ARM told us to expect some of the first 64-bit ARMv8 based SoCs to ship in 2014, and it looks like we're seeing just that. Today Qualcomm is officially announcing its first 64-bit SoC: the Snapdragon 410 (MSM8916). 

Given that there's no 64-bit Android available at this point, most of the pressure to go to 64-bit in the Android space is actually being driven by the OEMs who view 64-bit support as a necessary checkbox feature at this point thanks to Apple's move with the A7. Combine that with the fact that the most ready 64-bit IP from ARM is the Cortex A53 (successor to the Cortex A5/A7 line), and all of the sudden it makes sense why Qualcomm's first 64-bit mobile SoC is aimed at the mainstream market (Snapdragon 400 instead of 600/800).

I'll get to explaining ARM's Cortex A53 in a moment, but first let's look at the specs of the SoC:

Qualcomm Snapdragon 410
Internal Model Number MSM8916
Manufacturing Process 28nm LP
CPU 4 x ARM Cortex A53 1.2GHz+
GPU Qualcomm Adreno 306
Memory Interface 1 x 64-bit LPDDR2/3
Integrated Modem 9x25 core, LTE Category 4, DC-HSPA+

At a high level we're talking about four ARM Cortex A53 cores, likely running around 1.2 - 1.4GHz. Having four cores still seems like a requirement for OEMs in many emerging markets unfortunately, although I'd personally much rather see two higher clocked A53s. Qualcomm said the following about 64-bit in its 410 press-release:

"The Snapdragon 410 chipset will also be the first of many 64-bit capable processors as Qualcomm Technologies helps lead the transition of the mobile ecosystem to 64-bit processing.”

Keep in mind that Qualcomm presently uses a mix of ARM and custom developed cores in its lineup. The Snapdragon 400 line already includes ARM (Cortex A7) and Krait based designs, so the move to Cortex A53 in the Snapdragon 410 isn't unprecedented. It will be very interesting to see what happens in the higher-end SKUs. I don't assume that Qualcomm will want to have a split between 32 and 64-bit designs, which means we'll either see a 64-bit Krait successor this year or we'll see more designs that leverage ARM IP in the interim. 

As you'll see from my notes below however, ARM's Cortex A53 looks like a really good choice for Qualcomm. It's an extremely power efficient design that should be significantly faster than the Cortex A5/A7s we've seen Qualcomm use in this class of SoC in the past.

The Cortex A53 CPU cores are paired with an Adreno 306 GPU, a variant of the Adreno 305 used in Snapdragon 400 based SoCs (MSM8x28/8x26).

The Snapdragon 410 also features an updated ISP compared to previous 400 offerings, adding support for up to a 13MP primary camera (no word on max throughput however).

Snapdragon 410 also integrates a Qualcomm 9x25 based LTE modem block (also included in the Snapdragon 800/MSM8974), featuring support for LTE Category 4, DC-HSPA+ and the usual legacy 3G air interfaces.

All of these IP blocks sit behind a single-channel 64-bit LPDDR2/3 memory interface.

The SoC is built on a 28nm LP process and will be sampling in the first half of 2014, with devices shipping in the second half of 2014. Given its relatively aggressive schedule, the Snapdragon 410 may be one of the first (if not the first) Cortex A53 based SoCs in the market. 

A Brief Look at ARM's Cortex A53

ARM's Cortex A53 is a dual-issue in-order design, similar to the Cortex A7. Although the machine width is unchanged, the A53 is far more flexible in how instructions can be co-issued compared to the Cortex A7 (e.g. branch, data processing, load-store, & FP/NEON all dual-issue from both decode paths). 

The A53 is fully ISA compatible with the upcoming Cortex A57, making A53 the first ARMv8 LITTLE processor (for use in big.LITTLE) configurations with an A57

The overall pipeline depth hasn't changed compared to the Cortex A7. We're still dealing with an 8-stage pipeline (3-stage fetch pipeline + 5 stage decode/execute for integer or 7 for NEON/FP). The vast majority of instructions will execute in one cycle, leaving branch prediction as a big lever for increasing performance. ARM significantly increased branch prediction accuracy with the Cortex A53, so much that it was actually leveraged in the dual-issue, out-of-order Cortex A12. ARM also improved the back end a bit, improving datapath throughput. 

The result of all of this is a dual-issue design that's pushed pretty much as far as you can without going out-of-order. Below are some core-level performance numbers, all taken in AArch32 mode, comparing the Cortex A53 to its A5/A7 competitors:

Core Level Performance Comparison
All cores running at 1.2GHz DMIPS CoreMark SPECint2000
ARM Cortex A5 1920 - 350
ARM Cortex A7 2280 3840 420
ARM Cortex A9 r4p1 - - 468
ARM Cortex A53 2760 4440 600

Even ignoring any uplift from new instructions or 64-bit, the Cortex A53 is going to be substantially faster than its predecessors. I threw in hypothetical SPECint2000 numbers for a 1.2GHz Cortex A9 to put A53's performance in even better perspective. You should expect to see better performance than a Cortex A9r4 at the same frequencies, but the A9r4 is expected to hit much higher frequencies (e.g. 2.3GHz for Cortex A9 r4p1 in NVIDIA's Tegra 4i). 

ARM included a number of power efficiency improvements and is targeting 130mW single-core power consumption at 28nm HPM (running SPECint 2000). I'd expect slightly higher power consumption at 28nm LP but we're still talking about an extremely low power design.

I'm really excited to see what ARM's Cortex A53 can do. It's a potent little architecture, one that I wish we'd see taken to higher clock speeds and maybe even used in higher end devices at the same time. The most obvious fit for these cores however is something like the Moto G, which presently uses the 32-bit Cortex A7. Given Qualcomm's schedule, I wouldn't be surprised to see something like a Moto G update late next year with a Snapdragon 410 inside. Adding LTE and four Cortex A53s would really make that the value smartphone to beat.

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  • michael2k - Tuesday, December 10, 2013 - link

    No, Apple was unexpectedly early. Everyone had a published or announced roadmap indicating 64 bit would happen by the end of 2014; none of that has changed. Reply
  • Kvaern - Tuesday, December 10, 2013 - link


    Maybe it's my google skills but I can't find anything resembling a Qualcomm or Samsung roadmap talking about 64 bit dates prior to the A7 announcement and as you know qualcomm's cmo immediately wrote 64 bit off as a "gimmick" which does imply a thing or two about Qualcomm's priorities at the time of the announcement.
    Reply
  • michael2k - Tuesday, December 10, 2013 - link

    http://www.anandtech.com/show/6420/arms-cortex-a57...

    ARM announced the 64 bit CPUs in 10/12, and would deliver their base designs by about 6/13, with the expectation of production silicon by spring of 2014. AMD had announced it's product by 2014.

    ARM's press release: http://www.arm.com/about/newsroom/arm-launches-cor...

    ARM itself expected the first Cortex A50 based chips in 2014.

    Again, Apple shipping in 2013 was unexpectedly early.
    Reply
  • Kvaern - Tuesday, December 10, 2013 - link

    That's only ARM itself, not "everyone".

    The 410 is simply a low end reference design if I'm not mistaken, which they can get to market much faster than a 64 bit Krait and there's no Qualcomm published roadmap with a 64 bit Krait in it as far as I'm aware.
    Reply
  • michael2k - Wednesday, December 11, 2013 - link

    That's the irony isn't it?
    Apple beat ARM to market with a custom design, while Qualcomm is relying on a reference design to be first to market. Yes, Qualcomm never published a roadmap, but ARM did. I just assumed that everyone would release their parts after ARM did.
    Reply
  • fteoath64 - Thursday, December 12, 2013 - link

    I am sure Qualcomm has a Krait 64bit design but it might be late, hence the use of A53 reference design as the way to "beat the 2013" time frame in order to show the market it has some 64-bit cred. This buys time for a real Krait 64 sometime Q2 or next year when it will begin to heat up as the other Arm players begin to show their iterations of the reference A57 designs. Here is where Krait can still work its magic to capture the bulk of the market the way it did with S600. Reply
  • OreoCookie - Wednesday, December 11, 2013 - link

    There is no pressure in the Android world to switch to 64 bit earlier (Android would still run using the ARM v7s ISA). Apple, on the other hand, does have advantages switching to 64 bit on its own terms in addition to speedups. For instance, I expect Apple's 64 bit transition for their ARM-powered devices to be very smooth sailing: by the time their devices hit the 4 GB barrier, all of iOS ecosystem has moved to 64 bit long ago.

    In the Android world having a »64 bit cpu« is just a marketing checkbox at this point. However, he advantages of A53 (low power consumption, higher performance) remain even if it is run in 32 bit mode.
    Reply
  • SydneyBlue120d - Tuesday, December 10, 2013 - link

    Can't wait to preorder the Google Nexus 6 running 64bit Krait evolution with 4K HDR HEVC 60FPS IOS video support and LTE Advanced :P Reply
  • tigmd99 - Tuesday, December 10, 2013 - link

    Anand, how does A53 compare to Cyclone (from Apple A7 chip)? Reply
  • ws3 - Tuesday, December 10, 2013 - link

    http://www.sadtrombone.com/ Reply

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