Further Power Saving Mechanisms
VAO, or “Voltage Adaptive Operation” was originally a technique introduced in Steamroller, but has been adapted for Carrizo. It is common practice to apply more voltage to a CPU than is actually necessary, and this is done to prevent voltage droop. Droop occurs when the core requires more power, but the voltage delivery system cannot support it that quickly. Voltage drops, and if the CPU cannot handle it, then it will cause significant issues including crashing the machine. By applying more voltage than necessary, then droops will never cross the threshold to cause problems. The issue with this is that approximately 20% more voltage needs to be used to prevent droop.
AMD has implemented VAO to get back some of those power savings. When the processor detects when Vdd drops below the needed threshold, it will quickly respond by decreasing the operating frequency. This keeps droop from causing problems by lowering the necessary voltage needed to run the processor. Once Vdd recovers, then the processor increases the clockspeed back to the normal level. Droop is relatively uncommon, happening around 1% or less of the time in a CPU under load. Users will likely never notice the random drops in frequency.
This technology is applied to the GPU portion as well as the CPU. The combination allows AMD to improve power consumption by around 20% for the CPU and an extra 10% for the GPU. This is a big boost for battery life and a good reduction in heat production. Droop was very problematic for a long time, especially considering all the extra power needed to overcome droop.
Adaptive Voltage Frequency Scaling (AVFS) is a new way to monitor voltage and frequency across a chip. Each Excavator core has 10 AVFS modules that have around 500 frequency sensing paths. Modern silicon is very complex, and there can be variances in power delivery and frequency scaling from chip to chip. By implementing these AVFS modules, AMD is able to monitor and adjust voltage and frequency across the entire chip to optimize overall efficiency. These modules can tell when areas require more or less voltage, and adjust power delivery as needed. Instead of a “one size fits all” voltage regulation implementation, AVFS allows AMD to tailor regulation according to usage as well as silicon quality. It also adjusts for temperature, as efficiency decreases as temperature goes up in silicon.
SOi3 is a low power state that achieves the same results as the older S3 state (standby). The old S3 state was very slow to implement and was unpopular with users and OEMs. It required the OS to respond and create the necessary backup files to turn off the necessary silicon. AMD has implemented SOi3 to avoid any kind of OS interaction. It is able to shut of large portions of the APU while still keeping memory and I/O active, thereby not require the OS to take any kind of action when going to standby. It happens in less than a second and again provides very lower power consumption.
Carrizo and HSA
The promise of HSA has been talked about for years. The idea of effectively and efficiently assigning workloads to either the CPU or the GPU, depending on their strengths, is an admirable goal. It also has the promise of greater power efficiency by reducing the cycles necessary for completing a job. Kaveri was originally touted as being one of the first HSA enabled parts, but AMD has backed down from that. While Kaveri was being developed, the HSA specification was still undergoing changes. By the time Kaveri was released, the specification had changed and they were moving towards 1.0 ratification. Obviously AMD was not able to change up Kaveri to adjust for the new specification.
Carrizo will be the first HSA 1.0 compliant part from AMD (and probably the world). The one major portion of HSA that was missing in Kaveri is that of GPU Context Switching. Carrizo of course supports that functionality. This will hopefully start opening up more software capabilities and allow developers to embrace HSA.
Wrapping it Up
Carrizo will be offered from 12 watt TDP up to 35 watts. This is not to say that Carrizo cannot scale above 35 watts, it is just that it will not be offered above that for the time being. So far AMD’s higher TDP desktop parts will see a Kaveri refresh as well as the Vishera based AM3+ based parts throughout 2015. In theory Carrizo could go higher, but to get it to be as energy efficient as it is without going to a smaller process node means a lot of compromises had to be made. More power efficiency at lower frequencies typically results in lower top end frequencies combined with a higher power draw. With Carrizo, AMD aimed squarely at power efficiency at those targeted TDPs.
The power efficiency of this part looks to be very good, especially considering that it is based on the latest 28 nm process node being offered by their unannounced fabrication partner. My gut feeling here is that overall efficiency will come close to Intel’s Ivy Bridge processors, but will still trail Haswell and Broadwell. The greatest strength of this APU will be the graphics performance for the power as well as the ability to handle HSA workloads.
It seems as though a lot of the power efficiency work going into Carrizo will translate well into AMD’s next generation of products. So far AMD is aiming for 16 nm FinFET designs, but that does not preclude moving to a 14 nm FinFET process being offered by Samsung (and soon by GLOBALFOUNDRIES). If those companies can get 14 nm FF up and running in a timely manner, then AMD will be on a much closer footing to Intel in terms of process technology. Samsung has already started producing their latest Exynos SOC on 14 nm FF and are expecting final product to be released in early Q3 with the Galaxy S6 product.
AMD is hoping that Carrizo will give them a much needed boost in the mobile space, which is still an area of growth for APUs. From all indications this will be a much more competitive product to what Intel currently offers. Add in the fact that the same motherboards that will work for Carrizo will also work for the lower powered Carrizo-L products. Less complexity in the parts channel will help endear this product to OEMs.
Finally, the combination of using a very mature and (relatively) inexpensive 28 nm bulk process while having a 23% die shrink for more performance and better power efficiency should make for a less expensive and more desirable product for OEMs and consumers alike. The inclusion of the southbridge onto the SOC will also make motherboards cheaper. We will see if the actual chips have enough features, performance, and efficiency to compete well against Intel and their latest Broadwell processors that will be increasingly common when AMD finally gets Carrizo out the door in late Q2 of this year.
“Finally, the combination of
“Finally, the combination of using a very mature and (relatively) inexpensive 28 nm bulk process while having a 23% die shrink for more performance and better power efficiency should make for a less expensive and more desirable product for OEMs and consumers alike. More chips per wafer at a lower cost per wafer than cutting edge processes should help AMD make a little more margin per chip than what they have been used to as of late.”
The Die ist actually a little bit bigger than Kaveri’s due to the integration of the PCH (and other enhancements): 245 vs. 250mm².
Thanks for the clarification!
Thanks for the clarification! I had overlooked that, sadly.
How can Carrizo both
How can Carrizo both integrate the PCH and use the same old motherboard designs? What am I missing here?
Integrated components are
Integrated components are disabled when not needed by a particular setup. So it can work in either scenario.
5% IPC.
5% IPC.
5% IPC.
5%
5% IPC.
5% IPC.
5% IPC.
5% IPC.
5% IPC.
>35% over Phenom.
LE LOL.
“This change is allowing AMD
“This change is allowing AMD to enable all 8 GCN cores in even their lowest power APUs based on Carrizo.”
I feel like this is a pretty big deal; 15W chips with big 512 core GPUs should be excellent with HSA, not to mention truly mobile gaming. It’s a shame that I can never seem to find any decent AMD-based devices.
Thanks for the article Josh, great as always.
Carrizo lower cost and better
Carrizo lower cost and better than the super expensive Iris Pro 5200 graphics! I wonder if there will be laptop systems with dual integrated, and discrete AMD mobile graphics. Talk about a win win! Nice stepping stone towards ZEN, and AMD will be there with a custom ARM K12 APU and HSA compliant ARM ISA based SKUs for the tablet market, AMD could find its ARMv8a ISA based K12 a popular product for those OEMs who do not have Apple’s in house engineering resources. Nvidia dropped Denver off of the radar. AMD will have skybridge based motherboards to offer OEMs both an ARM, and x86 solutions in a pin compatible socket, saving on engineering separate motherboard solutions. Lots of interesting things coming from AMD between now and into 2016.
Who cares about parts that
Who cares about parts that arnt powerful enough to power a mechanical fly, bring on the 390x instead of having nvidia gobble up your mechanical flies for lunch!!!
And yet Intel, the so called
And yet Intel, the so called epitome of gaming, still needs Nvidia or AMD GPUs to properly high end game. These Carrizo parts have better graphics than Intel’s, and if paired with a discrete mobile GPU, with software/gaming engines tuned to AMD’s version of HSA, will be able to leverage the GPU for more than just graphics. The high end Carrizo APU has more SPs(512) than my discrete 7650m(480), and for the graphics tasks I use my laptop for, should be fine for 3d mesh modeling, not so for Intel’s stripped down integrated product, that may be acceptable for gaming(mid level gaming), but not for high polygon count mesh modeling, the more SPs the better. Carrizo’s cost will not break the bank, and I hope that Laptops are forthcoming with the high end Carrizo part, and an AMD discrete GPU, that should make for some interesting gaming/other benchmarks.
AMD should help create a demo gaming engine that could show off Carrizo’s HSA being used to accelerate gaming physics on the integrated GPU while using their discrete mobile GPU for graphics, it looks like the way AMD has structured its GPU into functional blocks that these individual blocks could be given physics tasks, while the remaining GPU blocks, both integrated and discrete, can do graphics, allowing for just the resources necessary for any GPGPU gaming acceleration, and the rest for graphics. I will be very interested in Carrizo for graphics uses, if the software is there to accelerate ray tracing on AMD’s GPU, to help alleviate the bottleneck of not having enough CPU cores for ray tracing interactions, even Intel’s core i7, with 4 cores and 8 threads takes a good while with any ray tracing tasks.
This “mechanical fly” APU that you think is weak, may just surprise in more than just the Gaming benchmarks. And I do not see Intel, or Nvidia with any SOCs, that have integrated graphics that can be used with a discrete GPU. This, Zen, and K12 are on the way, And I’ll be seriously looking at any AMD custom ARMv8a based server/workstation SKUs, as long as I could get an SKU with 16+ CPU cores, the ARMv8a ISA has support for SIMD, and the more CPU cores for ray tracing the better, at least until GPUs start getting dedicated ray tracing hardware support, The PowerVR wizard is the only one to date, but hopefully the entire industry will adopt hardware ray tracing units in GPUs.
So… VAO is basically that
So… VAO is basically that instead of CPU frequency dictating voltage, voltage dictates CPU frequecy (atleast temporarily)?
That might not have been a
That might not have been a nice way to put it.
A better way (I think) would be that VAO basically reduces voltage required to run at a particuar frequecy. Is that right?
The first guy is right.
The first guy is right. Voltage will determine frequency. So when voltage unexpectedly drops, then the frequency quickly responds to that and drops as well. It only lasts microseconds, so users shouldn't feel any burps.
This sounds like a bad thing
This sounds like a bad thing until you realize that means they can run higher clocks most of the time, since they’re now able to respond to changes so much faster!
“So far we have seen
“So far we have seen Bulldozer, Vishera, and Steamroller cores hit the market with varying levels of success. Now it is time for Excavator.”
Vishera should be Piledriver.
Beyond that, nicely writen like always.
I’m still confused why AMD is keeping the core advancement from AM3+ socket. Seeing how Zen is still 1-2 years away, this would give AM3+ a nice farewell. Or at least make a 8 core Excavator for FM2+ and I’m in.
Either way, hope the actual power/performance will be exactly what they are saying. Good luck AMD, we need competition ASAP.
Quite frankly because they
Quite frankly because they don’t have the resources to compete with Intel in that market segment.
in full agreement.
Problem is
in full agreement.
Problem is what to do with an upgrade. jump to Intel, or wait.. Guess wait and see, so FX8350 will have to do for now…
If you rely on integrated
If you rely on integrated graphics, wait for Carrizo.
If you rely on discrete graphics, wait for Pirate Islands.
Basically wait for AMD. You can always buy Intel later if none of AMD’s new products live up to the hype.
Yup, fully agreed. Wait and
Yup, fully agreed. Wait and see with AMD.
So far, Intel’s Broadwell IGP
So far, Intel’s Broadwell IGP is not looking too good. I’ve only seen the GT2 and GT3 benchmarks – not GT3e, but it looks like many newer games are still unplayable even at 720p/low. Supposedly they are DX12 compatible, but that doesn’t help the current situation.
Obviously any Intel + dGPU setup will offer the best overall performance and power savings, but it just sucks that they can’t get their mainstream IGP up to acceptable levels.
AMD does not have the money
AMD does not have the money for the contra revenue/Wink Wink, just take this fat brown envelop stuffed with Benjamins! Those laptop OEMs are sure to knuckle under, or break under some simple arm twisting, once those arms, so gently twisted behind their backs, have those non descript brown envelops shoved into their hands. That’s what does a lot of Intel’s competing in “that” market segment.
The Mobile market is another matter, and AMD will have K12, as well as Carrizo, and later Zen, to compete in the tablet market, it’s a shame that the Laptop market is so corrupted, but it will not stay that way forever, how is that Tablet market working out so far, for Intel.
Thanks, fixed.
I have no idea
Thanks, fixed.
I have no idea why AMD has not ported the advancements to AM3+. Perhaps they just don't feel the monetary means and rewards are there? Considering how little real improvement each new core set has produced over the last. Steamroller had slightly better IPC, but it was again aimed at a lower performance 28 nm process vs. 32 nm PD-SOI, so at the 4 GHz area where a new top end CPU would have been introduced… it could have had worse thermals than Piledriver and would not have overclocked as well (good luck in getting it to 5 GHz).
Carrizo is much in the same vein. It is designed for a slower process with greater efficiency. Cramming 4 modules of Excavator plus L3 cache would again likely have produced a AM3+ chip that could barely reach 4 GHz while staying in that 125 watt TDP range. The likelyhood of the design approaching 4.5 GHz is pretty low.
AMD just doesn't have the teams of engineers available to go down that many avenues at once, especially considering what Jim Keller and gang have done with future cores. Those other guys are likely busy with the new direction AMD is heading and they consider AM3+ a sidenote and a crutch until they can get the next gen stuff out on x86 and ARM.
Josh you might want to add
Josh you might want to add this to your article
http://www.3dmark.com/3dm11/9453670
3D Mark 11
P2645
with Generic VGA(1x) and AMD FX-8800P Radeon R7, 12 Compute Cores
Faster than a 740m I think.
Can AMD IGPs utilize any
Can AMD IGPs utilize any system RAM as VRAM? Does it partition it as needed? Is it manually adjustable? If I have 32GB RAM, can I use 16GB for CPU and 16GB for IGP?
You choose in the BIOS how
You choose in the BIOS how much RAM you will use for the GPU. I think usually is between 256MB and 2GBs, but those numbers could be a little different from system to system.
Good to know, thanks. I only
Good to know, thanks. I only ask because even though the IGP is limited in its rendering ability, there is a benefit to having direct access to unending amounts of VRAM for certain workloads.
I’m looking forward to the
I’m looking forward to the real results. So far sounds pretty good. I hope that the socket parity with Carrizo-L will get us a lot of laptops with either as an option.
I also wonder how 35W Carrizo will compare with “low power” (45W) Kaveri desktop chips. Would be nice if AMD could offer 35W Carrizo chips for FM2+ if they can reach the same performance as current 45W chips.
I’m hoping that just being
I’m hoping that just being able to share mainboard designs with Carrizo-L means we’ll see more AMD laptops in general (since OEMs wouldn’t need to design and support as many layouts). But yeah, if you take all of the lowend cat-core models and offer full Carrizo options as configurable upgrades that would be win-win.
This has real potential for
This has real potential for HTPC use. Low TDP allows for fanless operation (with right case). 4K decode (I do not need but I am sure others will).
If cheap and underclocked Carrizo would come in at around 25W then a small, cheap build could look great and be a perfect HTPC.
THe problem for me is at 35W, given I do not need 4K decode capability, it is no improvement on my i7-3770T which is overpowered for full HD work – so no need to upgrade
AMD is trying squeeze
AMD is trying squeeze waterout of rock, but, when you are in a position like they are in, you learn to roll with the punches.
What will make or break these chips are the devices that they might be put in by the OEMs. No one is going to buy a dinky little laptop with absolutely lousy quality hardware. These chips are powerful enough to be useful to 90% of the customer base. These are the devices I would like to see the Carrizo chips in.
Carrizo 35W parts:
Device Thickness 1″ (25mm)
Large 50WHr battery
14″-17.3″ 1080p displays (Higher resolutions are pointless with laughable scaling in Windows)
Carrizo L parts:
Device Thickness about the same (1″ or 25mm)
Large 40WHr battery
11.6″-14″ 1080p displays (Higher resolutions are pointless with laughable scaling in Windows)
You have the optional backlit keyboards, replaceable hardware (HDD to SSD, More SODIMMs, etc) and easy maintenance.
As they are using a mature process node for production, they should aim to supply as many of their flagship chips (in each category) as possible.
Price it around $500-$600 and you have something that will appeal to many.
Again, I will repeat what many have pointed out in the articles concerning this release. AMD should also make an effort to put these chips in a small barebones boxes like the Gigabyte BRIX (without a discrete GPU). Charge around $200-$250 and they would make excellent miniPCs for many.
My 2 cents.
I forgot to add….
No
I forgot to add….
No freaking discrete GPUs.
AMD graphics switching is still glitchy at best.
Good luck AMD.
Will AMD’s new CPU be able to
Will AMD’s new CPU be able to compete with Intel’s 5th generation Core i5 or even Corei7 CPU’s?
You mean this APU?
On the
You mean this APU?
On the mobile side (i5)? Sure
On desktop. Not really. Intel is sadly the only way to go for high performance single/few threaded stuff.
Am3+ CPU can compete with some multithreaded stuff. Like music production workstations etc… That demand more cores rather than high “clockspeeds”.
I wonder if it would be
I wonder if it would be worthwhile to have an HBM solution for devices with the thermal headroom to support it.
Depends on the
Depends on the implementation. HBM takes away a big bottleneck in most applications, but will add complexity and more TDP. Plus, cooling can be problematic in full 3D designs.