Last year Qualcomm announced a new tier in its high end SoC roadmap with the Snapdragon 805. Priced somewhat above the current Snapdragon 800/801, the 805 would be the last 32-bit high-end SoC from Qualcomm. It would be the grand finale in Krait's lineage, which started back in 2012 with Krait 200 and MSM8960 and saw iterative improvements over the years. The Snapdragon 805 was not only designed to drive CPU performance higher but also be the launch vehicle for Qualcomm's brand new Adreno 4xx GPU architecture.

The Snapdragon 805 SoC is a beast. It features four Krait 450 cores, each a mild tweak of the Krait 400 design used in the S800/801. These cores can now run at up to 2.7GHz compared to 2.5GHz in the Snapdragon 801 (Krait 400). As always, Qualcomm advertises customer-friendly frequencies rounded up to the nearest 100MHz, the actual max frequency of each Krait 450 core is 2.65GHz (compared to 2.45GHz in Krait 400).

The 8% increase in max frequency comes from tuning at the circuit level, there's no impact to IPC. All four cores sit behind a shared 2MB L2 cache. As is the case with all multi-core Krait SoCs, each CPU core can be power gated, clock gated and even clocked independently of the rest.

The S805 features Qualcomm's Adreno 420 GPU with full support for OpenGL ES 3.1 (with some extensions), OpenCL 1.2 and Direct3D feature level 11_2 (with a hardware tessellation engine). In typical Qualcomm fashion, it isn't disclosing any material details on the underlying Adreno 420 architecture so we'll have to guess based on what the benchmarks tell us. Adreno 420 includes support for Adaptive Scalable Texture Compression (ASTC), a new texture compression first introduced by ARM in 2011.

There are other architectural improvements including better texturing performance and faster depth rejection. The architecture should be more efficient than Adreno 3xx as well, making better use of the underlying hardware.

The GPU runs at a max frequency of 600MHz.

Qualcomm claims a 20% reduction in power consumption compared to Adreno 330 (Snapdragon 800) when running the T-Rex HD test from GFXBench at 1080p (onscreen).

For the first time, the GPU now gets its own direct path to the SoC's memory interface. In the past the GPU shared a bus with the ISP and video engines, but in order to feed the beast that had to change. The memory interface on S805 features two 64-bit LPDDR3-800 partitions (4 x 32-bit external interfaces), each capable of supporting 1600MHz datarate LPDDR3 for an aggregate peak theoretical bandwidth figure of 25.6GB/s. The Krait 450 cores themselves aren't big enough to use all of that memory bandwidth. The wide memory interface is really there for the GPU and video engines. We haven't seen a memory interface this wide on a mobile SoC since Apple's A5X/A6X designs.

In order to accommodate the wider memory interface but still make Snapdragon 805 suitable for use in a smartphone as well as a tablet, Qualcomm turned to a different packaging technology. Since the Snapdragon 805 is an APQ part, it lacks the integrated modem of the MSM SoCs we've found in most of Qualcomm's recent flagships. S805 uses a Moulded Embedded Package (MEP) that allows Qualcomm to route its 128-bit wide memory interface to on-package DRAM, giving it all of the benefits of a PoP stack as well as the wider memory interface. Qualcomm wouldn't provide me with a ton of details on MEP other than to say that rather than using the perimeter of the SoC's package to connect to memory stacked above it, MEP uses a substrate layer on top of the SoC to connect to the memory, giving the SoC more surface area to route lines to the DRAM. Qualcomm also claims the amount of metal it uses in the DRAM's substrate layer has some small impact on improving thermals on the overall package. The result is that Snapdragon 805 is still compact enough to go into a smartphone as long as the design can accomodate a discrete modem.

The Snapdragon 805 also marks Qualcomm's first SoC with a hardware H.265/HEVC video decode engine. There's no hardware H.265 encode acceleration however, that won't come until Snapdragon 810 in 2015.

The S805's ISP sees an increase in performance as well. The SoC retains Qualcomm's dual-ISP design, now capable of pushing up to 1.2 Gigapixels/s through the engine. If Qualcomm arrives at that number the same way as it has in the past, that would imply a 600MHz ISP operating frequency (up from 465MHz in the Snapdragon 801). The new ISP supports up to four MIPI camera inputs (TrioCam + FF anyone?). The ISP can support 4k30 and 1080p120 video capture.

Qualcomm also claims improved autofocus performance and better noise reduction.

Just as in years past, Qualcomm invited us out to a benchmarking workshop to get some hands on time with its Snapdragon 805 Mobile Development Platform (MDP) ahead of actual device availability. And just like we saw with the Snapdragon 800 benchmarking workshop, the S805's MDP comes in tablet form.the Snapdragon 805 MDP/T features a 10.6" 2560 x 1440 display, 3GB of LPDDR3 memory and 64GB of internal storage (eMMC 5.0). The chassis looks very similar to previous MDP/T designs.

Just as before, the benchmarks that follow are of a pre-production device that isn't shipping hardware. Although Qualcomm has significantly improved the delta we've seen between MDPs and shipping devices, there's always the caveat that performance could be different once we are looking at a shipping device, running on battery power. Although Qualcomm gave us access to the MDP/T, the devices were running on AC power with no power instrumentation connected. Qualcomm's own data shows a reduction in power consumption for Snapdragon 805 vs. 800, but once again we'll have to wait for shipping devices to really understand the impact of the SoC on battery life. What follows is exactly what the title of this piece indicates: a preview of Snapdragon 805 performance. Although Qualcomm pre-loaded the MDP/T with some commonly used benchmarks, we installed our own copies of everything we ran.

Qualcomm's Snapdragon 8xx Lineup
  Snapdragon 810 Snapdragon 808 Snapdragon 805 Snapdragon 801 Snapdragon 800
Internal Model Number MSM8994 MSM8992 APQ8084 MSM8974 v3 MSM8974 v2
Manufacturing Process 20nm 20nm 28nm HPm 28nm HPm 28nm HPm
CPU 4 x ARM Cortex A57 + 4 x ARM Cortex A53 (big.LITTLE) 2 x ARM Cortex A57 + 4 x ARM Cortex A53 (big.LITTLE) 4 x Qualcomm Krait 450 4 x Qualcomm Krait 400 4 x Qualcomm Krait 400
ISA 32/64-bit ARMv8-A 32/64-bit ARMv8-A 32-bit ARMv7-A 32-bit ARMv7-A 32-bit ARMv7-A
GPU Adreno 430 Adreno 418 Adreno 420 Adreno 330 Adreno 330
H.265 Decode Yes Yes Yes No No
H.265 Encode Yes No No No No
Memory Interface 2 x 32-bit LPDDR4-1600 2 x 32-bit LPDDR3-933 4 x 32-bit LPDDR3-800 2 x 32-bit LPDDR3-800/933 2 x 32-bit LPDDR3-800/933
Integrated Modem 9x35 core, LTE Category 6/7, DC-HSPA+, DS-DA 9x35 core, LTE Category 6/7, DC-HSPA+, DS-DA - 9x25 core, LTE Category 4, DC-HSPA+, DS-DA 9x25 core, LTE Category 4, DC-HSPA+, DS-DA
Integrated WiFi - - - - -
eMMC Interface 5.0 5.0 5.0 5.0 4.5
Camera ISP 14-bit dual-ISP 12-bit dual-ISP 1.2 GP/s 930 MP/s 640 MP/s
Shipping in Devices 1H 2015 1H 2015 2H 2014 Now Now

I pulled comparison results from our new combined Phone/Tablet 2014 category in Bench. The key comparisons here are the iPad Air (for obvious reasons), ASUS' Transformer Pad TF701T (Tegra 4 in a tablet), ASUS' Transformer Book T100 (Intel's Bay Trail in a tablet) and the HTC One (M8)/Samsung Galaxy S 5 (both are Snapdragon 801 devices). With the exception of the Bay Trail based T100, everything else runs iOS or Android.

CPU Performance
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  • grahaman27 - Wednesday, May 21, 2014 - link

    will apple? Reply
  • Thermogenic - Thursday, May 22, 2014 - link

    It remains to be seen how good yields are for 20mm at TMSC. My guess id "not very" since Maxwell launched at 28mm. Reply
  • Kevin G - Thursday, May 22, 2014 - link

    The low end Maxwell parts also launched a bit earlier than expected. TSMC 20 nm wouldn't have been ready regardless of yields.

    The real question is if the bigger Maxwell chips will use 20 nm and when they're ready to ship.
    Reply
  • kwrzesien - Thursday, May 22, 2014 - link

    I'd really like to seem them go ahead and release the medium Maxwell on 28mm for a GTX760ti. Reply
  • testbug00 - Thursday, May 22, 2014 - link

    3 28nm dies (GM107, GM204 and GM206). One 20nm die GM200 (210?)

    GM204/206 will be october at earliest, more likely later... Hopefully not 2015, but, it could end up 2015 :(
    Reply
  • testbug00 - Thursday, May 22, 2014 - link

    Maxwell was planned to (mostly) be on 28nm years back.

    Only Maxwell silicon not on 28nm is the one that would be to large (likely, 10-12 billion transistor chip)
    Reply
  • name99 - Thursday, May 22, 2014 - link

    OR Apple was willing to pay more than nV to secure access to the limited 20nm capacity... Reply
  • retrospooty - Thursday, May 22, 2014 - link

    I am guessing not... These foundries all use same stuff. If 20nm isnt ready it isnt ready. There is pretty much TSMC, UMC (formerly AMD) and Samsung, and Intel that are capable of producing at Volume. Intel is obviously not part of this equation. I am not aware of any of the other 3 that are making 20nm chips at volume in 2014. They usually all 3 go in step at the same time. I am 99% sure the Apple A8 or whatever is in the next iPhone iPad will stil be 28nm. Reply
  • GC2:CS - Thursday, May 22, 2014 - link

    But how they will make that compulsory 2 x jump then ? Not say its impossible on 28 nm but 20nm would help a lot. Also if 28 nm it will be samsung or TSMC ? Because TSMC has more matured 28 nm process than samsung even that could be possibly enough to make that 2x jump. And hell Apple got billions to spend... Why is 20 nm so much behind the shelude ? Isn't that just Apple with an secret exclusive multibillion deal sucking off the entire TSMC ? Reply
  • tuxfool - Friday, May 23, 2014 - link

    Small Correction. UMC isn't former AMD. GF (Global Foundries) is former AMD Reply

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