The Google Nexus 9 Review
by Joshua Ho & Ryan Smith on February 4, 2015 8:00 AM EST- Posted in
- Tablets
- HTC
- Project Denver
- Android
- Mobile
- NVIDIA
- Nexus 9
- Lollipop
- Android 5.0
GPU Performance
While Denver is new, the Kepler GPU in the Tegra K1 is mostly a known quantity by now. In the Nexus 9, the GPU is still a single SMX clocked to 852 MHz. In order to verify performance, we turn to our standard test suite. For the most part, our GPU-bound tests are meant to represent gaming performance although tests like 3DMark can have CPU-bound aspects while GFXBench tends towards being a pure GPU test.
The Nexus 9's GPU has effectively identical performance to what we saw in the SHIELD Tablet, which means that the Nexus 9 should be able to support a broad range of games without performance issues. There is a bit of a noticeable performance delta when comparing on-screen performance, but this is simply due to the higher resolution of the Nexus 9's display. The one notable exception is the 3DMark physics test, which seems to scale with core count quite well, and that causes Denver to fall slightly short of the quad A15 configuration.
NAND Performance
While storage performance can often be secondary to a smooth user experience, poor storage performance is extremely painful. This is similar to RAM, where the difference between 2 and 3 GB is generally academic, while the difference between 512MB and 1 GB is enormous. While there have been some issues with Androbench with the move to Android 5.0, it seems that the timer issues have since been resolved, so it's possible to resume using the results from Androbench to get a rough idea of NAND performance.
Here the Nexus 9 doesn't suffer nearly as much from full disk encryption that is forcibly enabled on the device; performance is noticeably higher than what we see in the Nexus 6. This seems to lend some credence to the theory that CPUs with ARM v8 ISA would be better suited to handling the need to encrypt and decrypt storage in real time. I tested the Nexus 9 with a custom kernel without full disk encryption to see how Androbench scores might change, but this didn't have a noticeable impact which seems to back this theory, although I'm still not confident that FDE is a good idea to enforce across all new devices.
The NAND itself, a Samsung eMMC package designated by the name BWBC3R, seems to be quite performant outside of pure sequential access, which seems to suggest that HTC hasn't skimped out in this area at all, and the use of F2FS is responsible for some of the best random I/O scores in any mobile devices we've tested thus far.
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melgross - Wednesday, February 4, 2015 - link
So, people only buy devices during the first three months?Impulses - Wednesday, February 4, 2015 - link
Apparently... Although getting the review in before February would've shut all these people up, cheapest place to get the Nexus 9 all thru the holidays was Amazon ($350 for 16GB) and they gave you until January 31 to return it regardless of when you bought it.Only reason I'm so keenly aware is I bought one as a February birthday gift, opened it last weekend just to check it was fine before the return window closed... Not much backlight bleed at all even tho it was manufacturerd in October (bought in late December), some back flex but it's going in a case anyway.
blzd - Friday, February 6, 2015 - link
What does the month of manufacture have to do with the back light bleed? You don't actually believe those "revision" rumors, do you?If you do, consider how practical it is for a hardware revision to come out 1 month after release. Then consider how one set of pictures on a Reddit post proves anything other than that their RMA worked as intended.
ToTTenTranz - Wednesday, February 4, 2015 - link
I wish more smartphone/tablet makers put as much thought into their external speakers as HTC does.Once having a HTC One M7, I simply can't go back to mono speakers at the back of devices.
Dribble - Wednesday, February 4, 2015 - link
Glad the review is here at last, next one a little bit quicker please :)UpSpin - Wednesday, February 4, 2015 - link
I have following issues with your review:1. You run webbrowser tests and derive CPU performance from it. That's nonsense! It's a web-browser test, and it won't be a CPU test whatever you do. If you want to test raw CPU performance you have to run native CPU test applications.
2. Your battery life analysis is based on false assumptions and you derive doubtful claims from it.
The error is quite evident on the iPad Air test. In your newly introduced white display test, with airplane on, CPU/GPU idling, etc. the iPad Air 2 has a battery life of 10:18 hours. Now in your web-browsing battery test with WiFi on and the CPU busy, the iPad Air 2 has a battery life of 9:76 hours. That's a difference of 4%. The Nexus 9 has a difference of 30%, the Note 4 15%, the Shield Tablet 25%.
You conclude: The Tegra K1 is inefficient. But I could also conclude that the A8 is inefficient and the Tegra K1 very efficient. The Tegra K1 needs significantly less power while idling, compared to the A8, which consumes always the same, mostly independent on the load. So finally, the A8 lacks any kind of power saving mode.
That's abstruse, but the consequence of your test. Or maybe your test is flawed from the beginning on.
3. " I suspect we’re looking at the direct result of the large battery, combined with an efficient display as the Nexus 9 can last as long as 15 hours in this test compared to the iPad Air 2’s 10 hours."
Sorry, but I don't get this either. The Nexus 9 has a 25.46 WHr battery, the iPad Air 2 a 27.3 WHr battery (+7%). The Nexus 9 has a 8.9" Display, the iPad Air 2 a 9.7". (+19% area). The resolution is the same, thus the DPI on the Nexus 9 higher. The display techonoly is the same, as you said in your analysis. So the difference must be related to something else, like a highly efficient idle SoC in the Nexus 9.
Andrei Frumusanu - Wednesday, February 4, 2015 - link
The battery life tests analysis is based on true facts on the technical workings of the SoC and its idle power states and we are confident in the resulting conclusions.JarredWalton - Wednesday, February 4, 2015 - link
Going along with what Andrei said, an SoC isn't "efficient" if it's doing no work -- the A8 may not have idle power as low as the K1-64, but when you're actually doing anything more with the tablet in question is when efficiency matters. It's clear that the Air 2 wins out over the Nexus 9 in some of those tests (GFX in particular). Doing more (or equivalent) work while using less power is efficient.Imagine this as an example of why idle power only matters so far: if you were to start comparing cars on how long they could idle instead of actual gas mileage, would anyone care? "Car XYZ can run for 20 hours off a tank while idle while Car ZYX only lasts 15 hours!" Except, neither car is actually doing what a car is suppose to do, which is take you from point A to point B.
The white screen test is merely a way to look at the idle power draw for a device, and by that we can get an idea of how much additional power is needed when the device is actually in use. Also note that it's possible due to the difference in OS that Android simply better disables certain services in the test scenario and iOS might be wasting power -- the fact that the battery life hardly changes in our Internet WiFi test even suggests that's the case.
To that end, the battery life of the N9 is still quite good. Get rid of the smartphones in the charts and it's actually pretty much class leading. But it's still odd that the NVIDIA SHIELD Tablet and iPad Air 2 only show a small drop between idle and Internet, while N9 loses 33% of its battery life.
ABR - Thursday, February 5, 2015 - link
Idle power is pretty important for real world use for tablets, for example where you are reading something and the system is just sitting there. Those "load web page then pause for xx time" test would probably be really good for measuring.JarredWalton - Thursday, February 5, 2015 - link
That's exactly what our Internet test does, which is why the 33% drop in battery life is so alarming. What exactly is going on that N9 loading a generally not too complex web page every 15 seconds or so kills battery life?