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Old 02-24-2012, 08:07 PM
Hunt3r Hunt3r is offline
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Default Krait and Cortex A15

I've decided to leave out Tegra 3 in this question because it's pretty much already settled there, so now the more important question is this:

Is Krait faster than Cortex A15? Or is it the other way around? I've seen claims going both ways, so it'd be nice to be able to establish a consensus.

As a final question, is the Krait that should be in devices being shown off at MWC the same that will be powering the APQ8064? I've been reading certain comments where people were adamant that the Krait shipping now is designed to be a Cortex A9 fighter, and there will be a proper Krait to compete with Cortex A15 due to ship around the same time that Cortex A15 SoCs will be shipping in devices.
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Old 02-24-2012, 08:35 PM
kalelovil kalelovil is offline
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I would expect A15 to be faster than Krait; considering its longer development time, a higher rumoured DMIPs/Mhz (3.5 compared to 3.3 for Krait), the previous situation with Qualcomm's Scorpion and ARM's A9, and ARM's intent to challenge x86 in larger form factor devices than phones and tablets with their future designs.
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Old 02-24-2012, 08:41 PM
Hunt3r Hunt3r is offline
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Quote:
Originally Posted by kalelovil View Post
I would expect A15 to be faster than Krait; considering its longer development time, a higher rumoured DMIPs/Mhz (3.5 compared to 3.3 for Krait), the previous situation with Qualcomm's Scorpion and ARM's A9, and ARM's intent to challenge x86 in larger form factor devices than phones and tablets with their future designs.
You have a point, but Scorpion vs ARM's A8 was basically neck and neck, with the Scorpion getting a slight lead due to some better out of order processing...
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Old 02-24-2012, 09:12 PM
qwerty qwerty is offline
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Quote:
Originally Posted by Hunt3r View Post
You have a point, but Scorpion vs ARM's A8 was basically neck and neck, with the Scorpion getting a slight lead due to some better out of order processing...
Clock for clock OMAP4 or the Exynos SoC are faster than the Scorpion SoC.
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Old 02-24-2012, 09:48 PM
cal_guy cal_guy is offline
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OMAP4 is Cortex-A9 based while all Exynos SOC use or will use A9 or A15 processors with the exception of one rebranded Exynos SOC.
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Old 02-25-2012, 01:52 AM
Hunt3r Hunt3r is offline
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Quote:
Originally Posted by qwerty View Post
Clock for clock OMAP4 or the Exynos SoC are faster than the Scorpion SoC.
Yes, but you're talking about the Snapdragon S3, which is basically a lot like what Intel was doing, where they put two Pentium 4s together to make a Pentium D.

I'm saying that the previous architecture, the Snapdragon S2, was competitive with the single core Apple A4, OMAP3, and Samsung's Hummingbird. It's GPU wasn't faster than the Hummingbird, but the CPU was ever so slightly better.
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Old 02-25-2012, 02:37 AM
Third Eye Third Eye is offline
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Default Clearing some misunderstandings....

I will try to illustrate with Qualcomm vs ARM loosely as AMD vs Intel in the x86 world eventhough they are not equal but somwhat equivalent.


HTML Code:
Company   ISA     Type        Salient Points
INTEL     x-86    Owner       INTEL does not license its x86 CPU cores.
AMD       x-86    Licensee    Build MPUs/APUs based on x86 ISA 
ARM       ARMv7   Owner       ARM licenses its CPU cores
QComm     ARMv7   Licensee    Build SOCs based on ARM ISA


The previous generation Qualcomm ARM compatible CPU core was the Scorpion. Think of it like the AMD K8 family which is the start of the "Hammer" series of processors.
Snapdragon was more like a branding exercise for a tweaked scorpion core SOCs that can be made dual core. Like the K10 family which made multi-core desktop implementation to K8 but a derivative/extension to the K8 micro architecture.

Krait is the new next generation ARM CPU core from Qualcomm succeeding the Scorpion family. Like Bulldozer is a new core compared to the K8-K10.5h variants.

Enouf with x86 analogies.... ;-)

Quote:
Originally Posted by Hunt3r View Post
Is Krait faster than Cortex A15? Or is it the other way around? I've seen claims going both ways, so it'd be nice to be able to establish a consensus.
We have to wait for the real products. SMSNG, TI, NVDA,AAPL are core-licensees from ARM

Samsung is going to fab its A15 core based Exynos 5xxx series in its 32nm HKMG process.
Texas Instruments is going to fab its A15 based OMAP5 in UMCs 28nm HKMG??) process.
NVIDIA will likely do its A15 based SOCs in TSMC's 28nm HKMG process.
Apple too will likely fab its A15 based SOCs in TSMC 28nm

Krait is to be manufactured using TSMC's 28nm process. It is the only NG ARM core that currently has a development platform that is released. It will likely be the first NG core to appear in 2012. The first A15 based SOC will likely be Samsung Exynos 5xxx series which will be in late Q2/early Q3. OMAP5 is officially a late 2012 product at best.

So which of the various A15 iterations will it best and which will it fall back? No one can say for sure till the implementations are out.

Right now in the dual core A9 vs dual core Scorpion world, Samsung Exynos A9 seems to be the fastest. TI OMAP4 follows that. Snapdragon seemed to fight for the third place exchanging blows with Tegra2.
Quote:
As a final question, is the Krait that should be in devices being shown off at MWC the same that will be powering the APQ8064? I've been reading certain comments where people were adamant that the Krait shipping now is designed to be a Cortex A9 fighter, and there will be a proper Krait to compete with Cortex A15 due to ship around the same time that Cortex A15 SoCs will be shipping in devices.
Nope.

Krait is a CPU core
Adreno is a Graphics Core.


Krait's next gen competition is ARM Cortex A15
Scorpion's current gen competition is ARM Cortex A9

A Qualcomm SOC is a combination of Krait CPU core + Adreno Graphics core. With APQ8064, QComm is pairing the new generation of CPU cores with a 28nm shrink of the previous generation graphics core (which is able to clock @ 400Mhz at 28nm compared to 266MHz at 45nm).

In the future the NG Adreno cores(3xx) will be ready QComm will pair them with Krait Dual/Quad core say in APQ8066/APQ8068

Its competitors use different Graphics chips and different core combinations of them in their SOCs. NVIDIA uses its GeForce ULP designed Graphics for Tegra series. TI has licensed the PowerVR 54x series and plan to use 544MP in its OMAP5 while Samsung will be using the Mali 6xx series GPU cores. If so how many Graphic Cores will each SOC use?

So many variables are involved before we can blurt out which is the best?

Last edited by Third Eye; 02-25-2012 at 02:42 AM.
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Old 02-25-2012, 03:00 AM
pTmd pTmd is offline
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Quote:
Originally Posted by Third Eye View Post
I will try to illustrate with Qualcomm vs ARM loosely as AMD vs Intel in the x86 world eventhough they are not equal but somwhat equivalent.


HTML Code:
Company   ISA     Type                     Salient Points
INTEL     x-86    Owner and Licensee       Intel licenses x86-64 from AMD.
AMD       x-86    Owner and Licensee       AMD licenses x86 from Intel. 
ARM       ARMv7   Owner                    ARM licenses its CPU cores and ISA.
QComm     ARMv7   Licensee                 Build CPU cores based on ARM ISA.
Well, I think this is more closer to the current situation.
But anyway, it does not affect your explanation below. Nice post.

Last edited by pTmd; 02-25-2012 at 03:03 AM.
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Old 02-25-2012, 03:15 AM
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I expect them to be similar in performance but what's more important here is Qualcomm's distinction when compared to the other ARM licensees. Qualcomm is a fabless CPU designer and its relationship to ARM is, in essence, an ISA partner.

At any point in time, Qualcomm can tweak its design beyond the ARM hardware template to be more competitive. Something that Apple has been doing and is working hard on development to be even better. This is the very reason why Intel is afraid and an opportunity for AMD.
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Old 02-25-2012, 07:03 AM
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My bet is on A15 being faster.
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