Understanding Qualcomm's Snapdragon 810: Performance Preview
by Joshua Ho & Andrei Frumusanu on February 12, 2015 9:00 AM EST- Posted in
- SoCs
- Qualcomm
- Mobile
- Gobi
- Snapdragon 810
WTR3925
There are a few things that are important when talking about a transceiver. To recap, transceivers have a few key elements. On the receive side, we see the need for low noise amplifiers, down-converters, and narrow-band amplifiers. On the transmit side, we need a driver amplifier, up-converter, and another set of narrow-band amplifiers. While most of RF360 is built on relatively old process nodes for CMOS technology, the transceiver can be built on newer CMOS processes because it’s doesn’t have to handle the level of signal that the rest of the front end does.
At a high level, the WTR3925 really brings two new capabilities to the table. First, it does away with the need for a companion transceiver in order to achieve carrier aggregation, which the WTR1625L/WFR1620 combination provided. It seems that this is due to the need for additional ports on the transceiver, which the WTR1625L lacked. The other improvement is that WTR3925 moves to a new 28nm RF process, as opposed to the 65nm RF process used for the WTR1625L.
As a quick aside, RF processes are largely similar to CMOS processes, although with a few modifications. These changes can be thicker metal in interconnects between transistors and memcaps, which are analogous to capacitors in DRAM. Qualcomm claims that this will drive down power consumption, however this is a product of a new architecture that takes advantage of the smaller process node. Unlike digital logic such as what we see on the baseband, RF does not directly benefit from scaling to lower processes. In fact, there is a chance that scaling to lower process nodes can hurt power consumption because even though the transistor can operate faster, there is more noise As a result of this noise, the amplifiers in the transceivers may need more stages and more power in order to achieve the same noise figure.
MDM9x35
While baseband was previously one of the most popular topics in RF, as can be seen by this article RF is much more than just the baseband. However, the baseband is a critical part of the chain. The RF front end is critical for reception and a myriad of other issues, but feature support and control of the front-end lies with the baseband. The baseband must properly interpret the information that the front-end provides and also send out information to the front-end to transmit.
Fortunately, the baseband is implemented with digital logic, so there are significant benefits to moving to the latest and greatest CMOS process node. Lower voltage (and therefore power) is needed to drive the transistors, and it becomes easier to drive higher performance in the DSP. In the case of the MDM9x35, we see that there's a QDSP clocked at 800 MHz for modem functions, and a 1.2 GHz Cortex A7 for functions such as mobile hotspot.
In the case of MDM9x35, there are two major contributors to the reduction in power consumption. The first is the move from 28nm HPm to 20nm SoC. While 20nm SoC doesn’t utilize FinFET, we still see scaling in power, performance, and density. The other area where we see power savings is better implementation of various algorithms. As a result, we should see around 20-25% power savings with the same workload.
MDM9x45
In the time since the first MDM9x35 devices were launched, Qualcomm has also iterated on modems. With the 9x45 generation, we see a move to category 10 LTE, which includes 450 Mbps maximum download speed when aggregating three 20 MHz carriers, and two 20 MHz carriers on the uplink for a maximum of 100 Mbps. Although the Snapdragon 810 doesn't have a 9x45 IP block for the modem, the Snapdragon 810 does support up a maximum of 450 Mbps for download with category 9 LTE. However, there is no uplink carrier aggregation in such a scenario. Uplink carrier aggregation is only possible with category 7, which limits downlink speeds to 300 Mbps.
Qualcomm claims that the MDM9x45 should bring around 40% energy savings in an LTE carrier aggregation scenario when compared to the MDM9x25 modem. In addition, these new modems bring in a new generation of GNSS location, with support for EU's Galileo constellation. It's likely that the DSPs and other aspects of this modem have been beefed up relative to the 9x35 and 8994 modems to enable category 10 data rates.
Facebook
Twitter
RSS
119 Comments
View All Comments
JoshHo - Thursday, February 12, 2015 - link
Comparing the Snapdragon 810 to the Exynos 5433 wouldn't be of much value as the S810 won't be competing with the Exynos 5433 in flagship 2015 devices. We hope to make a valid comparison to an Exynos SoC in the near future.warreo - Thursday, February 12, 2015 - link
I disagree. This article is already primarily a comparison of S810 and S805, which like the Exynos will obviously not be competing for flagship 2015 devices. Does that make the comparison invalid? No, it's just a matter of context. People know that Exynos 5433 is an older SoC, but it's still interesting to see how S810 compares to it, just like it is interesting to see how it compares to S805.In reading this article the most interesting takeaways that I got are that on the CPU side, S810 is in a dead heat with Exynos (or barely outperforms it), and on the GPU side, there was a more substantial outperformance (call it 20-25%) vs. Exynos. The sad thing is that I had to draw that conclusion myself, because it was barely addressed in the article.
As an aside, can someone please learn me on how this performance is considered good when Exynos 7420 is right around the corner? Am I missing something?
Andrei Frumusanu - Thursday, February 12, 2015 - link
The vast majority of users will want to compare performance to the S805, seeing as the 5433 is only found in one variant of the Note 4 and probably won't bee seeing any other implementation.As for your last point, we just can't comment on performance of unreleased products.
warreo - Thursday, February 12, 2015 - link
Unfortunately, I still disagree. While most people will never use the 5433 because it is limited to the Note 4, it is still a relevant comparison because the S6 will use the 7420, which is the next iteration of the 5433. Lest we forget, there are (likely) millions of people who will buy or consider buying the S6, making the comparison against 5433 an early preview of 7420 vs. S810 which I'm willing to bet is HIGHLY interesting to readers of this site.No direct comments on the unreleased 7420 would be necessary, just a more indepth discussion on how the S810 fares against 5433 would be helpful and let readers extrapolate to 7420 themselves. The reality is, the data and benchmarks are all there, I'm just a bit mystified why it is apparently not worth the effort to add the % difference into the table and discuss those results more in the text of the article.
I'll make this my last comment on the matter as you've at least shown you've thought about the matter and had a reason as to why you didn't really discuss Exynos. I remain cynical as to whether this is a good reason (or even the true reason), but I do at least appreciate the responses. I hope you'll take my comments in the spirit in which they were given: constructive criticism to improve the quality of the article.
lopri - Thursday, February 12, 2015 - link
Millions of people considering the S6 will want to know how S810 (or rather Exynos 7420) performs compared to S600/S800/S801, because those are the platforms they are currently using. Millions of people also do not have access to the Exynos 5433 Note 4, and will not be upgrading from or to it. It would be akin to comparing some obscure Xeon CPU to widely popular Core i5 CPU.I fully expect there will be a comparison between S810 and whatever else it competes against in due time.
Jumangi - Friday, February 13, 2015 - link
Millions? Let's be real here. 99%+ of the people who go out to buy the next Galaxy phone or any smartphone for that matter won't have the slightest clue of the SoC in the thing.tdslam720 - Thursday, February 12, 2015 - link
Way to miss out on all the hype. Take some hints from Pro Wrestling or UFC. Samsung vs Qualcomm is the hype right now. Exynos vs 810 . You claim people want to see 810 vs 805, no one cares about that. Give us 810 vs Exynos and get tons more ad money while maintaining your credibility. Right now it just looks like Qualcomm is influencing you to play nice.melgross - Thursday, February 12, 2015 - link
You say no one cares about that, but that's just you saying that. Samsung doesn't sell a whole lot of Notes, particularly to the number of devices Qualcomm sells into.tdslam720 - Thursday, February 12, 2015 - link
No but they'll sell millions of S6s which is basically the same chipblzd - Thursday, February 12, 2015 - link
We should care about a CPU in a phone that we will never use? Because the next iteration perhaps we will be able to use? Um no.S800 vs S810 is what I want to know personally.