is working, a single core can hit 2.6Ghz. Which is quite humorous -- you might have much better real life performance simply disabling a core.
EDIT: To clarify, I replied because of the supposition by the parent that this turbo mode is "for a few milliseconds". In actual practice it is usually a very significant contributor to performance on modern chips, and as mentioned can be indefinite in some circumstances. Ergo, dramatically more important than implied.
AMD is behind, and they'll use gimmicks where they can. Though since nvidia came up elsewhere, note that nvidia effectively advertises their "turbo" speed as the base and max speed, but in practice you'll often find it regulated to lower speeds for heat reasons.
In this case, however, it's an 8-core chip. Very few current workloads will saturate 8 cores (even on heavily taxed database servers), meaning that there is a good chance there is always thermal availability for individual cores (and thus individual threads) to be run at 5Ghz.
> *Very few current workloads will saturate 8 cores (even on heavily taxed database servers)
It depends. Some tasks, such as processing incoming HTTP requests and building responses, such as web servers do - are embarrassingly parallelizable. And if you have an architecture that scales horizontally, with enough network bandwidth, you can saturate how many cores you want.
Oh for sure there are cases that might saturate all cores. They're just incredibly rare, even on machines that are working at "100%". The case of web servers is an interesting one because benchmarks seldom see them actually running at 100% despite putting all of their combined resources at a problem -- there is usually something else synchronously slowing the flow, or a simple bottleneck like Gbps networking. Even on virtualization servers, one generally leaves enough headroom that the machine is nowhere near saturated.
Not really. In most cases your software is single threaded anyway, unless you implement some sort of parallelism yourself and when you do that it usually should make sense. But in the end its the OS thats shuffles the threads around on the cores. If you disable a core, the others can run faster reaching higher clock speeds which might or might not be benefical to your program depending on the work it does.
