AMD is including a new feature in “Bulldozer” that will help you take your performance up to next level. This feature, is called AMD Turbo CORE technology and it allows you to capture that extra power headroom between average and maximum power, turning it into more clock speed. AMD Turbo CORE is a technology that was recently introduced in the AMD Phenom™ processor, but the way AMD delivers it in Bulldozer is greatly enhanced.
AMD Turbo CORE allows customers to tap into additional clock speed headroom by allowing the processor to rise up from the base clock speed up to the TDP level, automatically unlocking extra potential for the processor. Should the processor get too close to the power limit, it does automatically step back a bit to ensure that it is continuing to operate within the specified guidelines. This allows for significantly higher maximum clock speeds.
The chart below shows how Bulldozer allows AMD to potentially capture that lost headroom and turn it back into clock speed for the processor to utilize:
- Up to 500MHz of additional clock speed available with all cores active. This means even with multiple cores active with full workloads, all cores can boost at the same time. For those customers that want to maximize their performance, they now have the tools to do it.
- Even higher boost states available with half of the cores active. AMD is not stating exactly how high processors can boost with AMD Turbo CORE, but obviously if there is room for up to 500MHz with all cores active, fewer active cores would obviously mean less power, and more headroom to recapture with AMD Turbo CORE. At launch you will see processors marketed with a base and a maximum frequency, base will reflect the actual clock speed on the processor and max will reflect the highest AMD Turbo CORE state.
- AMD Turbo CORE is deterministic, governed by power draw, not temperature as other competing products are. This means that even in warmer climates you’ll be able to take advantage of that extra headroom if you choose. This helps ensure a max frequency is workload dependent, making it more consistent and repeatable.
With Bulldozer AMD now gives customers ways to maximize their processors for various roles in the data center:
Does AMD Turbo CORE deliver a guaranteed frequency and can you just set the frequency to a higher multiplier? No, that is not how it works. AMD Turbo CORE is continually monitoring the processor power consumption to determine the maximum processor state. For simplicity’s sake, think of it as the opposite of AMD PowerNow! technology. Instead of trying to watch for usage patterns and lower the processor core to try to reduce power consumption, Turbo CORE is watching the power consumption to see how high it can move the clock speed up. The clock speed will vary but not as much as with AMD PowerNow! because it is moving over a different range and responding to different algorithms.
The diagram below is a depiction of how a typical server could utilize AMD Turbo CORE technology in conjunction with the standard P-state management through the AMD PowerNow! technology:
As you can see over time, in periods of normal activity the processor will fluctuate between the minimum frequency and the base frequency through use of the AMD PowerNow! driver, which is integrated into most modern operating systems. The fluctuation occurs in can be called the “standard zone” – the normal operating range. But, if the workload suddenly becomes much higher in utilization, you see the processor move into what is called the “boost zone” – this is where AMD Turbo CORE takes over, because of the high demands, and squeezes as much performance out of the processor that it can in order to maximize performance.
Great, butut that just pushes up the overall power. Well, yes, power always does go up with frequency, but the most important thing to remember is that this is also a variable technology; it only increases frequency based on total demand from the application. The system runs at the base frequency unless there is a need for more performance from the application, so in environments that are “bursty” you’ll vary frequency with AMD PowerNow! between base and the lowest power. If demand for performance is sustained, the processor runs between base and max, so that you are getting the most performance, but still not wasting power.
The combination of AMD PowerNow! and the new AMD Turbo CORE technology allows customers to both maximize their clock speed when they need it most, yet still keep their power in check by reducing clock frequency as the load begins to diminish.